linear-gradient-subset.c [plain text]
#include "cairo-test.h"
#include "stdio.h"
static const double gradient_angles[] = { 0, 45, 90 };
#define N_GRADIENT_ANGLES 3
static const double rotate_angles[] = { 0, 45, 90 };
#define N_ROTATE_ANGLES 3
static const int n_stops[] = { 2, 3 };
#define N_N_STOPS 2
#define UNIT_SIZE 6
#define UNIT_SIZE 6
#define PAD 1
#define WIDTH N_GRADIENT_ANGLES * UNIT_SIZE + (N_GRADIENT_ANGLES + 1) * PAD
#define HEIGHT N_N_STOPS * N_ROTATE_ANGLES * UNIT_SIZE + (N_N_STOPS * N_ROTATE_ANGLES + 1) * PAD
static void
draw_unit (cairo_t *cr,
double gradient_angle,
double rotate_angle,
int n_stops)
{
cairo_pattern_t *pattern;
cairo_rectangle (cr, 0, 0, 1, 1);
cairo_clip (cr);
cairo_new_path(cr);
cairo_set_source_rgb (cr, 0.0, 0.0, 0.0);
cairo_rectangle (cr, 0, 0, 1, 1);
cairo_fill (cr);
cairo_translate (cr, 0.5, 0.5);
cairo_scale (cr, 1 / 1.5, 1 / 1.5);
cairo_rotate (cr, rotate_angle);
pattern = cairo_pattern_create_linear (-0.5 * cos (gradient_angle), -0.5 * sin (gradient_angle),
0.5 * cos (gradient_angle), 0.5 * sin (gradient_angle));
if (n_stops == 2) {
cairo_pattern_add_color_stop_rgb (pattern, 0.2, 0.3, 0.3, 0.3);
cairo_pattern_add_color_stop_rgb (pattern, 0.8, 1.0, 1.0, 1.0);
} else {
cairo_pattern_add_color_stop_rgb (pattern, 0.2, 1.0, 0.0, 0.0);
cairo_pattern_add_color_stop_rgb (pattern, 0.5, 1.0, 1.0, 1.0);
cairo_pattern_add_color_stop_rgb (pattern, 0.8, 0.0, 0.0, 1.0);
}
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
cairo_rectangle (cr, -0.5, -0.5, 1, 1);
cairo_fill (cr);
}
static cairo_test_status_t
draw (cairo_t *cr, int width, int height)
{
int i, j, k;
cairo_set_source_rgb (cr, 0.5, 0.5, 0.5);
cairo_paint (cr);
for (i = 0; i < N_GRADIENT_ANGLES; i++)
for (j = 0; j < N_ROTATE_ANGLES; j++)
for (k = 0; k < N_N_STOPS; k++) {
cairo_save (cr);
cairo_translate (cr,
PAD + (PAD + UNIT_SIZE) * i,
PAD + (PAD + UNIT_SIZE) * (N_ROTATE_ANGLES * k + j));
cairo_scale (cr, UNIT_SIZE, UNIT_SIZE);
draw_unit (cr,
gradient_angles[i] * M_PI / 180.,
rotate_angles[j] * M_PI / 180.,
n_stops[k]);
cairo_restore (cr);
}
return CAIRO_TEST_SUCCESS;
}
CAIRO_TEST (linear_gradient_subset,
"Tests the drawing of linear gradients",
"gradient",
NULL,
WIDTH, HEIGHT,
NULL, draw)