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mutter-performance-source/tests/conform/test-cogl-backface-culling.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

339 lines
9.7 KiB
C

#include <clutter/clutter.h>
#include <cogl/cogl.h>
#include <string.h>
#include "test-conform-common.h"
#ifdef CLUTTER_COGL_HAS_GL
/* Size the texture so that it is just off a power of two to enourage
it so use software tiling when NPOTs aren't available */
#define TEXTURE_SIZE 257
#else /* CLUTTER_COGL_HAS_GL */
/* We can't use the funny-sized texture on GL ES because it will break
cogl_texture_polygon. However there is only one code path for
rendering quads so there is no need */
#define TEXTURE_SIZE 32
#endif /* CLUTTER_COGL_HAS_GL */
/* Amount of pixels to skip off the top, bottom, left and right of the
texture when reading back the stage */
#define TEST_INSET 4
/* Size to actually render the texture at */
#define TEXTURE_RENDER_SIZE 32
typedef struct _TestState
{
CoglHandle texture;
CoglHandle offscreen;
CoglHandle offscreen_tex;
} TestState;
static gboolean
validate_part (int xnum, int ynum, gboolean shown)
{
guchar *pixels, *p;
gboolean ret = TRUE;
pixels = g_malloc0 ((TEXTURE_RENDER_SIZE - TEST_INSET * 2)
* (TEXTURE_RENDER_SIZE - TEST_INSET * 2) * 4);
/* Read the appropriate part but skip out a few pixels around the
edges */
cogl_read_pixels (xnum * TEXTURE_RENDER_SIZE + TEST_INSET,
ynum * TEXTURE_RENDER_SIZE + TEST_INSET,
TEXTURE_RENDER_SIZE - TEST_INSET * 2,
TEXTURE_RENDER_SIZE - TEST_INSET * 2,
COGL_READ_PIXELS_COLOR_BUFFER,
COGL_PIXEL_FORMAT_RGBA_8888_PRE,
pixels);
/* Make sure every pixels is the appropriate color */
for (p = pixels;
p < pixels + ((TEXTURE_RENDER_SIZE - TEST_INSET * 2)
* (TEXTURE_RENDER_SIZE - TEST_INSET * 2));
p += 4)
{
if (p[0] != (shown ? 255 : 0))
ret = FALSE;
if (p[1] != 0)
ret = FALSE;
if (p[2] != 0)
ret = FALSE;
}
g_free (pixels);
return ret;
}
static void
do_test_backface_culling (TestState *state)
{
int i;
CoglHandle material = cogl_material_new ();
cogl_material_set_layer_filters (material, 0,
COGL_MATERIAL_FILTER_NEAREST,
COGL_MATERIAL_FILTER_NEAREST);
cogl_set_backface_culling_enabled (TRUE);
cogl_push_matrix ();
/* Render the scene twice - once with backface culling enabled and
once without. The second time is translated so that it is below
the first */
for (i = 0; i < 2; i++)
{
float x1 = 0, x2, y1 = 0, y2 = (float)(TEXTURE_RENDER_SIZE);
CoglTextureVertex verts[4];
cogl_set_source (material);
memset (verts, 0, sizeof (verts));
x2 = x1 + (float)(TEXTURE_RENDER_SIZE);
/* Draw a front-facing texture */
cogl_material_set_layer (material, 0, state->texture);
cogl_rectangle (x1, y1, x2, y2);
x1 = x2;
x2 = x1 + (float)(TEXTURE_RENDER_SIZE);
/* Draw a front-facing texture with flipped texcoords */
cogl_material_set_layer (material, 0, state->texture);
cogl_rectangle_with_texture_coords (x1, y1, x2, y2,
1.0, 0.0, 0.0, 1.0);
x1 = x2;
x2 = x1 + (float)(TEXTURE_RENDER_SIZE);
/* Draw a back-facing texture */
cogl_material_set_layer (material, 0, state->texture);
cogl_rectangle (x2, y1, x1, y2);
x1 = x2;
x2 = x1 + (float)(TEXTURE_RENDER_SIZE);
/* Draw a front-facing texture polygon */
verts[0].x = x1; verts[0].y = y2;
verts[1].x = x2; verts[1].y = y2;
verts[2].x = x2; verts[2].y = y1;
verts[3].x = x1; verts[3].y = y1;
verts[0].tx = 0; verts[0].ty = 0;
verts[1].tx = 1.0; verts[1].ty = 0;
verts[2].tx = 1.0; verts[2].ty = 1.0;
verts[3].tx = 0; verts[3].ty = 1.0;
cogl_material_set_layer (material, 0, state->texture);
cogl_polygon (verts, 4, FALSE);
x1 = x2;
x2 = x1 + (float)(TEXTURE_RENDER_SIZE);
/* Draw a back-facing texture polygon */
verts[0].x = x1; verts[0].y = y1;
verts[1].x = x2; verts[1].y = y1;
verts[2].x = x2; verts[2].y = y2;
verts[3].x = x1; verts[3].y = y2;
verts[0].tx = 0; verts[0].ty = 0;
verts[1].tx = 1.0; verts[1].ty = 0;
verts[2].tx = 1.0; verts[2].ty = 1.0;
verts[3].tx = 0; verts[3].ty = 1.0;
cogl_material_set_layer (material, 0, state->texture);
cogl_polygon (verts, 4, FALSE);
x1 = x2;
x2 = x1 + (float)(TEXTURE_RENDER_SIZE);
/* Draw a regular rectangle (this should always show) */
cogl_set_source_color4f (1.0, 0, 0, 1.0);
cogl_rectangle (x1, y1, x2, y2);
/* The second time round draw beneath the first with backface
culling disabled */
cogl_translate (0, TEXTURE_RENDER_SIZE, 0);
cogl_set_backface_culling_enabled (FALSE);
}
cogl_handle_unref (material);
cogl_pop_matrix ();
/* Front-facing texture */
g_assert (validate_part (0, 0, TRUE));
/* Front-facing texture with flipped tex coords */
g_assert (validate_part (1, 0, TRUE));
/* Back-facing texture */
g_assert (validate_part (2, 0, FALSE));
/* Front-facing texture polygon */
g_assert (validate_part (3, 0, TRUE));
/* Back-facing texture polygon */
g_assert (validate_part (4, 0, FALSE));
/* Regular rectangle */
g_assert (validate_part (5, 0, TRUE));
/* Backface culling disabled - everything should be shown */
/* Front-facing texture */
g_assert (validate_part (0, 1, TRUE));
/* Front-facing texture with flipped tex coords */
g_assert (validate_part (1, 1, TRUE));
/* Back-facing texture */
g_assert (validate_part (2, 1, TRUE));
/* Front-facing texture polygon */
g_assert (validate_part (3, 1, TRUE));
/* Back-facing texture polygon */
g_assert (validate_part (4, 1, TRUE));
/* Regular rectangle */
g_assert (validate_part (5, 1, TRUE));
}
static void
on_paint (ClutterActor *actor, TestState *state)
{
CoglColor clr;
float stage_viewport[4];
CoglMatrix stage_projection;
CoglMatrix stage_modelview;
cogl_color_set_from_4ub (&clr, 0x00, 0x00, 0x00, 0xff);
do_test_backface_culling (state);
/* Since we are going to repeat the test rendering offscreen we clear the
* stage, just to minimize the chance of a some other bug causing us
* mistakenly reading back the results from the stage and giving a false
* posistive. */
cogl_clear (&clr, COGL_BUFFER_BIT_COLOR|COGL_BUFFER_BIT_STENCIL);
/*
* Now repeat the test but rendered to an offscreen framebuffer...
*/
cogl_get_viewport (stage_viewport);
cogl_get_projection_matrix (&stage_projection);
cogl_get_modelview_matrix (&stage_modelview);
cogl_push_framebuffer (state->offscreen);
cogl_clear (&clr, COGL_BUFFER_BIT_COLOR|COGL_BUFFER_BIT_STENCIL);
cogl_set_viewport (stage_viewport[0],
stage_viewport[1],
stage_viewport[2],
stage_viewport[3]);
cogl_set_projection_matrix (&stage_projection);
cogl_set_modelview_matrix (&stage_modelview);
do_test_backface_culling (state);
cogl_pop_framebuffer ();
/* Incase we want feedback of what was drawn offscreen we draw it
* to the stage... */
cogl_set_source_texture (state->offscreen_tex);
cogl_rectangle (0, 0, stage_viewport[2], stage_viewport[3]);
/* 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;
}
static CoglHandle
make_texture (void)
{
guchar *tex_data, *p;
CoglHandle tex;
tex_data = g_malloc (TEXTURE_SIZE * TEXTURE_SIZE * 4);
for (p = tex_data + TEXTURE_SIZE * TEXTURE_SIZE * 4; p > tex_data;)
{
*(--p) = 255;
*(--p) = 0;
*(--p) = 0;
*(--p) = 255;
}
tex = cogl_texture_new_from_data (TEXTURE_SIZE,
TEXTURE_SIZE,
COGL_TEXTURE_NONE,
COGL_PIXEL_FORMAT_RGBA_8888,
COGL_PIXEL_FORMAT_ANY,
TEXTURE_SIZE * 4,
tex_data);
g_free (tex_data);
return tex;
}
void
test_cogl_backface_culling (TestConformSimpleFixture *fixture,
gconstpointer data)
{
TestState state;
CoglHandle tex;
ClutterActor *stage;
float stage_width;
float stage_height;
const ClutterColor stage_color = { 0x0, 0x0, 0x0, 0xff };
ClutterActor *group;
guint idle_source;
stage = clutter_stage_get_default ();
clutter_actor_get_size (stage, &stage_width, &stage_height);
state.offscreen = COGL_INVALID_HANDLE;
state.texture = make_texture ();
tex = cogl_texture_new_with_size (stage_width, stage_height,
COGL_TEXTURE_NO_SLICING,
COGL_PIXEL_FORMAT_ANY); /* internal fmt */
state.offscreen = cogl_offscreen_new_to_texture (tex);
state.offscreen_tex = tex;
clutter_stage_set_color (CLUTTER_STAGE (stage), &stage_color);
group = clutter_group_new ();
clutter_container_add_actor (CLUTTER_CONTAINER (stage), group);
/* 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 (group, "paint", G_CALLBACK (on_paint), &state);
clutter_actor_show_all (stage);
clutter_main ();
g_source_remove (idle_source);
cogl_handle_unref (state.offscreen);
cogl_handle_unref (state.offscreen_tex);
cogl_handle_unref (state.texture);
if (g_test_verbose ())
g_print ("OK\n");
}