/* cairo - a vector graphics library with display and print output * * Copyright © 2002 University of Southern California * Copyright © 2005 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it either under the terms of the GNU Lesser General Public * License version 2.1 as published by the Free Software Foundation * (the "LGPL") or, at your option, under the terms of the Mozilla * Public License Version 1.1 (the "MPL"). If you do not alter this * notice, a recipient may use your version of this file under either * the MPL or the LGPL. * * You should have received a copy of the LGPL along with this library * in the file COPYING-LGPL-2.1; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * You should have received a copy of the MPL along with this library * in the file COPYING-MPL-1.1 * * The contents of this file are subject to the Mozilla Public License * Version 1.1 (the "License"); you may not use this file except in * compliance with the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY * OF ANY KIND, either express or implied. See the LGPL or the MPL for * the specific language governing rights and limitations. * * The Original Code is the cairo graphics library. * * The Initial Developer of the Original Code is University of Southern * California. * * Contributor(s): * Carl D. Worth <cworth@cworth.org> */ #include "cairoint.h" #include "cairo-private.h" #include "cairo-arc-private.h" #include "cairo-path-data-private.h" #define CAIRO_TOLERANCE_MINIMUM 0.0002 /* We're limited by 16 bits of sub-pixel precision */ static const cairo_t cairo_nil = { (unsigned int)-1, /* ref_count */ CAIRO_STATUS_NO_MEMORY, /* status */ { /* path */ NULL, NULL, /* op_buf_head, op_buf_tail */ NULL, NULL, /* arg_buf_head, arg_buf_tail */ { 0, 0 }, /* last_move_point */ { 0, 0 }, /* current point */ FALSE, /* has_current_point */ }, NULL /* gstate */ }; #include <assert.h> /* This has to be updated whenever cairo_status_t is extended. That's * a bit of a pain, but it should be easy to always catch as long as * one adds a new test case to test a trigger of the new status value. */ #define CAIRO_STATUS_LAST_STATUS CAIRO_STATUS_INVALID_DASH /** * _cairo_error: * @status: a status value indicating an error, (eg. not * CAIRO_STATUS_SUCCESS) * * Checks that status is an error status, but does nothing else. * * All assignments of an error status to any user-visible object * within the cairo application should result in a call to * _cairo_error(). * * The purpose of this function is to allow the user to set a * breakpoint in _cairo_error() to generate a stack trace for when the * user causes cairo to detect an error. **/ void _cairo_error (cairo_status_t status) { assert (status > CAIRO_STATUS_SUCCESS && status <= CAIRO_STATUS_LAST_STATUS); } /** * _cairo_set_error: * @cr: a cairo context * @status: a status value indicating an error, (eg. not * CAIRO_STATUS_SUCCESS) * * Sets cr->status to @status and calls _cairo_error; * * All assignments of an error status to cr->status should happen * through _cairo_set_error() or else _cairo_error() should be * called immediately after the assignment. * * The purpose of this function is to allow the user to set a * breakpoint in _cairo_error() to generate a stack trace for when the * user causes cairo to detect an error. **/ static void _cairo_set_error (cairo_t *cr, cairo_status_t status) { /* Don't overwrite an existing error. This preserves the first * error, which is the most significant. It also avoids attempting * to write to read-only data (eg. from a nil cairo_t). */ if (cr->status == CAIRO_STATUS_SUCCESS) cr->status = status; _cairo_error (status); } /** * cairo_version: * * Returns the version of the cairo library encoded in a single * integer as per CAIRO_VERSION_ENCODE. The encoding ensures that * later versions compare greater than earlier versions. * * A run-time comparison to check that cairo's version is greater than * or equal to version X.Y.Z could be performed as follows: * * <informalexample><programlisting> * if (cairo_version() >= CAIRO_VERSION_ENCODE(X,Y,Z)) {...} * </programlisting></informalexample> * * See also cairo_version_string() as well as the compile-time * equivalents %CAIRO_VERSION and %CAIRO_VERSION_STRING. * * Return value: the encoded version. **/ int cairo_version (void) { return CAIRO_VERSION; } /** * cairo_version_string: * * Returns the version of the cairo library as a human-readable string * of the form "X.Y.Z". * * See also cairo_version() as well as the compile-time equivalents * %CAIRO_VERSION_STRING and %CAIRO_VERSION. * * Return value: a string containing the version. **/ const char* cairo_version_string (void) { return CAIRO_VERSION_STRING; } /** * cairo_create: * @target: target surface for the context * * Creates a new #cairo_t with all graphics state parameters set to * default values and with @target as a target surface. The target * surface should be constructed with a backend-specific function such * as cairo_image_surface_create() (or any other * <literal>cairo_<backend>_surface_create</literal> variant). * * This function references @target, so you can immediately * call cairo_surface_destroy() on it if you don't need to * maintain a separate reference to it. * * Return value: a newly allocated #cairo_t with a reference * count of 1. The initial reference count should be released * with cairo_destroy() when you are done using the #cairo_t. * This function never returns %NULL. If memory cannot be * allocated, a special #cairo_t object will be returned on * which cairo_status() returns %CAIRO_STATUS_NO_MEMORY. * You can use this object normally, but no drawing will * be done. **/ cairo_t * cairo_create (cairo_surface_t *target) { cairo_t *cr; cr = malloc (sizeof (cairo_t)); if (cr == NULL) return (cairo_t *) &cairo_nil; cr->ref_count = 1; cr->status = CAIRO_STATUS_SUCCESS; _cairo_path_fixed_init (&cr->path); if (target == NULL) { cr->gstate = NULL; _cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER); return cr; } cr->gstate = _cairo_gstate_create (target); if (cr->gstate == NULL) _cairo_set_error (cr, CAIRO_STATUS_NO_MEMORY); return cr; } /** * cairo_reference: * @cr: a #cairo_t * * Increases the reference count on @cr by one. This prevents * @cr from being destroyed until a matching call to cairo_destroy() * is made. * * Return value: the referenced #cairo_t. **/ cairo_t * cairo_reference (cairo_t *cr) { if (cr->ref_count == (unsigned int)-1) return cr; assert (cr->ref_count > 0); cr->ref_count++; return cr; } /** * cairo_destroy: * @cr: a #cairo_t * * Decreases the reference count on @cr by one. If the result * is zero, then @cr and all associated resources are freed. * See cairo_reference(). **/ void cairo_destroy (cairo_t *cr) { if (cr->ref_count == (unsigned int)-1) return; assert (cr->ref_count > 0); cr->ref_count--; if (cr->ref_count) return; while (cr->gstate) { cairo_gstate_t *tmp = cr->gstate; cr->gstate = tmp->next; _cairo_gstate_destroy (tmp); } _cairo_path_fixed_fini (&cr->path); free (cr); } /** * cairo_save: * @cr: a #cairo_t * * Makes a copy of the current state of @cr and saves it * on an internal stack of saved states for @cr. When * cairo_restore() is called, @cr will be restored to * the saved state. Multiple calls to cairo_save() and * cairo_restore() can be nested; each call to cairo_restore() * restores the state from the matching paired cairo_save(). * * It isn't necessary to clear all saved states before * a #cairo_t is freed. If the reference count of a #cairo_t * drops to zero in response to a call to cairo_destroy(), * any saved states will be freed along with the #cairo_t. **/ void cairo_save (cairo_t *cr) { cairo_gstate_t *top; if (cr->status) return; top = _cairo_gstate_clone (cr->gstate); if (top == NULL) { _cairo_set_error (cr, CAIRO_STATUS_NO_MEMORY); return; } top->next = cr->gstate; cr->gstate = top; } slim_hidden_def(cairo_save); /** * cairo_restore: * @cr: a #cairo_t * * Restores @cr to the state saved by a preceding call to * cairo_save() and removes that state from the stack of * saved states. **/ void cairo_restore (cairo_t *cr) { cairo_gstate_t *top; if (cr->status) return; top = cr->gstate; cr->gstate = top->next; _cairo_gstate_destroy (top); if (cr->gstate == NULL) _cairo_set_error (cr, CAIRO_STATUS_INVALID_RESTORE); } slim_hidden_def(cairo_restore); /** * cairo_push_group: * @cr: a cairo context * * Pushes a CAIRO_CONTENT_COLOR_ALPHA temporary surface onto * the rendering stack, redirecting all rendering into it. * See cairo_push_group_with_content(). */ void cairo_push_group (cairo_t *cr) { cairo_push_group_with_content (cr, CAIRO_CONTENT_COLOR_ALPHA); } slim_hidden_def(cairo_push_group); /** * cairo_push_group_with_content: * @cr: a cairo context * @content: a %cairo_content_t indicating the type of group that * will be created * * Pushes a temporary surface onto the rendering stack, redirecting * all rendering into it. The surface dimensions are the size of * the current clipping bounding box. Initially, this surface * is painted with CAIRO_OPERATOR_CLEAR. * * cairo_push_group() calls cairo_save() so that any changes to the * graphics state will not be visible after cairo_pop_group() or * cairo_pop_group_with_alpha(). See cairo_pop_group() and * cairo_pop_group_with_alpha(). */ void cairo_push_group_with_content (cairo_t *cr, cairo_content_t content) { cairo_status_t status; cairo_rectangle_t extents; cairo_surface_t *group_surface = NULL; /* Get the extents that we'll use in creating our new group surface */ _cairo_surface_get_extents (_cairo_gstate_get_target (cr->gstate), &extents); status = _cairo_clip_intersect_to_rectangle (_cairo_gstate_get_clip (cr->gstate), &extents); if (status != CAIRO_STATUS_SUCCESS) goto bail; group_surface = cairo_surface_create_similar (_cairo_gstate_get_target (cr->gstate), content, extents.width, extents.height); status = cairo_surface_status (group_surface); if (status) goto bail; /* Set device offsets on the new surface so that logically it appears at * the same location on the parent surface -- when we pop_group this, * the source pattern will get fixed up for the appropriate target surface * device offsets, so we want to set our own surface offsets from /that/, * and not from the device origin. */ cairo_surface_set_device_offset (group_surface, cr->gstate->target->device_x_offset - extents.x, cr->gstate->target->device_y_offset - extents.y); /* create a new gstate for the redirect */ cairo_save (cr); if (cr->status) goto bail; _cairo_gstate_redirect_target (cr->gstate, group_surface); bail: cairo_surface_destroy (group_surface); if (status) _cairo_set_error (cr, status); } slim_hidden_def(cairo_push_group_with_content); cairo_pattern_t * cairo_pop_group (cairo_t *cr) { cairo_surface_t *group_surface, *parent_target; cairo_pattern_t *group_pattern = NULL; cairo_matrix_t group_matrix; /* Grab the active surfaces */ group_surface = _cairo_gstate_get_target (cr->gstate); parent_target = _cairo_gstate_get_parent_target (cr->gstate); /* Verify that we are at the right nesting level */ if (parent_target == NULL) { _cairo_set_error (cr, CAIRO_STATUS_INVALID_POP_GROUP); return NULL; } /* We need to save group_surface before we restore; we don't need * to reference parent_target and original_target, since the * gstate will still hold refs to them once we restore. */ cairo_surface_reference (group_surface); cairo_restore (cr); if (cr->status) goto done; group_pattern = cairo_pattern_create_for_surface (group_surface); if (!group_pattern) { cr->status = CAIRO_STATUS_NO_MEMORY; goto done; } _cairo_gstate_get_matrix (cr->gstate, &group_matrix); cairo_pattern_set_matrix (group_pattern, &group_matrix); done: cairo_surface_destroy (group_surface); return group_pattern; } slim_hidden_def(cairo_pop_group); void cairo_pop_group_to_source (cairo_t *cr) { cairo_pattern_t *group_pattern; group_pattern = cairo_pop_group (cr); if (!group_pattern) return; cairo_set_source (cr, group_pattern); cairo_pattern_destroy (group_pattern); } slim_hidden_def(cairo_pop_group_to_source); /** * cairo_set_operator: * @cr: a #cairo_t * @op: a compositing operator, specified as a #cairo_operator_t * * Sets the compositing operator to be used for all drawing * operations. See #cairo_operator_t for details on the semantics of * each available compositing operator. * * XXX: I'd also like to direct the reader's attention to some * (not-yet-written) section on cairo's imaging model. How would I do * that if such a section existed? (cworth). **/ void cairo_set_operator (cairo_t *cr, cairo_operator_t op) { if (cr->status) return; cr->status = _cairo_gstate_set_operator (cr->gstate, op); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_set_source_rgb * @cr: a cairo context * @red: red component of color * @green: green component of color * @blue: blue component of color * * Sets the source pattern within @cr to an opaque color. This opaque * color will then be used for any subsequent drawing operation until * a new source pattern is set. * * The color components are floating point numbers in the range 0 to * 1. If the values passed in are outside that range, they will be * clamped. **/ void cairo_set_source_rgb (cairo_t *cr, double red, double green, double blue) { cairo_pattern_t *pattern; if (cr->status) return; pattern = cairo_pattern_create_rgb (red, green, blue); cairo_set_source (cr, pattern); cairo_pattern_destroy (pattern); } /** * cairo_set_source_rgba: * @cr: a cairo context * @red: red component of color * @green: green component of color * @blue: blue component of color * @alpha: alpha component of color * * Sets the source pattern within @cr to a translucent color. This * color will then be used for any subsequent drawing operation until * a new source pattern is set. * * The color and alpha components are floating point numbers in the * range 0 to 1. If the values passed in are outside that range, they * will be clamped. **/ void cairo_set_source_rgba (cairo_t *cr, double red, double green, double blue, double alpha) { cairo_pattern_t *pattern; if (cr->status) return; pattern = cairo_pattern_create_rgba (red, green, blue, alpha); cairo_set_source (cr, pattern); cairo_pattern_destroy (pattern); } /** * cairo_set_source_surface: * @cr: a cairo context * @surface: a surface to be used to set the source pattern * @x: User-space X coordinate for surface origin * @y: User-space Y coordinate for surface origin * * This is a convenience function for creating a pattern from @surface * and setting it as the source in @cr with cairo_set_source(). * * The @x and @y parameters give the user-space coordinate at which * the surface origin should appear. (The surface origin is its * upper-left corner before any transformation has been applied.) The * @x and @y patterns are negated and then set as translation values * in the pattern matrix. * * Other than the initial translation pattern matrix, as described * above, all other pattern attributes, (such as its extend mode), are * set to the default values as in cairo_pattern_create_for_surface(). * The resulting pattern can be queried with cairo_get_source() so * that these attributes can be modified if desired, (eg. to create a * repeating pattern with cairo_pattern_set_extend()). **/ void cairo_set_source_surface (cairo_t *cr, cairo_surface_t *surface, double x, double y) { cairo_pattern_t *pattern; cairo_matrix_t matrix; if (cr->status) return; pattern = cairo_pattern_create_for_surface (surface); cairo_matrix_init_translate (&matrix, -x, -y); cairo_pattern_set_matrix (pattern, &matrix); cairo_set_source (cr, pattern); cairo_pattern_destroy (pattern); } /** * cairo_set_source * @cr: a cairo context * @source: a #cairo_pattern_t to be used as the source for * subsequent drawing operations. * * Sets the source pattern within @cr to @source. This pattern * will then be used for any subsequent drawing operation until a new * source pattern is set. * * Note: The pattern's transformation matrix will be locked to the * user space in effect at the time of cairo_set_source(). This means * that further modifications of the current transformation matrix * will not affect the source pattern. See cairo_pattern_set_matrix(). * * XXX: I'd also like to direct the reader's attention to some * (not-yet-written) section on cairo's imaging model. How would I do * that if such a section existed? (cworth). **/ void cairo_set_source (cairo_t *cr, cairo_pattern_t *source) { if (cr->status) return; if (source == NULL) { _cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER); return; } if (source->status) { _cairo_set_error (cr, source->status); return; } cr->status = _cairo_gstate_set_source (cr->gstate, source); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_get_source: * @cr: a cairo context * * Gets the current source pattern for @cr. * * Return value: the current source pattern. This object is owned by * cairo. To keep a reference to it, you must call * cairo_pattern_reference(). **/ cairo_pattern_t * cairo_get_source (cairo_t *cr) { if (cr->status) return (cairo_pattern_t*) &cairo_pattern_nil.base; return _cairo_gstate_get_source (cr->gstate); } /** * cairo_set_tolerance: * @cr: a #cairo_t * @tolerance: the tolerance, in device units (typically pixels) * * Sets the tolerance used when converting paths into trapezoids. * Curved segments of the path will be subdivided until the maximum * deviation between the original path and the polygonal approximation * is less than @tolerance. The default value is 0.1. A larger * value will give better performance, a smaller value, better * appearance. (Reducing the value from the default value of 0.1 * is unlikely to improve appearance significantly.) **/ void cairo_set_tolerance (cairo_t *cr, double tolerance) { if (cr->status) return; _cairo_restrict_value (&tolerance, CAIRO_TOLERANCE_MINIMUM, tolerance); cr->status = _cairo_gstate_set_tolerance (cr->gstate, tolerance); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_set_antialias: * @cr: a #cairo_t * @antialias: the new antialiasing mode * * Set the antialiasing mode of the rasterizer used for drawing shapes. * This value is a hint, and a particular backend may or may not support * a particular value. At the current time, no backend supports * %CAIRO_ANTIALIAS_SUBPIXEL when drawing shapes. * * Note that this option does not affect text rendering, instead see * cairo_font_options_set_antialias(). **/ void cairo_set_antialias (cairo_t *cr, cairo_antialias_t antialias) { if (cr->status) return; cr->status = _cairo_gstate_set_antialias (cr->gstate, antialias); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_set_fill_rule: * @cr: a #cairo_t * @fill_rule: a fill rule, specified as a #cairo_fill_rule_t * * Set the current fill rule within the cairo context. The fill rule * is used to determine which regions are inside or outside a complex * (potentially self-intersecting) path. The current fill rule affects * both cairo_fill and cairo_clip. See #cairo_fill_rule_t for details * on the semantics of each available fill rule. **/ void cairo_set_fill_rule (cairo_t *cr, cairo_fill_rule_t fill_rule) { if (cr->status) return; cr->status = _cairo_gstate_set_fill_rule (cr->gstate, fill_rule); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_set_line_width: * @cr: a #cairo_t * @width: a line width, as a user-space value * * Sets the current line width within the cairo context. The line * width specifies the diameter of a pen that is circular in * user-space. * * As with the other stroke parameters, the current line cap style is * examined by cairo_stroke(), cairo_stroke_extents(), and * cairo_stroke_to_path(), but does not have any effect during path * construction. **/ void cairo_set_line_width (cairo_t *cr, double width) { if (cr->status) return; _cairo_restrict_value (&width, 0.0, width); cr->status = _cairo_gstate_set_line_width (cr->gstate, width); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_set_line_cap: * @cr: a cairo context, as a #cairo_t * @line_cap: a line cap style, as a #cairo_line_cap_t * * Sets the current line cap style within the cairo context. See * #cairo_line_cap_t for details about how the available line cap * styles are drawn. * * As with the other stroke parameters, the current line cap style is * examined by cairo_stroke(), cairo_stroke_extents(), and * cairo_stroke_to_path(), but does not have any effect during path * construction. **/ void cairo_set_line_cap (cairo_t *cr, cairo_line_cap_t line_cap) { if (cr->status) return; cr->status = _cairo_gstate_set_line_cap (cr->gstate, line_cap); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_set_line_join: * @cr: a cairo context, as a #cairo_t * @line_join: a line joint style, as a #cairo_line_join_t * * Sets the current line join style within the cairo context. See * #cairo_line_join_t for details about how the available line join * styles are drawn. * * As with the other stroke parameters, the current line join style is * examined by cairo_stroke(), cairo_stroke_extents(), and * cairo_stroke_to_path(), but does not have any effect during path * construction. **/ void cairo_set_line_join (cairo_t *cr, cairo_line_join_t line_join) { if (cr->status) return; cr->status = _cairo_gstate_set_line_join (cr->gstate, line_join); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_set_dash: * @cr: a cairo context * @dashes: an array specifying alternate lengths of on and off po * @num_dashes: the length of the dashes array * @offset: an offset into the dash pattern at which the stroke should start * * Sets the dash pattern to be used by cairo_stroke(). A dash pattern * is specified by @dashes, an array of positive values. Each value * provides the user-space length of altenate "on" and "off" portions * of the stroke. The @offset specifies an offset into the pattern at * which the stroke begins. * * If @num_dashes is 0 dashing is disabled. * * If @num_dashes is 1 a symmetric pattern is assumed with alternating * on and off portions of the size specified by the single value in * @dashes. * * If any value in @dashes is negative, or if all values are 0, then * @cairo_t will be put into an error state with a status of * #CAIRO_STATUS_INVALID_DASH. **/ void cairo_set_dash (cairo_t *cr, double *dashes, int num_dashes, double offset) { if (cr->status) return; cr->status = _cairo_gstate_set_dash (cr->gstate, dashes, num_dashes, offset); if (cr->status) _cairo_set_error (cr, cr->status); } void cairo_set_miter_limit (cairo_t *cr, double limit) { if (cr->status) return; cr->status = _cairo_gstate_set_miter_limit (cr->gstate, limit); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_translate: * @cr: a cairo context * @tx: amount to translate in the X direction * @ty: amount to translate in the Y direction * * Modifies the current transformation matrix (CTM) by translating the * user-space origin by (@tx, @ty). This offset is interpreted as a * user-space coordinate according to the CTM in place before the new * call to cairo_translate. In other words, the translation of the * user-space origin takes place after any existing transformation. **/ void cairo_translate (cairo_t *cr, double tx, double ty) { if (cr->status) return; cr->status = _cairo_gstate_translate (cr->gstate, tx, ty); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_scale: * @cr: a cairo context * @sx: scale factor for the X dimension * @sy: scale factor for the Y dimension * * Modifies the current transformation matrix (CTM) by scaling the X * and Y user-space axes by @sx and @sy respectively. The scaling of * the axes takes place after any existing transformation of user * space. **/ void cairo_scale (cairo_t *cr, double sx, double sy) { if (cr->status) return; cr->status = _cairo_gstate_scale (cr->gstate, sx, sy); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_rotate: * @cr: a cairo context * @angle: angle (in radians) by which the user-space axes will be * rotated * * Modifies the current transformation matrix (CTM) by rotating the * user-space axes by @angle radians. The rotation of the axes takes * places after any existing transformation of user space. The * rotation direction for positive angles is from the positive X axis * toward the positive Y axis. **/ void cairo_rotate (cairo_t *cr, double angle) { if (cr->status) return; cr->status = _cairo_gstate_rotate (cr->gstate, angle); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_transform: * @cr: a cairo context * @matrix: a transformation to be applied to the user-space axes * * Modifies the current transformation matrix (CTM) by applying * @matrix as an additional transformation. The new transformation of * user space takes place after any existing transformation. **/ void cairo_transform (cairo_t *cr, const cairo_matrix_t *matrix) { if (cr->status) return; cr->status = _cairo_gstate_transform (cr->gstate, matrix); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_set_matrix: * @cr: a cairo context * @matrix: a transformation matrix from user space to device space * * Modifies the current transformation matrix (CTM) by setting it * equal to @matrix. **/ void cairo_set_matrix (cairo_t *cr, const cairo_matrix_t *matrix) { if (cr->status) return; cr->status = _cairo_gstate_set_matrix (cr->gstate, matrix); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_identity_matrix: * @cr: a cairo context * * Resets the current transformation matrix (CTM) by setting it equal * to the identity matrix. That is, the user-space and device-space * axes will be aligned and one user-space unit will transform to one * device-space unit. **/ void cairo_identity_matrix (cairo_t *cr) { if (cr->status) return; cr->status = _cairo_gstate_identity_matrix (cr->gstate); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_user_to_device: * @cr: a cairo context * @x: X value of coordinate (in/out parameter) * @y: Y value of coordinate (in/out parameter) * * Transform a coordinate from user space to device space by * multiplying the given point by the current transformation matrix * (CTM). **/ void cairo_user_to_device (cairo_t *cr, double *x, double *y) { if (cr->status) return; cr->status = _cairo_gstate_user_to_device (cr->gstate, x, y); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_user_to_device_distance: * @cr: a cairo context * @dx: X component of a distance vector (in/out parameter) * @dy: Y component of a distance vector (in/out parameter) * * Transform a distance vector from user space to device space. This * function is similar to cairo_user_to_device() except that the * translation components of the CTM will be ignored when transforming * (@dx,@dy). **/ void cairo_user_to_device_distance (cairo_t *cr, double *dx, double *dy) { if (cr->status) return; cr->status = _cairo_gstate_user_to_device_distance (cr->gstate, dx, dy); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_device_to_user: * @cr: a cairo * @x: X value of coordinate (in/out parameter) * @y: Y value of coordinate (in/out parameter) * * Transform a coordinate from device space to user space by * multiplying the given point by the inverse of the current * transformation matrix (CTM). **/ void cairo_device_to_user (cairo_t *cr, double *x, double *y) { if (cr->status) return; cr->status = _cairo_gstate_device_to_user (cr->gstate, x, y); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_device_to_user_distance: * @cr: a cairo context * @dx: X component of a distance vector (in/out parameter) * @dy: Y component of a distance vector (in/out parameter) * * Transform a distance vector from device space to user space. This * function is similar to cairo_device_to_user() except that the * translation components of the inverse CTM will be ignored when * transforming (@dx,@dy). **/ void cairo_device_to_user_distance (cairo_t *cr, double *dx, double *dy) { if (cr->status) return; cr->status = _cairo_gstate_device_to_user_distance (cr->gstate, dx, dy); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_new_path: * @cr: a cairo context * * Clears the current path. After this call there will be no current * point. **/ void cairo_new_path (cairo_t *cr) { if (cr->status) return; _cairo_path_fixed_fini (&cr->path); } slim_hidden_def(cairo_new_path); /** * cairo_move_to: * @cr: a cairo context * @x: the X coordinate of the new position * @y: the Y coordinate of the new position * * If the current subpath is not empty, begin a new subpath. After * this call the current point will be (@x, @y). **/ void cairo_move_to (cairo_t *cr, double x, double y) { cairo_fixed_t x_fixed, y_fixed; if (cr->status) return; _cairo_gstate_user_to_backend (cr->gstate, &x, &y); x_fixed = _cairo_fixed_from_double (x); y_fixed = _cairo_fixed_from_double (y); cr->status = _cairo_path_fixed_move_to (&cr->path, x_fixed, y_fixed); if (cr->status) _cairo_set_error (cr, cr->status); } slim_hidden_def(cairo_move_to); /** * cairo_line_to: * @cr: a cairo context * @x: the X coordinate of the end of the new line * @y: the Y coordinate of the end of the new line * * Adds a line to the path from the current point to position (@x, @y) * in user-space coordinates. After this call the current point * will be (@x, @y). **/ void cairo_line_to (cairo_t *cr, double x, double y) { cairo_fixed_t x_fixed, y_fixed; if (cr->status) return; _cairo_gstate_user_to_backend (cr->gstate, &x, &y); x_fixed = _cairo_fixed_from_double (x); y_fixed = _cairo_fixed_from_double (y); cr->status = _cairo_path_fixed_line_to (&cr->path, x_fixed, y_fixed); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_curve_to: * @cr: a cairo context * @x1: the X coordinate of the first control point * @y1: the Y coordinate of the first control point * @x2: the X coordinate of the second control point * @y2: the Y coordinate of the second control point * @x3: the X coordinate of the end of the curve * @y3: the Y coordinate of the end of the curve * * Adds a cubic Bézier spline to the path from the current point to * position (@x3, @y3) in user-space coordinates, using (@x1, @y1) and * (@x2, @y2) as the control points. After this call the current point * will be (@x3, @y3). **/ void cairo_curve_to (cairo_t *cr, double x1, double y1, double x2, double y2, double x3, double y3) { cairo_fixed_t x1_fixed, y1_fixed; cairo_fixed_t x2_fixed, y2_fixed; cairo_fixed_t x3_fixed, y3_fixed; if (cr->status) return; _cairo_gstate_user_to_backend (cr->gstate, &x1, &y1); _cairo_gstate_user_to_backend (cr->gstate, &x2, &y2); _cairo_gstate_user_to_backend (cr->gstate, &x3, &y3); x1_fixed = _cairo_fixed_from_double (x1); y1_fixed = _cairo_fixed_from_double (y1); x2_fixed = _cairo_fixed_from_double (x2); y2_fixed = _cairo_fixed_from_double (y2); x3_fixed = _cairo_fixed_from_double (x3); y3_fixed = _cairo_fixed_from_double (y3); cr->status = _cairo_path_fixed_curve_to (&cr->path, x1_fixed, y1_fixed, x2_fixed, y2_fixed, x3_fixed, y3_fixed); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_arc: * @cr: a cairo context * @xc: X position of the center of the arc * @yc: Y position of the center of the arc * @radius: the radius of the arc * @angle1: the start angle, in radians * @angle2: the end angle, in radians * * Adds a circular arc of the given @radius to the current path. The * arc is centered at (@xc, @yc), begins at @angle1 and proceeds in * the direction of increasing angles to end at @angle2. If @angle2 is * less than @angle1 it will be progressively increased by 2*M_PI * until it is greater than @angle1. * * If there is a current point, an initial line segment will be added * to the path to connect the current point to the beginning of the * arc. * * Angles are measured in radians. An angle of 0.0 is in the direction * of the positive X axis (in user-space). An angle of %M_PI/2.0 radians * (90 degrees) is in the direction of the positive Y axis (in * user-space). Angles increase in the direction from the positive X * axis toward the positive Y axis. So with the default transformation * matrix, angles increase in a clockwise direction. * * (To convert from degrees to radians, use <literal>degrees * (M_PI / * 180.)</literal>.) * * This function gives the arc in the direction of increasing angles; * see cairo_arc_negative() to get the arc in the direction of * decreasing angles. * * The arc is circular in user-space. To achieve an elliptical arc, * you can scale the current transformation matrix by different * amounts in the X and Y directions. For example, to draw an ellipse * in the box given by @x, @y, @width, @height: * * <informalexample><programlisting> * cairo_save (cr); * cairo_translate (x + width / 2., y + height / 2.); * cairo_scale (1. / (height / 2.), 1. / (width / 2.)); * cairo_arc (cr, 0., 0., 1., 0., 2 * M_PI); * cairo_restore (cr); * </programlisting></informalexample> **/ void cairo_arc (cairo_t *cr, double xc, double yc, double radius, double angle1, double angle2) { if (cr->status) return; /* Do nothing, successfully, if radius is <= 0 */ if (radius <= 0.0) return; while (angle2 < angle1) angle2 += 2 * M_PI; cairo_line_to (cr, xc + radius * cos (angle1), yc + radius * sin (angle1)); _cairo_arc_path (cr, xc, yc, radius, angle1, angle2); } /** * cairo_arc_negative: * @cr: a cairo context * @xc: X position of the center of the arc * @yc: Y position of the center of the arc * @radius: the radius of the arc * @angle1: the start angle, in radians * @angle2: the end angle, in radians * * Adds a circular arc of the given @radius to the current path. The * arc is centered at (@xc, @yc), begins at @angle1 and proceeds in * the direction of decreasing angles to end at @angle2. If @angle2 is * greater than @angle1 it will be progressively decreased by 2*M_PI * until it is greater than @angle1. * * See cairo_arc() for more details. This function differs only in the * direction of the arc between the two angles. **/ void cairo_arc_negative (cairo_t *cr, double xc, double yc, double radius, double angle1, double angle2) { if (cr->status) return; /* Do nothing, successfully, if radius is <= 0 */ if (radius <= 0.0) return; while (angle2 > angle1) angle2 -= 2 * M_PI; cairo_line_to (cr, xc + radius * cos (angle1), yc + radius * sin (angle1)); _cairo_arc_path_negative (cr, xc, yc, radius, angle1, angle2); } /* XXX: NYI void cairo_arc_to (cairo_t *cr, double x1, double y1, double x2, double y2, double radius) { if (cr->status) return; cr->status = _cairo_gstate_arc_to (cr->gstate, x1, y1, x2, y2, radius); } */ /** * cairo_rel_move_to: * @cr: a cairo context * @dx: the X offset * @dy: the Y offset * * If the current subpath is not empty, begin a new subpath. After * this call the current point will offset by (@x, @y). * * Given a current point of (x, y), cairo_rel_move_to(@cr, @dx, @dy) * is logically equivalent to cairo_move_to (@cr, x + @dx, y + @dy). **/ void cairo_rel_move_to (cairo_t *cr, double dx, double dy) { cairo_fixed_t dx_fixed, dy_fixed; if (cr->status) return; _cairo_gstate_user_to_device_distance (cr->gstate, &dx, &dy); dx_fixed = _cairo_fixed_from_double (dx); dy_fixed = _cairo_fixed_from_double (dy); cr->status = _cairo_path_fixed_rel_move_to (&cr->path, dx_fixed, dy_fixed); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_rel_line_to: * @cr: a cairo context * @dx: the X offset to the end of the new line * @dy: the Y offset to the end of the new line * * Relative-coordinate version of cairo_line_to(). Adds a line to the * path from the current point to a point that is offset from the * current point by (@dx, @dy) in user space. After this call the * current point will be offset by (@dx, @dy). * * Given a current point of (x, y), cairo_rel_line_to(@cr, @dx, @dy) * is logically equivalent to cairo_line_to (@cr, x + @dx, y + @dy). **/ void cairo_rel_line_to (cairo_t *cr, double dx, double dy) { cairo_fixed_t dx_fixed, dy_fixed; if (cr->status) return; _cairo_gstate_user_to_device_distance (cr->gstate, &dx, &dy); dx_fixed = _cairo_fixed_from_double (dx); dy_fixed = _cairo_fixed_from_double (dy); cr->status = _cairo_path_fixed_rel_line_to (&cr->path, dx_fixed, dy_fixed); if (cr->status) _cairo_set_error (cr, cr->status); } slim_hidden_def(cairo_rel_line_to); /** * cairo_rel_curve_to: * @cr: a cairo context * @dx1: the X offset to the first control point * @dy1: the Y offset to the first control point * @dx2: the X offset to the second control point * @dy2: the Y offset to the second control point * @dx3: the X offset to the end of the curve * @dy3: the Y offset to the end of the curve * * Relative-coordinate version of cairo_curve_to(). All offsets are * relative to the current point. Adds a cubic Bézier spline to the * path from the current point to a point offset from the current * point by (@dx3, @dy3), using points offset by (@dx1, @dy1) and * (@dx2, @dy2) as the control points. After this call the current * point will be offset by (@dx3, @dy3). * * Given a current point of (x, y), cairo_rel_curve_to (@cr, @dx1, * @dy1, @dx2, @dy2, @dx3, @dy3) is logically equivalent to * cairo_curve_to (@cr, x + @dx1, y + @dy1, x + @dx2, y + @dy2, x + * @dx3, y + @dy3). **/ void cairo_rel_curve_to (cairo_t *cr, double dx1, double dy1, double dx2, double dy2, double dx3, double dy3) { cairo_fixed_t dx1_fixed, dy1_fixed; cairo_fixed_t dx2_fixed, dy2_fixed; cairo_fixed_t dx3_fixed, dy3_fixed; if (cr->status) return; _cairo_gstate_user_to_device_distance (cr->gstate, &dx1, &dy1); _cairo_gstate_user_to_device_distance (cr->gstate, &dx2, &dy2); _cairo_gstate_user_to_device_distance (cr->gstate, &dx3, &dy3); dx1_fixed = _cairo_fixed_from_double (dx1); dy1_fixed = _cairo_fixed_from_double (dy1); dx2_fixed = _cairo_fixed_from_double (dx2); dy2_fixed = _cairo_fixed_from_double (dy2); dx3_fixed = _cairo_fixed_from_double (dx3); dy3_fixed = _cairo_fixed_from_double (dy3); cr->status = _cairo_path_fixed_rel_curve_to (&cr->path, dx1_fixed, dy1_fixed, dx2_fixed, dy2_fixed, dx3_fixed, dy3_fixed); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_rectangle: * @cr: a cairo context * @x: the X coordinate of the top left corner of the rectangle * @y: the Y coordinate to the top left corner of the rectangle * @width: the width of the rectangle * @height: the height of the rectangle * * Adds a closed-subpath rectangle of the given size to the current * path at position (@x, @y) in user-space coordinates. * * This function is logically equivalent to: * <informalexample><programlisting> * cairo_move_to (cr, x, y); * cairo_rel_line_to (cr, width, 0); * cairo_rel_line_to (cr, 0, height); * cairo_rel_line_to (cr, -width, 0); * cairo_close_path (cr); * </programlisting></informalexample> **/ void cairo_rectangle (cairo_t *cr, double x, double y, double width, double height) { if (cr->status) return; cairo_move_to (cr, x, y); cairo_rel_line_to (cr, width, 0); cairo_rel_line_to (cr, 0, height); cairo_rel_line_to (cr, -width, 0); cairo_close_path (cr); } /* XXX: NYI void cairo_stroke_to_path (cairo_t *cr) { if (cr->status) return; cr->status = _cairo_gstate_stroke_path (cr->gstate); if (cr->status) _cairo_set_error (cr, cr->status); } */ /** * cairo_close_path: * @cr: a cairo context * * Adds a line segment to the path from the current point to the * beginning of the current subpath, (the most recent point passed to * cairo_move_to()), and closes this subpath. * * The behavior of cairo_close_path() is distinct from simply calling * cairo_line_to() with the equivalent coordinate in the case of * stroking. When a closed subpath is stroked, there are no caps on * the ends of the subpath. Instead, their is a line join connecting * the final and initial segments of the subpath. **/ void cairo_close_path (cairo_t *cr) { if (cr->status) return; cr->status = _cairo_path_fixed_close_path (&cr->path); if (cr->status) _cairo_set_error (cr, cr->status); } slim_hidden_def(cairo_close_path); /** * cairo_paint: * @cr: a cairo context * * A drawing operator that paints the current source everywhere within * the current clip region. **/ void cairo_paint (cairo_t *cr) { if (cr->status) return; cr->status = _cairo_gstate_paint (cr->gstate); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_paint_with_alpha: * @cr: a cairo context * @alpha: alpha value, between 0 (transparent) and 1 (opaque) * * A drawing operator that paints the current source everywhere within * the current clip region using a mask of constant alpha value * @alpha. The effect is similar to cairo_paint(), but the drawing * is faded out using the alpha value. **/ void cairo_paint_with_alpha (cairo_t *cr, double alpha) { cairo_color_t color; cairo_pattern_union_t pattern; if (cr->status) return; if (CAIRO_ALPHA_IS_OPAQUE (alpha)) { cairo_paint (cr); return; } if (CAIRO_ALPHA_IS_ZERO (alpha)) { return; } _cairo_color_init_rgba (&color, 1., 1., 1., alpha); _cairo_pattern_init_solid (&pattern.solid, &color); cr->status = _cairo_gstate_mask (cr->gstate, &pattern.base); if (cr->status) _cairo_set_error (cr, cr->status); _cairo_pattern_fini (&pattern.base); } /** * cairo_mask: * @cr: a cairo context * @pattern: a #cairo_pattern_t * * A drawing operator that paints the current source * using the alpha channel of @pattern as a mask. (Opaque * areas of @mask are painted with the source, transparent * areas are not painted.) */ void cairo_mask (cairo_t *cr, cairo_pattern_t *pattern) { if (cr->status) return; if (pattern == NULL) { _cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER); return; } if (pattern->status) { _cairo_set_error (cr, pattern->status); return; } cr->status = _cairo_gstate_mask (cr->gstate, pattern); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_mask_surface: * @cr: a cairo context * @surface: a #cairo_surface_t * @surface_x: X coordinate at which to place the origin of @surface * @surface_y: Y coordinate at which to place the origin of @surface * * A drawing operator that paints the current source * using the alpha channel of @surface as a mask. (Opaque * areas of @surface are painted with the source, transparent * areas are not painted.) */ void cairo_mask_surface (cairo_t *cr, cairo_surface_t *surface, double surface_x, double surface_y) { cairo_pattern_t *pattern; cairo_matrix_t matrix; if (cr->status) return; pattern = cairo_pattern_create_for_surface (surface); cairo_matrix_init_translate (&matrix, - surface_x, - surface_y); cairo_pattern_set_matrix (pattern, &matrix); cairo_mask (cr, pattern); cairo_pattern_destroy (pattern); } /** * cairo_stroke: * @cr: a cairo context * * A drawing operator that strokes the current path according to the * current line width, line join, line cap, and dash settings. After * cairo_stroke, the current path will be cleared from the cairo * context. See cairo_set_line_width(), cairo_set_line_join(), * cairo_set_line_cap(), cairo_set_dash(), and * cairo_stroke_preserve(). **/ void cairo_stroke (cairo_t *cr) { cairo_stroke_preserve (cr); cairo_new_path (cr); } /** * cairo_stroke_preserve: * @cr: a cairo context * * A drawing operator that strokes the current path according to the * current line width, line join, line cap, and dash settings. Unlike * cairo_stroke(), cairo_stroke_preserve preserves the path within the * cairo context. * * See cairo_set_line_width(), cairo_set_line_join(), * cairo_set_line_cap(), cairo_set_dash(), and * cairo_stroke_preserve(). **/ void cairo_stroke_preserve (cairo_t *cr) { if (cr->status) return; cr->status = _cairo_gstate_stroke (cr->gstate, &cr->path); if (cr->status) _cairo_set_error (cr, cr->status); } slim_hidden_def(cairo_stroke_preserve); /** * cairo_fill: * @cr: a cairo context * * A drawing operator that fills the current path according to the * current fill rule, (each sub-path is implicitly closed before being * filled). After cairo_fill, the current path will be cleared from * the cairo context. See cairo_set_fill_rule() and * cairo_fill_preserve(). **/ void cairo_fill (cairo_t *cr) { cairo_fill_preserve (cr); cairo_new_path (cr); } /** * cairo_fill_preserve: * @cr: a cairo context * * A drawing operator that fills the current path according to the * current fill rule, (each sub-path is implicitly closed before being * filled). Unlike cairo_fill(), cairo_fill_preserve preserves the * path within the cairo context. * * See cairo_set_fill_rule() and cairo_fill(). **/ void cairo_fill_preserve (cairo_t *cr) { if (cr->status) return; cr->status = _cairo_gstate_fill (cr->gstate, &cr->path); if (cr->status) _cairo_set_error (cr, cr->status); } slim_hidden_def(cairo_fill_preserve); void cairo_copy_page (cairo_t *cr) { if (cr->status) return; cr->status = _cairo_gstate_copy_page (cr->gstate); if (cr->status) _cairo_set_error (cr, cr->status); } void cairo_show_page (cairo_t *cr) { if (cr->status) return; cr->status = _cairo_gstate_show_page (cr->gstate); if (cr->status) _cairo_set_error (cr, cr->status); } cairo_bool_t cairo_in_stroke (cairo_t *cr, double x, double y) { int inside; if (cr->status) return 0; cr->status = _cairo_gstate_in_stroke (cr->gstate, &cr->path, x, y, &inside); if (cr->status) return 0; return inside; } cairo_bool_t cairo_in_fill (cairo_t *cr, double x, double y) { int inside; if (cr->status) return 0; cr->status = _cairo_gstate_in_fill (cr->gstate, &cr->path, x, y, &inside); if (cr->status) { _cairo_set_error (cr, cr->status); return 0; } return inside; } void cairo_stroke_extents (cairo_t *cr, double *x1, double *y1, double *x2, double *y2) { if (cr->status) return; cr->status = _cairo_gstate_stroke_extents (cr->gstate, &cr->path, x1, y1, x2, y2); if (cr->status) _cairo_set_error (cr, cr->status); } void cairo_fill_extents (cairo_t *cr, double *x1, double *y1, double *x2, double *y2) { if (cr->status) return; cr->status = _cairo_gstate_fill_extents (cr->gstate, &cr->path, x1, y1, x2, y2); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_clip: * @cr: a cairo context * * Establishes a new clip region by intersecting the current clip * region with the current path as it would be filled by cairo_fill() * and according to the current fill rule (see cairo_set_fill_rule()). * * After cairo_clip, the current path will be cleared from the cairo * context. * * The current clip region affects all drawing operations by * effectively masking out any changes to the surface that are outside * the current clip region. * * Calling cairo_clip() can only make the clip region smaller, never * larger. But the current clip is part of the graphics state, so a * temporary restriction of the clip region can be achieved by * calling cairo_clip() within a cairo_save()/cairo_restore() * pair. The only other means of increasing the size of the clip * region is cairo_reset_clip(). **/ void cairo_clip (cairo_t *cr) { cairo_clip_preserve (cr); cairo_new_path (cr); } /** * cairo_clip_preserve: * @cr: a cairo context * * Establishes a new clip region by intersecting the current clip * region with the current path as it would be filled by cairo_fill() * and according to the current fill rule (see cairo_set_fill_rule()). * * Unlike cairo_clip(), cairo_clip_preserve preserves the path within * the cairo context. * * The current clip region affects all drawing operations by * effectively masking out any changes to the surface that are outside * the current clip region. * * Calling cairo_clip() can only make the clip region smaller, never * larger. But the current clip is part of the graphics state, so a * temporary restriction of the clip region can be achieved by * calling cairo_clip() within a cairo_save()/cairo_restore() * pair. The only other means of increasing the size of the clip * region is cairo_reset_clip(). **/ void cairo_clip_preserve (cairo_t *cr) { if (cr->status) return; cr->status = _cairo_gstate_clip (cr->gstate, &cr->path); if (cr->status) _cairo_set_error (cr, cr->status); } slim_hidden_def(cairo_clip_preserve); /** * cairo_reset_clip: * @cr: a cairo context * * Reset the current clip region to its original, unrestricted * state. That is, set the clip region to an infinitely large shape * containing the target surface. Equivalently, if infinity is too * hard to grasp, one can imagine the clip region being reset to the * exact bounds of the target surface. * * Note that code meant to be reusable should not call * cairo_reset_clip() as it will cause results unexpected by * higher-level code which calls cairo_clip(). Consider using * cairo_save() and cairo_restore() around cairo_clip() as a more * robust means of temporarily restricting the clip region. **/ void cairo_reset_clip (cairo_t *cr) { if (cr->status) return; cr->status = _cairo_gstate_reset_clip (cr->gstate); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_select_font_face: * @cr: a #cairo_t * @family: a font family name, encoded in UTF-8 * @slant: the slant for the font * @weight: the weight for the font * * Selects a family and style of font from a simplified description as * a family name, slant and weight. This function is meant to be used * only for applications with simple font needs: Cairo doesn't provide * for operations such as listing all available fonts on the system, * and it is expected that most applications will need to use a more * comprehensive font handling and text layout library in addition to * cairo. **/ void cairo_select_font_face (cairo_t *cr, const char *family, cairo_font_slant_t slant, cairo_font_weight_t weight) { if (cr->status) return; cr->status = _cairo_gstate_select_font_face (cr->gstate, family, slant, weight); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_get_font_face: * @cr: a #cairo_t * * Gets the current font face for a #cairo_t. * * Return value: the current font object. Can return %NULL * on out-of-memory or if the context is already in * an error state. This object is owned by cairo. To keep * a reference to it, you must call cairo_font_face_reference(). **/ cairo_font_face_t * cairo_get_font_face (cairo_t *cr) { cairo_font_face_t *font_face; if (cr->status) return (cairo_font_face_t*) &_cairo_font_face_nil; cr->status = _cairo_gstate_get_font_face (cr->gstate, &font_face); if (cr->status) { _cairo_set_error (cr, cr->status); return (cairo_font_face_t*) &_cairo_font_face_nil; } return font_face; } /** * cairo_font_extents: * @cr: a #cairo_t * @extents: a #cairo_font_extents_t object into which the results * will be stored. * * Gets the font extents for the currently selected font. **/ void cairo_font_extents (cairo_t *cr, cairo_font_extents_t *extents) { if (cr->status) return; cr->status = _cairo_gstate_get_font_extents (cr->gstate, extents); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_set_font_face: * @cr: a #cairo_t * @font_face: a #cairo_font_face_t, or %NULL to restore to the default font * * Replaces the current #cairo_font_face_t object in the #cairo_t with * @font_face. The replaced font face in the #cairo_t will be * destroyed if there are no other references to it. **/ void cairo_set_font_face (cairo_t *cr, cairo_font_face_t *font_face) { if (cr->status) return; cr->status = _cairo_gstate_set_font_face (cr->gstate, font_face); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_set_font_size: * @cr: a #cairo_t * @size: the new font size, in user space units * * Sets the current font matrix to a scale by a factor of @size, replacing * any font matrix previously set with cairo_set_font_size() or * cairo_set_font_matrix(). This results in a font size of @size user space * units. (More precisely, this matrix will result in the font's * em-square being a @size by @size square in user space.) **/ void cairo_set_font_size (cairo_t *cr, double size) { if (cr->status) return; cr->status = _cairo_gstate_set_font_size (cr->gstate, size); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_set_font_matrix * @cr: a #cairo_t * @matrix: a #cairo_matrix_t describing a transform to be applied to * the current font. * * Sets the current font matrix to @matrix. The font matrix gives a * transformation from the design space of the font (in this space, * the em-square is 1 unit by 1 unit) to user space. Normally, a * simple scale is used (see cairo_set_font_size()), but a more * complex font matrix can be used to shear the font * or stretch it unequally along the two axes **/ void cairo_set_font_matrix (cairo_t *cr, const cairo_matrix_t *matrix) { if (cr->status) return; cr->status = _cairo_gstate_set_font_matrix (cr->gstate, matrix); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_get_font_matrix * @cr: a #cairo_t * @matrix: return value for the matrix * * Stores the current font matrix into @matrix. See * cairo_set_font_matrix(). **/ void cairo_get_font_matrix (cairo_t *cr, cairo_matrix_t *matrix) { _cairo_gstate_get_font_matrix (cr->gstate, matrix); } /** * cairo_set_font_options: * @cr: a #cairo_t * @options: font options to use * * Sets a set of custom font rendering options for the #cairo_t. * Rendering options are derived by merging these options with the * options derived from underlying surface; if the value in @options * has a default value (like %CAIRO_ANTIALIAS_DEFAULT), then the value * from the surface is used. **/ void cairo_set_font_options (cairo_t *cr, const cairo_font_options_t *options) { if (cr->status) return; cr->status = _cairo_gstate_set_font_options (cr->gstate, options); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_get_font_options: * @cr: a #cairo_t * @options: a #cairo_font_options_t object into which to store * the retrieved options. All existing values are overwritten * * Retrieves font rendering options set via #cairo_set_font_options. * Note that the returned options do not include any options derived * from the underlying surface; they are literally the options * passed to cairo_set_font_options(). **/ void cairo_get_font_options (cairo_t *cr, cairo_font_options_t *options) { _cairo_gstate_get_font_options (cr->gstate, options); } /** * cairo_text_extents: * @cr: a #cairo_t * @utf8: a string of text, encoded in UTF-8 * @extents: a #cairo_text_extents_t object into which the results * will be stored * * Gets the extents for a string of text. The extents describe a * user-space rectangle that encloses the "inked" portion of the text, * (as it would be drawn by cairo_show_text()). Additionally, the * x_advance and y_advance values indicate the amount by which the * current point would be advanced by cairo_show_text(). * * Note that whitespace characters do not directly contribute to the * size of the rectangle (extents.width and extents.height). They do * contribute indirectly by changing the position of non-whitespace * characters. In particular, trailing whitespace characters are * likely to not affect the size of the rectangle, though they will * affect the x_advance and y_advance values. **/ void cairo_text_extents (cairo_t *cr, const char *utf8, cairo_text_extents_t *extents) { cairo_glyph_t *glyphs = NULL; int num_glyphs; double x, y; if (cr->status) return; if (utf8 == NULL) { extents->x_bearing = 0.0; extents->y_bearing = 0.0; extents->width = 0.0; extents->height = 0.0; extents->x_advance = 0.0; extents->y_advance = 0.0; return; } cairo_get_current_point (cr, &x, &y); cr->status = _cairo_gstate_text_to_glyphs (cr->gstate, utf8, x, y, &glyphs, &num_glyphs); if (cr->status) { if (glyphs) free (glyphs); _cairo_set_error (cr, cr->status); return; } cr->status = _cairo_gstate_glyph_extents (cr->gstate, glyphs, num_glyphs, extents); if (glyphs) free (glyphs); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_glyph_extents: * @cr: a #cairo_t * @glyphs: an array of #cairo_glyph_t objects * @num_glyphs: the number of elements in @glyphs * @extents: a #cairo_text_extents_t object into which the results * will be stored * * Gets the extents for an array of glyphs. The extents describe a * user-space rectangle that encloses the "inked" portion of the * glyphs, (as they would be drawn by cairo_show_glyphs()). * Additionally, the x_advance and y_advance values indicate the * amount by which the current point would be advanced by * cairo_show_glyphs. * * Note that whitespace glyphs do not contribute to the size of the * rectangle (extents.width and extents.height). **/ void cairo_glyph_extents (cairo_t *cr, cairo_glyph_t *glyphs, int num_glyphs, cairo_text_extents_t *extents) { if (cr->status) return; cr->status = _cairo_gstate_glyph_extents (cr->gstate, glyphs, num_glyphs, extents); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_show_text: * @cr: a cairo context * @utf8: a string of text encoded in UTF-8 * * A drawing operator that generates the shape from a string of UTF-8 * characters, rendered according to the current font_face, font_size * (font_matrix), and font_options. * * This function first computes a set of glyphs for the string of * text. The first glyph is placed so that its origin is at the * current point. The origin of each subsequent glyph is offset from * that of the previous glyph by the advance values of the previous * glyph. * * After this call the current point is moved to the origin of where * the next glyph would be placed in this same progression. That is, * the current point will be at the origin of the final glyph offset * by its advance values. This allows for easy display of a single * logical string with multiple calls to cairo_show_text(). * * NOTE: The cairo_show_text() function call is part of what the cairo * designers call the "toy" text API. It is convenient for short demos * and simple programs, but it is not expected to be adequate for the * most serious of text-using applications. See cairo_show_glyphs() * for the "real" text display API in cairo. **/ void cairo_show_text (cairo_t *cr, const char *utf8) { cairo_text_extents_t extents; cairo_glyph_t *glyphs = NULL, *last_glyph; int num_glyphs; double x, y; if (cr->status) return; if (utf8 == NULL) return; cairo_get_current_point (cr, &x, &y); cr->status = _cairo_gstate_text_to_glyphs (cr->gstate, utf8, x, y, &glyphs, &num_glyphs); if (cr->status) goto BAIL; if (num_glyphs == 0) return; cr->status = _cairo_gstate_show_glyphs (cr->gstate, glyphs, num_glyphs); if (cr->status) goto BAIL; last_glyph = &glyphs[num_glyphs - 1]; cr->status = _cairo_gstate_glyph_extents (cr->gstate, last_glyph, 1, &extents); if (cr->status) goto BAIL; x = last_glyph->x + extents.x_advance; y = last_glyph->y + extents.y_advance; cairo_move_to (cr, x, y); BAIL: if (glyphs) free (glyphs); if (cr->status) _cairo_set_error (cr, cr->status); } void cairo_show_glyphs (cairo_t *cr, cairo_glyph_t *glyphs, int num_glyphs) { if (cr->status) return; if (num_glyphs == 0) return; cr->status = _cairo_gstate_show_glyphs (cr->gstate, glyphs, num_glyphs); if (cr->status) _cairo_set_error (cr, cr->status); } void cairo_text_path (cairo_t *cr, const char *utf8) { cairo_glyph_t *glyphs = NULL; int num_glyphs; double x, y; if (cr->status) return; cairo_get_current_point (cr, &x, &y); cr->status = _cairo_gstate_text_to_glyphs (cr->gstate, utf8, x, y, &glyphs, &num_glyphs); if (cr->status) { if (glyphs) free (glyphs); _cairo_set_error (cr, cr->status); return; } cr->status = _cairo_gstate_glyph_path (cr->gstate, glyphs, num_glyphs, &cr->path); if (glyphs) free (glyphs); if (cr->status) _cairo_set_error (cr, cr->status); } void cairo_glyph_path (cairo_t *cr, cairo_glyph_t *glyphs, int num_glyphs) { if (cr->status) return; cr->status = _cairo_gstate_glyph_path (cr->gstate, glyphs, num_glyphs, &cr->path); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_get_operator: * @cr: a cairo context * * Gets the current compositing operator for a cairo context. * * Return value: the current compositing operator. **/ cairo_operator_t cairo_get_operator (cairo_t *cr) { return _cairo_gstate_get_operator (cr->gstate); } /** * cairo_get_tolerance: * @cr: a cairo context * * Gets the current tolerance value, as set by cairo_set_tolerance(). * * Return value: the current tolerance value. **/ double cairo_get_tolerance (cairo_t *cr) { return _cairo_gstate_get_tolerance (cr->gstate); } /** * cairo_get_antialias: * @cr: a cairo context * * Gets the current shape antialiasing mode, as set by cairo_set_shape_antialias(). * * Return value: the current shape antialiasing mode. **/ cairo_antialias_t cairo_get_antialias (cairo_t *cr) { return _cairo_gstate_get_antialias (cr->gstate); } /** * cairo_get_current_point: * @cr: a cairo context * @x: return value for X coordinate of the current point * @y: return value for Y coordinate of the current point * * Gets the current point of the current path, which is * conceptually the final point reached by the path so far. * * The current point is returned in the user-space coordinate * system. If there is no defined current point then @x and @y will * both be set to 0.0. * * Most path construction functions alter the current point. See the * following for details on how they affect the current point: * * cairo_new_path(), cairo_move_to(), cairo_line_to(), * cairo_curve_to(), cairo_arc(), cairo_rel_move_to(), * cairo_rel_line_to(), cairo_rel_curve_to(), cairo_arc(), * cairo_text_path(), cairo_stroke_to_path() **/ void cairo_get_current_point (cairo_t *cr, double *x_ret, double *y_ret) { cairo_status_t status; cairo_fixed_t x_fixed, y_fixed; double x, y; status = _cairo_path_fixed_get_current_point (&cr->path, &x_fixed, &y_fixed); if (status == CAIRO_STATUS_NO_CURRENT_POINT) { x = 0.0; y = 0.0; } else { x = _cairo_fixed_to_double (x_fixed); y = _cairo_fixed_to_double (y_fixed); _cairo_gstate_backend_to_user (cr->gstate, &x, &y); } if (x_ret) *x_ret = x; if (y_ret) *y_ret = y; } slim_hidden_def(cairo_get_current_point); /** * cairo_get_fill_rule: * @cr: a cairo context * * Gets the current fill rule, as set by cairo_set_fill_rule(). * * Return value: the current fill rule. **/ cairo_fill_rule_t cairo_get_fill_rule (cairo_t *cr) { return _cairo_gstate_get_fill_rule (cr->gstate); } /** * cairo_get_line_width: * @cr: a cairo context * * Gets the current line width, as set by cairo_set_line_width(). * * Return value: the current line width, in user-space units. **/ double cairo_get_line_width (cairo_t *cr) { return _cairo_gstate_get_line_width (cr->gstate); } /** * cairo_get_line_cap: * @cr: a cairo context * * Gets the current line cap style, as set by cairo_set_line_cap(). * * Return value: the current line cap style. **/ cairo_line_cap_t cairo_get_line_cap (cairo_t *cr) { return _cairo_gstate_get_line_cap (cr->gstate); } /** * cairo_get_line_join: * @cr: a cairo context * * Gets the current line join style, as set by cairo_set_line_join(). * * Return value: the current line join style. **/ cairo_line_join_t cairo_get_line_join (cairo_t *cr) { return _cairo_gstate_get_line_join (cr->gstate); } /** * cairo_get_miter_limit: * @cr: a cairo context * * Gets the current miter limit, as set by cairo_set_miter_limit(). * * Return value: the current miter limit. **/ double cairo_get_miter_limit (cairo_t *cr) { return _cairo_gstate_get_miter_limit (cr->gstate); } /** * cairo_get_matrix: * @cr: a cairo context * @matrix: return value for the matrix * * Stores the current transformation matrix (CTM) into @matrix. **/ void cairo_get_matrix (cairo_t *cr, cairo_matrix_t *matrix) { _cairo_gstate_get_matrix (cr->gstate, matrix); } /** * cairo_get_target: * @cr: a cairo context * * Gets the target surface for the cairo context as passed to * cairo_create(). * * This function will always return a valid pointer, but the result * can be a "nil" surface if @cr is already in an error state, * (ie. cairo_status() <literal>!=</literal> %CAIRO_STATUS_SUCCESS). * A nil surface is indicated by cairo_surface_status() * <literal>!=</literal> %CAIRO_STATUS_SUCCESS. * * Return value: the target surface. This object is owned by cairo. To * keep a reference to it, you must call cairo_surface_reference(). **/ cairo_surface_t * cairo_get_target (cairo_t *cr) { if (cr->status) return (cairo_surface_t*) &_cairo_surface_nil; return _cairo_gstate_get_original_target (cr->gstate); } /** * cairo_get_group_target: * @cr: a cairo context * @dx: device offset x value from cr's original target * @dy: device offset y value from cr's original target * * Gets the target surface for the current transparency group * started by the last cairo_push_group() call on the cairo * context. The offset between this surface and the cairo * context's original target surface is also returned if * dx and/or dy are not NULL. * * This function may return NULL if there is no transparency * group on the target. * * Return value: the target group surface, or NULL if none. This * object is owned by cairo. To keep a reference to it, you must call * cairo_surface_reference(). **/ cairo_surface_t * cairo_get_group_target (cairo_t *cr, double *dx, double *dy) { cairo_surface_t *gsurf; if (cr->status) return (cairo_surface_t*) &_cairo_surface_nil; gsurf = _cairo_gstate_get_target (cr->gstate); if (!gsurf) return NULL; if (dx || dy) _cairo_gstate_get_target_offsets_from_original (cr->gstate, dx, dy); return gsurf; } /** * cairo_copy_path: * @cr: a cairo context * * Creates a copy of the current path and returns it to the user as a * #cairo_path_t. See #cairo_path_data_t for hints on how to iterate * over the returned data structure. * * This function will always return a valid pointer, but the result * will have no data (<literal>data==NULL</literal> and * <literal>num_data==0</literal>), if either of the following * conditions hold: * * <orderedlist> * <listitem>If there is insufficient memory to copy the path.</listitem> * <listitem>If @cr is already in an error state.</listitem> * </orderedlist> * * In either case, <literal>path->status</literal> will be set to * %CAIRO_STATUS_NO_MEMORY (regardless of what the error status in * @cr might have been). * * Return value: the copy of the current path. The caller owns the * returned object and should call cairo_path_destroy() when finished * with it. **/ cairo_path_t * cairo_copy_path (cairo_t *cr) { if (cr->status) return (cairo_path_t*) &_cairo_path_nil; return _cairo_path_data_create (&cr->path, cr->gstate); } /** * cairo_has_clip * @cr: a cairo context * * Returns TRUE if the cairo context has any clipping active, otherwise * FALSE. */ cairo_bool_t cairo_has_clip (cairo_t *cr) { if (cr->status) return FALSE; return _cairo_gstate_has_clip (cr->gstate); } /** * cairo_extract_clip_rectangles * @cr: a cairo context * @max_rectangles: the maximum number of rectangles to be returned * @rectangles_out: the output buffer for the rectangles * @num_rectangles_out: the number of rectangles returned * * If the current clip can be expressed as the union of at most * 'max_rectangles' device-coordinate rectangles, then we fill in the array * with the rectangles, and return True. Otherwise we return False. When there * is no clipping active, we return False. */ cairo_bool_t cairo_extract_clip_rectangles (cairo_t *cr, int max_rectangles, cairo_clip_rect_t *rectangles_out, int *num_rectangles_out) { if (cr->status) return FALSE; return _cairo_gstate_extract_clip_rectangles (cr->gstate, max_rectangles, rectangles_out, num_rectangles_out); } /** * cairo_copy_path_flat: * @cr: a cairo context * * Gets a flattened copy of the current path and returns it to the * user as a #cairo_path_t. See #cairo_path_data_t for hints on * how to iterate over the returned data structure. * * This function is like cairo_copy_path() except that any curves * in the path will be approximated with piecewise-linear * approximations, (accurate to within the current tolerance * value). That is, the result is guaranteed to not have any elements * of type %CAIRO_PATH_CURVE_TO which will instead be replaced by a * series of %CAIRO_PATH_LINE_TO elements. * * This function will always return a valid pointer, but the result * will have no data (<literal>data==NULL</literal> and * <literal>num_data==0</literal>), if either of the following * conditions hold: * * <orderedlist> * <listitem>If there is insufficient memory to copy the path. In this * case <literal>path->status</literal> will be set to * %CAIRO_STATUS_NO_MEMORY.</listitem> * <listitem>If @cr is already in an error state. In this case * <literal>path->status</literal> will contain the same status that * would be returned by cairo_status().</listitem> * </orderedlist> * * Return value: the copy of the current path. The caller owns the * returned object and should call cairo_path_destroy() when finished * with it. **/ cairo_path_t * cairo_copy_path_flat (cairo_t *cr) { if (cr->status) return (cairo_path_t*) &_cairo_path_nil; else return _cairo_path_data_create_flat (&cr->path, cr->gstate); } /** * cairo_append_path: * @cr: a cairo context * @path: path to be appended * * Append the @path onto the current path. The @path may be either the * return value from one of cairo_copy_path() or * cairo_copy_path_flat() or it may be constructed manually. See * #cairo_path_t for details on how the path data structure should be * initialized, and note that <literal>path->status</literal> must be * initialized to %CAIRO_STATUS_SUCCESS. **/ void cairo_append_path (cairo_t *cr, cairo_path_t *path) { if (cr->status) return; if (path == NULL) { _cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER); return; } if (path->status) { if (path->status <= CAIRO_STATUS_LAST_STATUS) _cairo_set_error (cr, path->status); else _cairo_set_error (cr, CAIRO_STATUS_INVALID_STATUS); return; } if (path->data == NULL) { _cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER); return; } cr->status = _cairo_path_data_append_to_context (path, cr); if (cr->status) _cairo_set_error (cr, cr->status); } /** * cairo_status: * @cr: a cairo context * * Checks whether an error has previously occurred for this context. * * Returns the current status of this context, see #cairo_status_t **/ cairo_status_t cairo_status (cairo_t *cr) { return cr->status; } /** * cairo_status_to_string: * @status: a cairo status * * Provides a human-readable description of a #cairo_status_t. * * Returns a string representation of the status */ const char * cairo_status_to_string (cairo_status_t status) { switch (status) { case CAIRO_STATUS_SUCCESS: return "success"; case CAIRO_STATUS_NO_MEMORY: return "out of memory"; case CAIRO_STATUS_INVALID_RESTORE: return "cairo_restore without matching cairo_save"; case CAIRO_STATUS_INVALID_POP_GROUP: return "cairo_pop_group without matching cairo_push_group"; case CAIRO_STATUS_NO_CURRENT_POINT: return "no current point defined"; case CAIRO_STATUS_INVALID_MATRIX: return "invalid matrix (not invertible)"; case CAIRO_STATUS_INVALID_STATUS: return "invalid value for an input cairo_status_t"; case CAIRO_STATUS_NULL_POINTER: return "NULL pointer"; case CAIRO_STATUS_INVALID_STRING: return "input string not valid UTF-8"; case CAIRO_STATUS_INVALID_PATH_DATA: return "input path data not valid"; case CAIRO_STATUS_READ_ERROR: return "error while reading from input stream"; case CAIRO_STATUS_WRITE_ERROR: return "error while writing to output stream"; case CAIRO_STATUS_SURFACE_FINISHED: return "the target surface has been finished"; case CAIRO_STATUS_SURFACE_TYPE_MISMATCH: return "the surface type is not appropriate for the operation"; case CAIRO_STATUS_PATTERN_TYPE_MISMATCH: return "the pattern type is not appropriate for the operation"; case CAIRO_STATUS_INVALID_CONTENT: return "invalid value for an input cairo_content_t"; case CAIRO_STATUS_INVALID_FORMAT: return "invalid value for an input cairo_format_t"; case CAIRO_STATUS_INVALID_VISUAL: return "invalid value for an input Visual*"; case CAIRO_STATUS_FILE_NOT_FOUND: return "file not found"; case CAIRO_STATUS_INVALID_DASH: return "invalid value for a dash setting"; } return "<unknown error status>"; } void _cairo_restrict_value (double *value, double min, double max) { if (*value < min) *value = min; else if (*value > max) *value = max; }