cairo-wgl-context.c [plain text]
#include "cairoint.h"
#include "cairo-gl-private.h"
#include "cairo-error-private.h"
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
typedef struct _cairo_wgl_context {
cairo_gl_context_t base;
HDC dummy_dc;
HWND dummy_wnd;
HGLRC rc;
HDC prev_dc;
HGLRC prev_rc;
} cairo_wgl_context_t;
typedef struct _cairo_wgl_surface {
cairo_gl_surface_t base;
HDC dc;
} cairo_wgl_surface_t;
static void
_wgl_acquire (void *abstract_ctx)
{
cairo_wgl_context_t *ctx = abstract_ctx;
HDC current_dc;
ctx->prev_dc = wglGetCurrentDC ();
ctx->prev_rc = wglGetCurrentContext ();
if (ctx->base.current_target == NULL ||
_cairo_gl_surface_is_texture (ctx->base.current_target))
{
current_dc = ctx->dummy_dc;
}
else
{
cairo_wgl_surface_t *surface = (cairo_wgl_surface_t *) ctx->base.current_target;
current_dc = surface->dc;
}
if (ctx->prev_dc != current_dc ||
(ctx->prev_rc != ctx->rc &&
current_dc != ctx->dummy_dc))
{
wglMakeCurrent (current_dc, ctx->rc);
}
}
static void
_wgl_make_current (void *abstract_ctx, cairo_gl_surface_t *abstract_surface)
{
cairo_wgl_context_t *ctx = abstract_ctx;
cairo_wgl_surface_t *surface = (cairo_wgl_surface_t *) abstract_surface;
wglMakeCurrent (surface->dc, ctx->rc);
}
static void
_wgl_release (void *abstract_ctx)
{
cairo_wgl_context_t *ctx = abstract_ctx;
if (ctx->prev_dc != wglGetCurrentDC () ||
ctx->prev_rc != wglGetCurrentContext ())
{
wglMakeCurrent (ctx->prev_dc,
ctx->prev_rc);
}
}
static void
_wgl_swap_buffers (void *abstract_ctx,
cairo_gl_surface_t *abstract_surface)
{
cairo_wgl_surface_t *surface = (cairo_wgl_surface_t *) abstract_surface;
SwapBuffers (surface->dc);
}
static void
_wgl_destroy (void *abstract_ctx)
{
cairo_wgl_context_t *ctx = abstract_ctx;
if (ctx->dummy_dc != 0) {
wglMakeCurrent (ctx->dummy_dc, 0);
ReleaseDC (ctx->dummy_wnd, ctx->dummy_dc);
DestroyWindow (ctx->dummy_wnd);
}
}
static cairo_status_t
_wgl_dummy_ctx (cairo_wgl_context_t *ctx)
{
WNDCLASSEXA wincl;
PIXELFORMATDESCRIPTOR pfd;
int format;
HDC dc;
ZeroMemory (&wincl, sizeof (WNDCLASSEXA));
wincl.cbSize = sizeof (WNDCLASSEXA);
wincl.hInstance = GetModuleHandle (0);
wincl.lpszClassName = "cairo_wgl_context_dummy";
wincl.lpfnWndProc = DefWindowProcA;
wincl.style = CS_OWNDC;
RegisterClassExA (&wincl);
ctx->dummy_wnd = CreateWindow ("cairo_wgl_context_dummy", 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
ctx->dummy_dc = GetDC (ctx->dummy_wnd);
ZeroMemory (&pfd, sizeof (PIXELFORMATDESCRIPTOR));
pfd.nSize = sizeof (PIXELFORMATDESCRIPTOR);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 24;
pfd.cDepthBits = 16;
pfd.iLayerType = PFD_MAIN_PLANE;
format = ChoosePixelFormat (ctx->dummy_dc, &pfd);
SetPixelFormat (ctx->dummy_dc, format, &pfd);
wglMakeCurrent(ctx->dummy_dc, ctx->rc);
return CAIRO_STATUS_SUCCESS;
}
cairo_device_t *
cairo_wgl_device_create (HGLRC rc)
{
cairo_wgl_context_t *ctx;
cairo_status_t status;
ctx = calloc (1, sizeof (cairo_wgl_context_t));
if (unlikely (ctx == NULL))
return _cairo_gl_context_create_in_error (CAIRO_STATUS_NO_MEMORY);
ctx->rc = rc;
ctx->prev_dc = 0;
ctx->prev_rc = 0;
status = _wgl_dummy_ctx (ctx);
if (unlikely (status)) {
free (ctx);
return _cairo_gl_context_create_in_error (status);
}
ctx->base.acquire = _wgl_acquire;
ctx->base.release = _wgl_release;
ctx->base.make_current = _wgl_make_current;
ctx->base.swap_buffers = _wgl_swap_buffers;
ctx->base.destroy = _wgl_destroy;
status = _cairo_gl_context_init (&ctx->base);
if (unlikely (status)) {
free (ctx);
return _cairo_gl_context_create_in_error (status);
}
ctx->base.release (ctx);
return &ctx->base.base;
}
HGLRC
cairo_wgl_device_get_context (cairo_device_t *device)
{
cairo_wgl_context_t *ctx;
if (device->backend->type != CAIRO_DEVICE_TYPE_GL) {
_cairo_error_throw (CAIRO_STATUS_DEVICE_TYPE_MISMATCH);
return NULL;
}
ctx = (cairo_wgl_context_t *) device;
return ctx->rc;
}
cairo_surface_t *
cairo_gl_surface_create_for_dc (cairo_device_t *device,
HDC dc,
int width,
int height)
{
cairo_wgl_surface_t *surface;
if (unlikely (device->status))
return _cairo_surface_create_in_error (device->status);
if (device->backend->type != CAIRO_DEVICE_TYPE_GL)
return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_SURFACE_TYPE_MISMATCH));
surface = calloc (1, sizeof (cairo_wgl_surface_t));
if (unlikely (surface == NULL))
return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
_cairo_gl_surface_init (device, &surface->base,
CAIRO_CONTENT_COLOR_ALPHA, width, height);
surface->dc = dc;
return &surface->base.base;
}