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#include <cogl/cogl.h>
#include <glib.h>
#include <stdio.h>
typedef struct _Data
{
CoglContext *ctx;
CoglFramebuffer *fb;
CoglPrimitive *triangle;
CoglPipeline *pipeline;
unsigned int redraw_idle;
CoglBool is_dirty;
CoglBool draw_ready;
} Data;
static gboolean
paint_cb (void *user_data)
{
Data *data = user_data;
data->redraw_idle = 0;
data->is_dirty = FALSE;
data->draw_ready = FALSE;
cogl_framebuffer_clear4f (data->fb, COGL_BUFFER_BIT_COLOR, 0, 0, 0, 1);
cogl_primitive_draw (data->triangle,
data->fb,
data->pipeline);
cogl_onscreen_swap_buffers (data->fb);
return G_SOURCE_REMOVE;
}
static void
maybe_redraw (Data *data)
{
if (data->is_dirty && data->draw_ready && data->redraw_idle == 0) {
/* We'll draw on idle instead of drawing immediately so that
* if Cogl reports multiple dirty rectangles we won't
* redundantly draw multiple frames */
data->redraw_idle = g_idle_add (paint_cb, data);
}
}
static void
frame_event_cb (CoglOnscreen *onscreen,
CoglFrameEvent event,
CoglFrameInfo *info,
void *user_data)
{
Data *data = user_data;
if (event == COGL_FRAME_EVENT_SYNC) {
data->draw_ready = TRUE;
maybe_redraw (data);
}
}
static void
dirty_cb (CoglOnscreen *onscreen,
const CoglOnscreenDirtyInfo *info,
void *user_data)
{
Data *data = user_data;
data->is_dirty = TRUE;
maybe_redraw (data);
}
int
main (int argc, char **argv)
{
Data data;
CoglOnscreen *onscreen;
CoglError *error = NULL;
CoglVertexP2C4 triangle_vertices[] = {
{0, 0.7, 0xff, 0x00, 0x00, 0xff},
{-0.7, -0.7, 0x00, 0xff, 0x00, 0xff},
{0.7, -0.7, 0x00, 0x00, 0xff, 0xff}
};
GSource *cogl_source;
GMainLoop *loop;
data.redraw_idle = 0;
data.is_dirty = FALSE;
data.draw_ready = TRUE;
data.ctx = cogl_context_new (NULL, &error);
if (!data.ctx) {
fprintf (stderr, "Failed to create context: %s\n", error->message);
return 1;
}
onscreen = cogl_onscreen_new (data.ctx, 640, 480);
cogl_onscreen_show (onscreen);
data.fb = onscreen;
cogl_onscreen_set_resizable (onscreen, TRUE);
data.triangle = cogl_primitive_new_p2c4 (data.ctx,
COGL_VERTICES_MODE_TRIANGLES,
3, triangle_vertices);
data.pipeline = cogl_pipeline_new (data.ctx);
cogl_source = cogl_glib_source_new (data.ctx, G_PRIORITY_DEFAULT);
g_source_attach (cogl_source, NULL);
cogl_onscreen_add_frame_callback (data.fb,
frame_event_cb,
&data,
NULL); /* destroy notify */
cogl_onscreen_add_dirty_callback (data.fb,
dirty_cb,
&data,
NULL); /* destroy notify */
loop = g_main_loop_new (NULL, TRUE);
g_main_loop_run (loop);
return 0;
}
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