void init_quad(RenderingContext* ctx) {
float vertices[12] = {
0.0, 0.0, 0.0,
0.0, 1.0, 0.0,
1.0, 0.0, 0.0,
1.0, 1.0, 0.0
};
float tex_coords[8] = {
0.0, 1.0,
0.0, 0.0,
1.0, 1.0,
1.0, 0.0
};
_vao = ctx->create_vertex_array();
ScopedBind<VertexArray> bind_vao(ctx, _vao);
// vertices
{
_vertex_vbo = ctx->create_vertex_buffer();
ScopedBind<VertexBuffer> bind_vbo(ctx, _vertex_vbo);
ctx->upload(_vertex_vbo, range(vertices, 12).bytes());
ctx->define_vertex_attribute(0, gpu::FLOAT, 3, 0, 0);
ctx->enable_vertex_attribute(0);
}
// texture coordinates
{
_texcoord_vbo = ctx->create_vertex_buffer();
ScopedBind<VertexBuffer> bind_vbo(ctx, _texcoord_vbo);
ctx->upload(_texcoord_vbo, range(tex_coords, 8).bytes());
ctx->define_vertex_attribute(1, gpu::FLOAT, 2, 0, 0);
ctx->enable_vertex_attribute(1);
}
}
void draw_unit_quad(RenderingContext* ctx, DrawMode mode) {
ctx->enable_vertex_attribute(0);
ctx->enable_vertex_attribute(1);
gpu::ScopedBind<VertexArray> bind_vao(ctx, _vao);
ctx->draw_arrays(mode, 0, 4);
}
void
gdk_gl_texture_quads (GdkGLContext *paint_context,
guint texture_target,
int n_quads,
GdkTexturedQuad *quads)
{
GdkGLContextPaintData *paint_data = gdk_gl_context_get_paint_data (paint_context);
GdkGLContextProgram *program;
GdkWindow *window = gdk_gl_context_get_window (paint_context);
int window_scale = gdk_window_get_scale_factor (window);
float w = gdk_window_get_width (window) * window_scale;
float h = gdk_window_get_height (window) * window_scale;
int i;
float *vertex_buffer_data;
bind_vao (paint_data);
if (paint_data->tmp_vertex_buffer == 0)
glGenBuffers(1, &paint_data->tmp_vertex_buffer);
if (texture_target == GL_TEXTURE_RECTANGLE_ARB)
use_texture_rect_program (paint_data);
else
use_texture_2d_program (paint_data);
program = paint_data->current_program;
glActiveTexture (GL_TEXTURE0);
glUniform1i(program->map_location, 0); /* Use texture unit 0 */
glEnableVertexAttribArray (program->position_location);
glEnableVertexAttribArray (program->uv_location);
glBindBuffer (GL_ARRAY_BUFFER, paint_data->tmp_vertex_buffer);
glVertexAttribPointer (program->position_location, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 4, NULL);
glVertexAttribPointer (program->uv_location, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 4, (void *) (sizeof(float) * 2));
#define VERTEX_SIZE 4
#define QUAD_N_VERTICES 6
#define QUAD_SIZE (VERTEX_SIZE * QUAD_N_VERTICES)
vertex_buffer_data = g_new (float, n_quads * QUAD_SIZE);
for (i = 0; i < n_quads; i++)
{
GdkTexturedQuad *quad = &quads[i];
float vertex_data[] = {
(quad->x1 * 2) / w - 1, (quad->y1 * 2) / h - 1, quad->u1, quad->v1,
(quad->x1 * 2) / w - 1, (quad->y2 * 2) / h - 1, quad->u1, quad->v2,
(quad->x2 * 2) / w - 1, (quad->y1 * 2) / h - 1, quad->u2, quad->v1,
(quad->x2 * 2) / w - 1, (quad->y2 * 2) / h - 1, quad->u2, quad->v2,
(quad->x1 * 2) / w - 1, (quad->y2 * 2) / h - 1, quad->u1, quad->v2,
(quad->x2 * 2) / w - 1, (quad->y1 * 2) / h - 1, quad->u2, quad->v1,
};
float *vertex = &vertex_buffer_data[i * QUAD_SIZE];
memcpy (vertex, vertex_data, sizeof(vertex_data));
}
glBufferData (GL_ARRAY_BUFFER, sizeof(float) * n_quads * QUAD_SIZE, vertex_buffer_data, GL_STREAM_DRAW);
glDrawArrays (GL_TRIANGLES, 0, n_quads * QUAD_N_VERTICES);
g_free (vertex_buffer_data);
glDisableVertexAttribArray (program->position_location);
glDisableVertexAttribArray (program->uv_location);
}
