const cairo_compositor_t *
_cairo_gl_msaa_compositor_get (void)
{
    static cairo_compositor_t compositor;
    if (compositor.delegate == NULL)
	_cairo_gl_msaa_compositor_init (&compositor,
					_cairo_gl_span_compositor_get ());

    return &compositor;
}
Exemple #2
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cairo_status_t
_cairo_gl_context_init (cairo_gl_context_t *ctx)
{
    cairo_status_t status;
    cairo_gl_dispatch_t *dispatch = &ctx->dispatch;
    int gl_version = _cairo_gl_get_version ();
    cairo_gl_flavor_t gl_flavor = _cairo_gl_get_flavor ();
    int n;

    _cairo_device_init (&ctx->base, &_cairo_gl_device_backend);

    /* XXX The choice of compositor should be made automatically at runtime.
     * However, it is useful to force one particular compositor whilst
     * testing.
     */
     if (_cairo_gl_msaa_compositor_enabled ())
	ctx->compositor = _cairo_gl_msaa_compositor_get ();
    else
	ctx->compositor = _cairo_gl_span_compositor_get ();


    ctx->thread_aware = TRUE;

    memset (ctx->glyph_cache, 0, sizeof (ctx->glyph_cache));
    cairo_list_init (&ctx->fonts);

    /* Support only GL version >= 1.3 */
    if (gl_version < CAIRO_GL_VERSION_ENCODE (1, 3))
	return _cairo_error (CAIRO_STATUS_DEVICE_ERROR);

    /* Check for required extensions */
    if (gl_flavor == CAIRO_GL_FLAVOR_DESKTOP) {
	if (_cairo_gl_has_extension ("GL_ARB_texture_non_power_of_two")) {
	    ctx->tex_target = GL_TEXTURE_2D;
	    ctx->has_npot_repeat = TRUE;
	} else if (_cairo_gl_has_extension ("GL_ARB_texture_rectangle")) {
	    ctx->tex_target = GL_TEXTURE_RECTANGLE;
	    ctx->has_npot_repeat = FALSE;
	} else
	    return _cairo_error (CAIRO_STATUS_DEVICE_ERROR);
    } else {
	ctx->tex_target = GL_TEXTURE_2D;
	if (_cairo_gl_has_extension ("GL_OES_texture_npot"))
	    ctx->has_npot_repeat = TRUE;
	else
	    ctx->has_npot_repeat = FALSE;
    }

    if (gl_flavor == CAIRO_GL_FLAVOR_DESKTOP &&
	gl_version < CAIRO_GL_VERSION_ENCODE (2, 1) &&
	! _cairo_gl_has_extension ("GL_ARB_pixel_buffer_object"))
	return _cairo_error (CAIRO_STATUS_DEVICE_ERROR);

    if (gl_flavor == CAIRO_GL_FLAVOR_ES &&
	! _cairo_gl_has_extension ("GL_EXT_texture_format_BGRA8888"))
	return _cairo_error (CAIRO_STATUS_DEVICE_ERROR);

    ctx->has_map_buffer = (gl_flavor == CAIRO_GL_FLAVOR_DESKTOP ||
			   (gl_flavor == CAIRO_GL_FLAVOR_ES &&
			    _cairo_gl_has_extension ("GL_OES_mapbuffer")));

    ctx->has_mesa_pack_invert =
	_cairo_gl_has_extension ("GL_MESA_pack_invert");

    ctx->has_packed_depth_stencil =
	((gl_flavor == CAIRO_GL_FLAVOR_DESKTOP &&
	 _cairo_gl_has_extension ("GL_EXT_packed_depth_stencil")) ||
	(gl_flavor == CAIRO_GL_FLAVOR_ES &&
	 _cairo_gl_has_extension ("GL_OES_packed_depth_stencil")));

    ctx->num_samples = 1;

#if CAIRO_HAS_GL_SURFACE
    if (ctx->has_packed_depth_stencil &&
	_cairo_gl_has_extension ("GL_ARB_framebuffer_object")) {
	glGetIntegerv(GL_MAX_SAMPLES_EXT, &ctx->num_samples);
    }
#endif

#if CAIRO_HAS_GLESV2_SURFACE && defined(GL_MAX_SAMPLES_EXT)
    if (ctx->has_packed_depth_stencil &&
	_cairo_gl_has_extension ("GL_EXT_multisampled_render_to_texture")) {
	glGetIntegerv(GL_MAX_SAMPLES_EXT, &ctx->num_samples);
    }
#endif
    ctx->supports_msaa = ctx->num_samples > 1;
    if (ctx->num_samples > MAX_MSAA_SAMPLES)
	ctx->num_samples = MAX_MSAA_SAMPLES;


    ctx->current_operator = -1;
    ctx->gl_flavor = gl_flavor;

    status = _cairo_gl_context_init_shaders (ctx);
    if (unlikely (status))
        return status;

    status = _cairo_cache_init (&ctx->gradients,
                                _cairo_gl_gradient_equal,
                                NULL,
                                (cairo_destroy_func_t) _cairo_gl_gradient_destroy,
                                CAIRO_GL_GRADIENT_CACHE_SIZE);
    if (unlikely (status))
        return status;

    ctx->vb = malloc (CAIRO_GL_VBO_SIZE);
    if (unlikely (ctx->vb == NULL)) {
	    _cairo_cache_fini (&ctx->gradients);
	    return _cairo_error (CAIRO_STATUS_NO_MEMORY);
    }

    ctx->primitive_type = CAIRO_GL_PRIMITIVE_TYPE_TRIANGLES;
    _cairo_array_init (&ctx->tristrip_indices, sizeof (unsigned short));

    /* PBO for any sort of texture upload */
    dispatch->GenBuffers (1, &ctx->texture_load_pbo);

    ctx->max_framebuffer_size = 0;
    glGetIntegerv (GL_MAX_RENDERBUFFER_SIZE, &ctx->max_framebuffer_size);
    ctx->max_texture_size = 0;
    glGetIntegerv (GL_MAX_TEXTURE_SIZE, &ctx->max_texture_size);
    ctx->max_textures = 0;
    glGetIntegerv (GL_MAX_TEXTURE_IMAGE_UNITS, &ctx->max_textures);

    for (n = 0; n < ARRAY_LENGTH (ctx->glyph_cache); n++)
	_cairo_gl_glyph_cache_init (&ctx->glyph_cache[n]);

    return CAIRO_STATUS_SUCCESS;
}