mingw-cairo/SOURCES/0001-win32-Add-cairo-API-to-set-up-a-Win32-surface-for-an.patch
2021-09-09 22:14:12 +00:00

144 lines
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Diff

From 16898ba11b4d6e9e2e64bb2d02d0fb5adbe266e2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=A0=D1=83=D1=81=D0=BB=D0=B0=D0=BD=20=D0=98=D0=B6=D0=B1?=
=?UTF-8?q?=D1=83=D0=BB=D0=B0=D1=82=D0=BE=D0=B2?= <lrn1986@gmail.com>
Date: Thu, 26 Mar 2015 19:33:43 +0000
Subject: [PATCH 1/2] win32: Add cairo API to set up a Win32 surface for an HDC
with an alpha channel.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Signed-off-by: Руслан Ижбулатов <lrn1986@gmail.com>
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>
---
src/cairo-win32.h | 4 ++
src/win32/cairo-win32-display-surface.c | 68 +++++++++++++++++++++++++--------
2 files changed, 56 insertions(+), 16 deletions(-)
diff --git a/src/cairo-win32.h b/src/cairo-win32.h
index 3d2e1c6..db4cac6 100644
--- a/src/cairo-win32.h
+++ b/src/cairo-win32.h
@@ -49,6 +49,10 @@ cairo_public cairo_surface_t *
cairo_win32_surface_create (HDC hdc);
cairo_public cairo_surface_t *
+cairo_win32_surface_create_with_format (HDC hdc,
+ cairo_format_t format);
+
+cairo_public cairo_surface_t *
cairo_win32_printing_surface_create (HDC hdc);
cairo_public cairo_surface_t *
diff --git a/src/win32/cairo-win32-display-surface.c b/src/win32/cairo-win32-display-surface.c
index 965f2c4..1571480 100644
--- a/src/win32/cairo-win32-display-surface.c
+++ b/src/win32/cairo-win32-display-surface.c
@@ -917,31 +917,41 @@ static const cairo_surface_backend_t cairo_win32_display_surface_backend = {
*/
/**
- * cairo_win32_surface_create:
+ * cairo_win32_surface_create_with_format:
* @hdc: the DC to create a surface for
+ * @format: format of pixels in the surface to create
*
* Creates a cairo surface that targets the given DC. The DC will be
* queried for its initial clip extents, and this will be used as the
- * size of the cairo surface. The resulting surface will always be of
- * format %CAIRO_FORMAT_RGB24; should you need another surface format,
- * you will need to create one through
- * cairo_win32_surface_create_with_dib().
+ * size of the cairo surface.
*
- * Return value: the newly created surface
+ * Supported formats are:
+ * %CAIRO_FORMAT_ARGB32
+ * %CAIRO_FORMAT_RGB24
*
- * Since: 1.0
+ * Note: @format only tells cairo how to draw on the surface, not what
+ * the format of the surface is. Namely, cairo does not (and cannot)
+ * check that @hdc actually supports alpha-transparency.
+ *
+ * Return value: the newly created surface, NULL on failure
+ *
+ * Since: 1.14.3
**/
cairo_surface_t *
-cairo_win32_surface_create (HDC hdc)
+cairo_win32_surface_create_with_format (HDC hdc, cairo_format_t format)
{
cairo_win32_display_surface_t *surface;
- cairo_format_t format;
cairo_status_t status;
cairo_device_t *device;
- /* Assume that everything coming in as a HDC is RGB24 */
- format = CAIRO_FORMAT_RGB24;
+ switch (format) {
+ default:
+ return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_INVALID_FORMAT));
+ case CAIRO_FORMAT_ARGB32:
+ case CAIRO_FORMAT_RGB24:
+ break;
+ }
surface = malloc (sizeof (*surface));
if (surface == NULL)
@@ -977,6 +987,28 @@ cairo_win32_surface_create (HDC hdc)
}
/**
+ * cairo_win32_surface_create:
+ * @hdc: the DC to create a surface for
+ *
+ * Creates a cairo surface that targets the given DC. The DC will be
+ * queried for its initial clip extents, and this will be used as the
+ * size of the cairo surface. The resulting surface will always be of
+ * format %CAIRO_FORMAT_RGB24; should you need another surface format,
+ * you will need to create one through
+ * cairo_win32_surface_create_with_format() or
+ * cairo_win32_surface_create_with_dib().
+ *
+ * Return value: the newly created surface, NULL on failure
+ *
+ * Since: 1.0
+ **/
+cairo_surface_t *
+cairo_win32_surface_create (HDC hdc)
+{
+ return cairo_win32_surface_create_with_format (hdc, CAIRO_FORMAT_RGB24);
+}
+
+/**
* cairo_win32_surface_create_with_dib:
* @format: format of pixels in the surface to create
* @width: width of the surface, in pixels
@@ -1027,12 +1059,16 @@ cairo_win32_surface_create_with_ddb (HDC hdc,
HDC screen_dc, ddb_dc;
HBITMAP saved_dc_bitmap;
- if (format != CAIRO_FORMAT_RGB24)
+ switch (format) {
+ default:
+/* XXX handle these eventually */
+ case CAIRO_FORMAT_A8:
+ case CAIRO_FORMAT_A1:
return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_INVALID_FORMAT));
-/* XXX handle these eventually
- format != CAIRO_FORMAT_A8 ||
- format != CAIRO_FORMAT_A1)
-*/
+ case CAIRO_FORMAT_ARGB32:
+ case CAIRO_FORMAT_RGB24:
+ break;
+ }
if (!hdc) {
screen_dc = GetDC (NULL);
--
2.4.3