mutter/tests/interactive/test-cogl-offscreen.c
Owen W. Taylor c3448314d5 Default to a blend function that expects premultiplied colors
Many operations, like mixing two textures together or alpha-blending
onto a destination with alpha, are done most logically if texture data
is in premultiplied form. We also have many sources of premultiplied
texture data, like X pixmaps, FBOs, cairo surfaces. Rather than trying
to work with two different types of texture data, simplify things by
always premultiplying texture data before uploading to GL.

Because the default blend function is changed to accommodate this,
uses of pure-color CoglMaterial need to be adapted to add
premultiplication.

gl/cogl-texture.c gles/cogl-texture.c: Always premultiply
  non-premultiplied texture data before uploading to GL.

cogl-material.c cogl-material.h: Switch the default blend functions
  to ONE, ONE_MINUS_SRC_ALPHA so they work correctly with premultiplied
  data.

cogl.c: Make cogl_set_source_color() premultiply the color.

cogl.h.in color-material.h: Add some documentation about
  premultiplication and its interaction with color values.

cogl-pango-render.c clutter-texture.c tests/interactive/test-cogl-offscreen.c:
  Use premultiplied colors.

http://bugzilla.openedhand.com/show_bug.cgi?id=1406

Signed-off-by: Robert Bragg <robert@linux.intel.com>
2009-06-11 14:17:52 +01:00

208 lines
5.4 KiB
C

#include <config.h>
#include <glib.h>
#include <gmodule.h>
#include <stdlib.h>
#include <clutter/clutter.h>
#include <cogl/cogl.h>
/* Coglbox declaration
*--------------------------------------------------*/
G_BEGIN_DECLS
#define TEST_TYPE_COGLBOX test_coglbox_get_type()
#define TEST_COGLBOX(obj) \
(G_TYPE_CHECK_INSTANCE_CAST ((obj), \
TEST_TYPE_COGLBOX, TestCoglboxClass))
#define TEST_COGLBOX_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST ((klass), \
TEST_TYPE_COGLBOX, TestCoglboxClass))
#define TEST_IS_COGLBOX(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
TEST_TYPE_COGLBOX))
#define TEST_IS_COGLBOX_CLASS(klass) \
(G_TYPE_CHECK_CLASS_TYPE ((klass), \
TEST_TYPE_COGLBOX))
#define TEST_COGLBOX_GET_CLASS(obj) \
(G_TYPE_INSTANCE_GET_CLASS ((obj), \
TEST_TYPE_COGLBOX, TestCoglboxClass))
typedef struct _TestCoglbox TestCoglbox;
typedef struct _TestCoglboxClass TestCoglboxClass;
typedef struct _TestCoglboxPrivate TestCoglboxPrivate;
struct _TestCoglbox
{
ClutterActor parent;
/*< private >*/
TestCoglboxPrivate *priv;
};
struct _TestCoglboxClass
{
ClutterActorClass parent_class;
/* padding for future expansion */
void (*_test_coglbox1) (void);
void (*_test_coglbox2) (void);
void (*_test_coglbox3) (void);
void (*_test_coglbox4) (void);
};
static GType test_coglbox_get_type (void) G_GNUC_CONST;
G_END_DECLS
/* Coglbox private declaration
*--------------------------------------------------*/
G_DEFINE_TYPE (TestCoglbox, test_coglbox, CLUTTER_TYPE_ACTOR);
#define TEST_COGLBOX_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), TEST_TYPE_COGLBOX, TestCoglboxPrivate))
struct _TestCoglboxPrivate
{
CoglHandle texhand_id;
CoglHandle texture_id;
CoglHandle offscreen_id;
};
/* Coglbox implementation
*--------------------------------------------------*/
static void
test_coglbox_paint(ClutterActor *self)
{
TestCoglboxPrivate *priv = TEST_COGLBOX_GET_PRIVATE (self);
gfloat texcoords[4] = { 0, 0, 1, 1 };
CoglHandle material;
priv = TEST_COGLBOX_GET_PRIVATE (self);
cogl_set_source_color4ub (0x66, 0x66, 0xdd, 0xff);
cogl_rectangle (0, 0, 400, 400);
cogl_set_source_texture (priv->texhand_id);
cogl_rectangle_with_texture_coords (0, 0,
400, 400,
0, 0,
6, 6);
cogl_set_draw_buffer (COGL_OFFSCREEN_BUFFER, priv->offscreen_id);
cogl_set_source_color4ub (0xff, 0, 0, 0xff);
cogl_rectangle (20, 20, 20 + 100, 20 + 100);
cogl_set_source_color4ub (0, 0xff, 0, 0xff);
cogl_rectangle (80, 80, 80 + 100, 80 + 100);
cogl_set_draw_buffer (COGL_WINDOW_BUFFER, 0);
material = cogl_material_new ();
cogl_material_set_color4ub (material, 0x88, 0x88, 0x88, 0x88);
cogl_material_set_layer (material, 0, priv->texture_id);
cogl_set_source (material);
cogl_rectangle_with_texture_coords (100, 100,
300, 300,
texcoords[0],
texcoords[1],
texcoords[2],
texcoords[3]);
}
static void
test_coglbox_finalize (GObject *object)
{
G_OBJECT_CLASS (test_coglbox_parent_class)->finalize (object);
}
static void
test_coglbox_dispose (GObject *object)
{
TestCoglboxPrivate *priv;
priv = TEST_COGLBOX_GET_PRIVATE (object);
cogl_handle_unref (priv->texture_id);
cogl_handle_unref (priv->offscreen_id);
G_OBJECT_CLASS (test_coglbox_parent_class)->dispose (object);
}
static void
test_coglbox_init (TestCoglbox *self)
{
TestCoglboxPrivate *priv;
self->priv = priv = TEST_COGLBOX_GET_PRIVATE(self);
printf ("Loading redhand.png\n");
priv->texhand_id = cogl_texture_new_from_file ("redhand.png",
COGL_TEXTURE_NONE,
COGL_PIXEL_FORMAT_ANY,
NULL);
printf ("Creating texture with size\n");
priv->texture_id = cogl_texture_new_with_size (200, 200,
COGL_TEXTURE_NONE,
COGL_PIXEL_FORMAT_RGB_888);
if (priv->texture_id == COGL_INVALID_HANDLE)
printf ("Failed creating texture with size!\n");
printf ("Creating offscreen\n");
priv->offscreen_id = cogl_offscreen_new_to_texture (priv->texture_id);
if (priv->offscreen_id == COGL_INVALID_HANDLE)
printf ("Failed creating offscreen to texture!\n");
}
static void
test_coglbox_class_init (TestCoglboxClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
ClutterActorClass *actor_class = CLUTTER_ACTOR_CLASS (klass);
gobject_class->finalize = test_coglbox_finalize;
gobject_class->dispose = test_coglbox_dispose;
actor_class->paint = test_coglbox_paint;
g_type_class_add_private (gobject_class, sizeof (TestCoglboxPrivate));
}
static ClutterActor*
test_coglbox_new (void)
{
return g_object_new (TEST_TYPE_COGLBOX, NULL);
}
G_MODULE_EXPORT int
test_cogl_offscreen_main (int argc, char *argv[])
{
ClutterActor *stage;
ClutterActor *coglbox;
clutter_init(&argc, &argv);
/* Stage */
stage = clutter_stage_get_default ();
clutter_actor_set_size (stage, 400, 400);
clutter_stage_set_title (CLUTTER_STAGE (stage), "Cogl Test");
/* Cogl Box */
coglbox = test_coglbox_new ();
clutter_container_add_actor (CLUTTER_CONTAINER (stage), coglbox);
clutter_actor_show_all (stage);
clutter_main ();
return 0;
}