+
+ resource_pool.release_glsl_program(glsl_program_num);
+ glDeleteVertexArrays(1, &vao);
+ check_error();
+}
+
+struct RequiredExtension {
+ int min_equivalent_gl_version;
+ const char extension_name[64];
+};
+const RequiredExtension required_extensions[] = {
+ // We fundamentally need FBOs and floating-point textures.
+ // FBOs are covered by OpenGL 1.5, and are not an extension there.
+ // Floating-point textures are part of OpenGL 3.0 and newer.
+ { 15, "GL_ARB_framebuffer_object" },
+ { 30, "GL_ARB_texture_float" },
+
+ // We assume that we can use non-power-of-two textures without restrictions.
+ { 20, "GL_ARB_texture_non_power_of_two" },
+
+ // We also need GLSL fragment shaders.
+ { 20, "GL_ARB_fragment_shader" },
+ { 20, "GL_ARB_shading_language_100" },
+
+ // FlatInput and YCbCrInput uses PBOs. (They could in theory do without,
+ // but no modern card would really not provide it.)
+ { 21, "GL_ARB_pixel_buffer_object" },
+
+ // ResampleEffect uses RG textures to encode a two-component LUT.
+ // We also need GL_R several places, for single-channel input.
+ { 30, "GL_ARB_texture_rg" },
+};
+
+bool check_extensions()
+{
+ // GLES generally doesn't use extensions as actively as desktop OpenGL.
+ // For now, we say that for GLES, we require GLES 3, which has everything
+ // we need.
+ if (!epoxy_is_desktop_gl()) {
+ if (epoxy_gl_version() >= 30) {
+ movit_srgb_textures_supported = true;
+ movit_shader_rounding_supported = true;
+ return true;
+ } else {
+ fprintf(stderr, "Movit system requirements: GLES version %.1f is too old (GLES 3.0 needed).\n",
+ 0.1f * epoxy_gl_version());
+ fprintf(stderr, "Movit initialization failed.\n");
+ return false;
+ }
+ }
+
+ // Check all extensions, and output errors for the ones that we are missing.
+ bool all_ok = true;
+ int gl_version = epoxy_gl_version();
+
+ for (unsigned i = 0; i < sizeof(required_extensions) / sizeof(required_extensions[0]); ++i) {
+ if (gl_version < required_extensions[i].min_equivalent_gl_version &&
+ !epoxy_has_gl_extension(required_extensions[i].extension_name)) {
+ fprintf(stderr, "Movit system requirements: Needs extension '%s' or at least OpenGL version %.1f (has version %.1f)\n",
+ required_extensions[i].extension_name,
+ 0.1f * required_extensions[i].min_equivalent_gl_version,
+ 0.1f * gl_version);
+ all_ok = false;
+ }
+ }
+
+ if (!all_ok) {
+ fprintf(stderr, "Movit initialization failed.\n");
+ return false;
+ }
+
+ // sRGB texture decode would be nice, but are not mandatory
+ // (GammaExpansionEffect can do the same thing if needed).
+ movit_srgb_textures_supported =
+ (epoxy_gl_version() >= 21 || epoxy_has_gl_extension("GL_EXT_texture_sRGB"));
+
+ // We may want to use round() at the end of the final shader,
+ // if supported. We need either GLSL 1.30 or this extension to do that,
+ // and 1.30 brings with it other things that we don't want to demand
+ // for now.
+ movit_shader_rounding_supported =
+ (epoxy_gl_version() >= 30 || epoxy_has_gl_extension("GL_EXT_gpu_shader4"));
+
+ // The user can specify that they want a timing report for each
+ // phase in an effect chain. However, that depends on this extension;
+ // without it, we do cannot even create the query objects.
+ movit_timer_queries_supported =
+ (epoxy_gl_version() >= 33 || epoxy_has_gl_extension("GL_ARB_timer_query"));
+
+ return true;
+}
+
+double get_glsl_version()
+{
+ char *glsl_version_str = strdup((const char *)glGetString(GL_SHADING_LANGUAGE_VERSION));
+
+ // Skip past the first period.
+ char *ptr = strchr(glsl_version_str, '.');
+ assert(ptr != NULL);
+ ++ptr;
+
+ // Now cut the string off at the next period or space, whatever comes first
+ // (unless the string ends first).
+ while (*ptr && *ptr != '.' && *ptr != ' ') {
+ ++ptr;
+ }
+ *ptr = '\0';
+
+ // Now we have something on the form X.YY. We convert it to a float, and hope
+ // that if it's inexact (e.g. 1.30), atof() will round the same way the
+ // compiler will.
+ float glsl_version = atof(glsl_version_str);
+ free(glsl_version_str);
+
+ return glsl_version;
+}
+
+void APIENTRY debug_callback(GLenum source,
+ GLenum type,
+ GLuint id,
+ GLenum severity,
+ GLsizei length,
+ const char *message,
+ const void *userParam)
+{
+ printf("Debug: %s\n", message);