cairo_status_t
_cairo_gl_context_init_shaders (cairo_gl_context_t *ctx)
{
static const char *fill_fs_source =
"#ifdef GL_ES\n"
"precision mediump float;\n"
"#endif\n"
"uniform vec4 color;\n"
"void main()\n"
"{\n"
" gl_FragColor = color;\n"
"}\n";
cairo_status_t status;
if (_cairo_gl_get_version () >= CAIRO_GL_VERSION_ENCODE (2, 0) ||
(_cairo_gl_has_extension ("GL_ARB_shader_objects") &&
_cairo_gl_has_extension ("GL_ARB_fragment_shader") &&
_cairo_gl_has_extension ("GL_ARB_vertex_shader"))) {
ctx->has_shader_support = TRUE;
} else {
ctx->has_shader_support = FALSE;
fprintf (stderr, "Error: The cairo gl backend requires shader support!\n");
return CAIRO_STATUS_DEVICE_ERROR;
}
memset (ctx->vertex_shaders, 0, sizeof (ctx->vertex_shaders));
status = _cairo_cache_init (&ctx->shaders,
ctx->gl_flavor == CAIRO_GL_FLAVOR_DESKTOP ?
_cairo_gl_shader_cache_equal_desktop :
_cairo_gl_shader_cache_equal_gles2,
NULL,
_cairo_gl_shader_cache_destroy,
CAIRO_GL_MAX_SHADERS_PER_CONTEXT);
if (unlikely (status))
return status;
_cairo_gl_shader_init (&ctx->fill_rectangles_shader);
status = _cairo_gl_shader_compile_and_link (ctx,
&ctx->fill_rectangles_shader,
NULL,
NULL,
FALSE,
fill_fs_source);
if (unlikely (status))
return status;
return CAIRO_STATUS_SUCCESS;
}
cairo_status_t
_cairo_gl_get_shader_by_type (cairo_gl_context_t *ctx,
cairo_gl_operand_t *source,
cairo_gl_operand_t *mask,
cairo_bool_t use_coverage,
cairo_gl_shader_in_t in,
cairo_gl_shader_t **shader)
{
cairo_shader_cache_entry_t lookup, *entry;
char *fs_source;
cairo_status_t status;
lookup.ctx = ctx;
lookup.vertex = cairo_gl_var_type_hash (cairo_gl_operand_get_var_type (source),
cairo_gl_operand_get_var_type (mask),
use_coverage,
CAIRO_GL_VAR_NONE);
lookup.src = source->type;
lookup.mask = mask->type;
lookup.dest = CAIRO_GL_OPERAND_NONE;
lookup.use_coverage = use_coverage;
lookup.in = in;
lookup.src_gl_filter = _cairo_gl_operand_get_gl_filter (source);
lookup.src_border_fade = _cairo_gl_shader_needs_border_fade (source);
lookup.src_extend = _cairo_gl_operand_get_extend (source);
lookup.mask_gl_filter = _cairo_gl_operand_get_gl_filter (mask);
lookup.mask_border_fade = _cairo_gl_shader_needs_border_fade (mask);
lookup.mask_extend = _cairo_gl_operand_get_extend (mask);
lookup.base.hash = _cairo_gl_shader_cache_hash (&lookup);
lookup.base.size = 1;
entry = _cairo_cache_lookup (&ctx->shaders, &lookup.base);
if (entry) {
assert (entry->shader.program);
*shader = &entry->shader;
return CAIRO_STATUS_SUCCESS;
}
status = cairo_gl_shader_get_fragment_source (ctx,
in,
source,
mask,
use_coverage,
CAIRO_GL_OPERAND_NONE,
&fs_source);
if (unlikely (status))
return status;
entry = malloc (sizeof (cairo_shader_cache_entry_t));
if (unlikely (entry == NULL)) {
free (fs_source);
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
}
memcpy (entry, &lookup, sizeof (cairo_shader_cache_entry_t));
entry->ctx = ctx;
_cairo_gl_shader_init (&entry->shader);
status = _cairo_gl_shader_compile_and_link (ctx,
&entry->shader,
cairo_gl_operand_get_var_type (source),
cairo_gl_operand_get_var_type (mask),
use_coverage,
fs_source);
free (fs_source);
if (unlikely (status)) {
free (entry);
return status;
}
_cairo_gl_shader_set_samplers (ctx, &entry->shader);
status = _cairo_cache_insert (&ctx->shaders, &entry->base);
if (unlikely (status)) {
_cairo_gl_shader_fini (ctx, &entry->shader);
free (entry);
return status;
}
*shader = &entry->shader;
return CAIRO_STATUS_SUCCESS;
}
