mutter/tests/conform/test-cogl-readpixels.c
Neil Roberts c0a553163b cogl: Support any format in cogl_read_pixels
cogl_read_pixels() no longer asserts that the format passed in is
RGBA_8888 but instead accepts any format. The appropriate GL enums for
the format are passed to glReadPixels so OpenGL should be perform a
conversion if neccessary.

It currently assumes glReadPixels will always give us premultiplied
data. This will usually be correct because the result of the default
blending operations for Cogl ends up with premultiplied data in the
framebuffer. However it is possible for the framebuffer to be in
whatever format depending on what CoglMaterial is used to render to
it. Eventually we may want to add a way for an application to inform
Cogl that the framebuffer is not premultiplied in case it is being
used for some special purpose.

If the requested format is not premultiplied then Cogl will convert
it. The tests have been changed to read the data as premultiplied so
that they won't be affected by the conversion. Picking in Clutter has
been changed to use COGL_PIXEL_FORMAT_RGB_888 because it doesn't need
the alpha component. clutter_stage_read_pixels is left unchanged
because the application can't specify a format for that so it seems to
make most sense to store unpremultiplied values.

http://bugzilla.openedhand.com/show_bug.cgi?id=1959
2010-03-02 11:01:35 +00:00

172 lines
5.3 KiB
C

#include <clutter/clutter.h>
#include <cogl/cogl.h>
#include "test-conform-common.h"
#define RED 0
#define GREEN 1
#define BLUE 2
#define FRAMEBUFFER_WIDTH 640
#define FRAMEBUFFER_HEIGHT 480
static const ClutterColor stage_color = { 0x0, 0x0, 0x0, 0xff };
static void
on_paint (ClutterActor *actor, void *state)
{
float saved_viewport[4];
CoglMatrix saved_projection;
CoglMatrix projection;
CoglMatrix modelview;
guchar *data;
CoglHandle tex;
CoglHandle offscreen;
guint32 *pixels;
guint8 *pixelsc;
/* Save the Clutter viewport/matrices and load identity matrices */
cogl_get_viewport (saved_viewport);
cogl_get_projection_matrix (&saved_projection);
cogl_push_matrix ();
cogl_matrix_init_identity (&projection);
cogl_matrix_init_identity (&modelview);
cogl_set_projection_matrix (&projection);
cogl_set_modelview_matrix (&modelview);
/* All offscreen rendering is done upside down so the first thing we
* verify is reading back grid of colors from a CoglOffscreen framebuffer
*/
data = g_malloc (FRAMEBUFFER_WIDTH * 4 * FRAMEBUFFER_HEIGHT);
tex = cogl_texture_new_from_data (FRAMEBUFFER_WIDTH, FRAMEBUFFER_HEIGHT,
COGL_TEXTURE_NO_SLICING,
COGL_PIXEL_FORMAT_RGBA_8888, /* data fmt */
COGL_PIXEL_FORMAT_ANY, /* internal fmt */
FRAMEBUFFER_WIDTH * 4, /* rowstride */
data);
g_free (data);
offscreen = cogl_offscreen_new_to_texture (tex);
cogl_push_framebuffer (offscreen);
/* red, top left */
cogl_set_source_color4ub (0xff, 0x00, 0x00, 0xff);
cogl_rectangle (-1, 1, 0, 0);
/* green, top right */
cogl_set_source_color4ub (0x00, 0xff, 0x00, 0xff);
cogl_rectangle (0, 1, 1, 0);
/* blue, bottom left */
cogl_set_source_color4ub (0x00, 0x00, 0xff, 0xff);
cogl_rectangle (-1, 0, 0, -1);
/* white, bottom right */
cogl_set_source_color4ub (0xff, 0xff, 0xff, 0xff);
cogl_rectangle (0, 0, 1, -1);
pixels = g_malloc0 (FRAMEBUFFER_WIDTH * 4 * FRAMEBUFFER_HEIGHT);
cogl_read_pixels (0, 0, FRAMEBUFFER_WIDTH, FRAMEBUFFER_HEIGHT,
COGL_READ_PIXELS_COLOR_BUFFER,
COGL_PIXEL_FORMAT_RGBA_8888_PRE,
(guchar *)pixels);
g_assert_cmpint (pixels[0], ==, 0xff0000ff);
g_assert_cmpint (pixels[FRAMEBUFFER_WIDTH - 1], ==, 0xff00ff00);
g_assert_cmpint (pixels[(FRAMEBUFFER_HEIGHT - 1) * FRAMEBUFFER_WIDTH], ==, 0xffff0000);
g_assert_cmpint (pixels[(FRAMEBUFFER_HEIGHT - 1) * FRAMEBUFFER_WIDTH + FRAMEBUFFER_WIDTH - 1], ==, 0xffffffff);
g_free (pixels);
cogl_pop_framebuffer ();
cogl_handle_unref (offscreen);
/* Now verify reading back from an onscreen framebuffer...
*/
cogl_set_source_texture (tex);
cogl_rectangle (-1, 1, 1, -1);
pixels = g_malloc0 (FRAMEBUFFER_WIDTH * 4 * FRAMEBUFFER_HEIGHT);
cogl_read_pixels (0, 0, FRAMEBUFFER_WIDTH, FRAMEBUFFER_HEIGHT,
COGL_READ_PIXELS_COLOR_BUFFER,
COGL_PIXEL_FORMAT_RGBA_8888_PRE,
(guchar *)pixels);
g_assert_cmpint (pixels[0], ==, 0xff0000ff);
g_assert_cmpint (pixels[FRAMEBUFFER_WIDTH - 1], ==, 0xff00ff00);
g_assert_cmpint (pixels[(FRAMEBUFFER_HEIGHT - 1) * FRAMEBUFFER_WIDTH], ==, 0xffff0000);
g_assert_cmpint (pixels[(FRAMEBUFFER_HEIGHT - 1) * FRAMEBUFFER_WIDTH + FRAMEBUFFER_WIDTH - 1], ==, 0xffffffff);
g_free (pixels);
/* Verify using BGR format */
cogl_set_source_texture (tex);
cogl_rectangle (-1, 1, 1, -1);
pixelsc = g_malloc0 (FRAMEBUFFER_WIDTH * 3 * FRAMEBUFFER_HEIGHT);
cogl_read_pixels (0, 0, FRAMEBUFFER_WIDTH, FRAMEBUFFER_HEIGHT,
COGL_READ_PIXELS_COLOR_BUFFER,
COGL_PIXEL_FORMAT_BGR_888,
(guchar *)pixelsc);
g_assert_cmpint (pixelsc[0], ==, 0x00);
g_assert_cmpint (pixelsc[1], ==, 0x00);
g_assert_cmpint (pixelsc[2], ==, 0xff);
g_assert_cmpint (pixelsc[(FRAMEBUFFER_WIDTH - 1) * 3 + 0], ==, 0x00);
g_assert_cmpint (pixelsc[(FRAMEBUFFER_WIDTH - 1) * 3 + 1], ==, 0xff);
g_assert_cmpint (pixelsc[(FRAMEBUFFER_WIDTH - 1) * 3 + 2], ==, 0x00);
g_free (pixelsc);
cogl_handle_unref (tex);
/* Comment this out if you want visual feedback of what this test
* paints.
*/
clutter_main_quit ();
}
static gboolean
queue_redraw (gpointer stage)
{
clutter_actor_queue_redraw (CLUTTER_ACTOR (stage));
return TRUE;
}
void
test_cogl_readpixels (TestConformSimpleFixture *fixture,
gconstpointer data)
{
guint idle_source;
ClutterActor *stage;
stage = clutter_stage_get_default ();
clutter_stage_set_color (CLUTTER_STAGE (stage), &stage_color);
/* We force continuous redrawing of the stage, since we need to skip
* the first few frames, and we wont be doing anything else that
* will trigger redrawing. */
idle_source = g_idle_add (queue_redraw, stage);
g_signal_connect_after (stage, "paint", G_CALLBACK (on_paint), NULL);
clutter_actor_show (stage);
clutter_main ();
g_source_remove (idle_source);
/* Remove all of the actors from the stage */
clutter_container_foreach (CLUTTER_CONTAINER (stage),
(ClutterCallback) clutter_actor_destroy,
NULL);
if (g_test_verbose ())
g_print ("OK\n");
}