+template<class T>
+void EffectChainTester::internal_run(T *out_data, GLenum internal_format, GLenum format, Colorspace color_space, GammaCurve gamma_curve, OutputAlphaFormat alpha_format)
+{
+ if (!finalized) {
+ finalize_chain(color_space, gamma_curve, alpha_format);
+ }
+
+ GLuint type;
+ if (framebuffer_format == GL_RGBA8) {
+ type = GL_UNSIGNED_BYTE;
+ } else if (framebuffer_format == GL_RGBA16F || framebuffer_format == GL_RGBA32F) {
+ type = GL_FLOAT;
+ } else {
+ // Add more here as needed.
+ assert(false);
+ }
+
+ GLuint fbo, texnum;
+
+ glGenTextures(1, &texnum);
+ check_error();
+ glBindTexture(GL_TEXTURE_2D, texnum);
+ check_error();
+ glTexImage2D(GL_TEXTURE_2D, 0, framebuffer_format, width, height, 0, GL_RGBA, type, NULL);
+ check_error();
+
+ glGenFramebuffers(1, &fbo);
+ check_error();
+ glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+ check_error();
+ glFramebufferTexture2D(
+ GL_FRAMEBUFFER,
+ GL_COLOR_ATTACHMENT0,
+ GL_TEXTURE_2D,
+ texnum,
+ 0);
+ check_error();
+ glBindFramebuffer(GL_FRAMEBUFFER, 0);
+ check_error();
+
+ chain.render_to_fbo(fbo, width, height);
+
+ glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+ check_error();
+ if (!epoxy_is_desktop_gl() && (format == GL_RED || format == GL_BLUE || format == GL_ALPHA)) {
+ // GLES will only read GL_RGBA.
+ T *temp = new T[width * height * 4];
+ glReadPixels(0, 0, width, height, GL_RGBA, internal_format, temp);
+ check_error();
+ if (format == GL_ALPHA) {
+ for (unsigned i = 0; i < width * height; ++i) {
+ out_data[i] = temp[i * 4 + 3];
+ }
+ } else if (format == GL_BLUE) {
+ for (unsigned i = 0; i < width * height; ++i) {
+ out_data[i] = temp[i * 4 + 2];
+ }
+ } else {
+ for (unsigned i = 0; i < width * height; ++i) {
+ out_data[i] = temp[i * 4];
+ }