summaryrefslogtreecommitdiff
path: root/examples/cogl-gles2-context.c
blob: de66c21189d23aba9f3c14d49ef49b5bdeb9a855 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
#include <cogl/cogl.h>
#include <cogl/cogl-gles2.h>
#include <glib.h>
#include <stdio.h>

#define OFFSCREEN_WIDTH 100
#define OFFSCREEN_HEIGHT 100

typedef struct _Data
{
    CoglContext *ctx;
    CoglFramebuffer *fb;
    CoglPrimitive *triangle;
    CoglPipeline *pipeline;

    CoglTexture *offscreen_texture;
    CoglOffscreen *offscreen;
    CoglGLES2Context *gles2_ctx;
    const CoglGLES2Vtable *gles2_vtable;
} Data;

static gboolean
paint_cb (void *user_data)
{
    Data *data = user_data;
    CoglError *error = NULL;
    const CoglGLES2Vtable *gles2 = data->gles2_vtable;

    /* Draw scene with GLES2 */
    if (!cogl_push_gles2_context (data->ctx,
                                  data->gles2_ctx,
                                  data->fb,
                                  data->fb,
                                  &error))
    {
        g_error ("Failed to push gles2 context: %s\n", error->message);
    }

    /* Clear offscreen framebuffer with a random color */
    gles2->glClearColor (g_random_double (),
                         g_random_double (),
                         g_random_double (),
                         1.0f);
    gles2->glClear (GL_COLOR_BUFFER_BIT);

    cogl_pop_gles2_context (data->ctx);

    /* Draw scene with Cogl */
    cogl_framebuffer_draw_primitive (data->fb, data->pipeline, data->triangle);

    cogl_onscreen_swap_buffers (COGL_ONSCREEN (data->fb));

    return FALSE; /* remove the callback */
}

static void
frame_event_cb (CoglOnscreen *onscreen,
                CoglFrameEvent event,
                CoglFrameInfo *info,
                void *user_data)
{
    if (event == COGL_FRAME_EVENT_SYNC)
        paint_cb (user_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;
    CoglRenderer *renderer;
    CoglDisplay *display;

    renderer = cogl_renderer_new ();
    cogl_renderer_add_constraint (renderer,
                                  COGL_RENDERER_CONSTRAINT_SUPPORTS_COGL_GLES2);
    display = cogl_display_new (renderer, NULL);
    data.ctx = cogl_context_new (display, NULL);

    onscreen = cogl_onscreen_new (data.ctx, 640, 480);
    cogl_onscreen_show (onscreen);
    data.fb = COGL_FRAMEBUFFER (onscreen);

    /* Prepare onscreen primitive */
    data.triangle = cogl_primitive_new_p2c4 (data.ctx,
                                             COGL_VERTICES_MODE_TRIANGLES,
                                             3, triangle_vertices);
    data.pipeline = cogl_pipeline_new (data.ctx);

    data.offscreen_texture =
      cogl_texture_new_with_size (OFFSCREEN_WIDTH,
                                  OFFSCREEN_HEIGHT,
                                  COGL_TEXTURE_NO_SLICING,
                                  COGL_PIXEL_FORMAT_ANY);
    data.offscreen = cogl_offscreen_new_to_texture (data.offscreen_texture);

    data.gles2_ctx = cogl_gles2_context_new (data.ctx, &error);
    if (!data.gles2_ctx) {
        g_error ("Failed to create GLES2 context: %s\n", error->message);
    }

    data.gles2_vtable = cogl_gles2_context_get_vtable (data.gles2_ctx);

    /* Draw scene with GLES2 */
    if (!cogl_push_gles2_context (data.ctx,
                                  data.gles2_ctx,
                                  data.fb,
                                  data.fb,
                                  &error))
    {
        g_error ("Failed to push gles2 context: %s\n", error->message);
    }

    cogl_pop_gles2_context (data.ctx);

    cogl_source = cogl_glib_source_new (data.ctx, G_PRIORITY_DEFAULT);

    g_source_attach (cogl_source, NULL);

    cogl_onscreen_add_frame_callback (COGL_ONSCREEN (data.fb),
                                      frame_event_cb,
                                      &data,
                                      NULL); /* destroy notify */

    g_idle_add (paint_cb, &data);

    loop = g_main_loop_new (NULL, TRUE);
    g_main_loop_run (loop);

    return 0;
}