1 #define GL_GLEXT_PROTOTYPES 1
11 #include "effect_chain.h"
12 #include "gamma_expansion_effect.h"
13 #include "gamma_compression_effect.h"
14 #include "lift_gamma_gain_effect.h"
15 #include "colorspace_conversion_effect.h"
16 #include "saturation_effect.h"
17 #include "mirror_effect.h"
18 #include "vignette_effect.h"
19 #include "blur_effect.h"
21 EffectChain::EffectChain(unsigned width, unsigned height)
22 : width(width), height(height), use_srgb_texture_format(false), finalized(false) {}
24 void EffectChain::add_input(const ImageFormat &format)
26 input_format = format;
27 current_color_space = format.color_space;
28 current_gamma_curve = format.gamma_curve;
31 void EffectChain::add_output(const ImageFormat &format)
33 output_format = format;
36 Effect *instantiate_effect(EffectId effect)
39 case EFFECT_GAMMA_EXPANSION:
40 return new GammaExpansionEffect();
41 case EFFECT_GAMMA_COMPRESSION:
42 return new GammaCompressionEffect();
43 case EFFECT_COLOR_SPACE_CONVERSION:
44 return new ColorSpaceConversionEffect();
45 case EFFECT_LIFT_GAMMA_GAIN:
46 return new LiftGammaGainEffect();
47 case EFFECT_SATURATION:
48 return new SaturationEffect();
50 return new MirrorEffect();
52 return new VignetteEffect();
54 return new BlurEffect();
59 void EffectChain::normalize_to_linear_gamma()
61 if (current_gamma_curve == GAMMA_sRGB) {
62 // TODO: check if the extension exists
63 use_srgb_texture_format = true;
65 GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
66 gamma_conversion->set_int("source_curve", current_gamma_curve);
67 effects.push_back(gamma_conversion);
69 current_gamma_curve = GAMMA_LINEAR;
72 void EffectChain::normalize_to_srgb()
74 assert(current_gamma_curve == GAMMA_LINEAR);
75 ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
76 colorspace_conversion->set_int("source_space", current_color_space);
77 colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
78 effects.push_back(colorspace_conversion);
79 current_color_space = COLORSPACE_sRGB;
82 Effect *EffectChain::add_effect(EffectId effect_id)
84 Effect *effect = instantiate_effect(effect_id);
86 if (effect->needs_linear_light() && current_gamma_curve != GAMMA_LINEAR) {
87 normalize_to_linear_gamma();
90 if (effect->needs_srgb_primaries() && current_color_space != COLORSPACE_sRGB) {
94 effects.push_back(effect);
98 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
99 std::string replace_prefix(const std::string &text, const std::string &prefix)
104 while (start < text.size()) {
105 size_t pos = text.find("PREFIX(", start);
106 if (pos == std::string::npos) {
107 output.append(text.substr(start, std::string::npos));
111 output.append(text.substr(start, pos - start));
112 output.append(prefix);
115 pos += strlen("PREFIX(");
117 // Output stuff until we find the matching ), which we then eat.
119 size_t end_arg_pos = pos;
120 while (end_arg_pos < text.size()) {
121 if (text[end_arg_pos] == '(') {
123 } else if (text[end_arg_pos] == ')') {
131 output.append(text.substr(pos, end_arg_pos - pos));
139 EffectChain::Phase EffectChain::compile_glsl_program(unsigned start_index, unsigned end_index)
141 bool input_needs_mipmaps = false;
142 std::string frag_shader = read_file("header.frag");
143 for (unsigned i = start_index; i < end_index; ++i) {
145 sprintf(effect_id, "eff%d", i);
148 frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
149 frag_shader += replace_prefix(effects[i]->output_convenience_uniforms(), effect_id);
150 frag_shader += replace_prefix(effects[i]->output_fragment_shader(), effect_id);
151 frag_shader += "#undef PREFIX\n";
152 frag_shader += "#undef FUNCNAME\n";
153 frag_shader += "#undef LAST_INPUT\n";
154 frag_shader += std::string("#define LAST_INPUT ") + effect_id + "\n";
157 input_needs_mipmaps |= effects[i]->needs_mipmaps();
159 frag_shader.append(read_file("footer.frag"));
160 printf("%s\n", frag_shader.c_str());
162 GLuint glsl_program_num = glCreateProgram();
163 GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
164 GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
165 glAttachShader(glsl_program_num, vs_obj);
167 glAttachShader(glsl_program_num, fs_obj);
169 glLinkProgram(glsl_program_num);
173 phase.glsl_program_num = glsl_program_num;
174 phase.input_needs_mipmaps = input_needs_mipmaps;
175 phase.start = start_index;
176 phase.end = end_index;
181 void EffectChain::finalize()
183 // Add normalizers to get the output format right.
184 if (current_color_space != output_format.color_space) {
185 ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
186 colorspace_conversion->set_int("source_space", current_color_space);
187 colorspace_conversion->set_int("destination_space", output_format.color_space);
188 effects.push_back(colorspace_conversion);
189 current_color_space = output_format.color_space;
191 if (current_gamma_curve != output_format.gamma_curve) {
192 if (current_gamma_curve != GAMMA_LINEAR) {
193 normalize_to_linear_gamma();
195 assert(current_gamma_curve == GAMMA_LINEAR);
196 GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
197 gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
198 effects.push_back(gamma_conversion);
199 current_gamma_curve = output_format.gamma_curve;
202 // Construct the GLSL programs. We end a program every time we come
203 // to an effect marked as "needs many samples" (ie. "please let me
204 // sample directly from a texture, with no arithmetic in-between"),
205 // and of course at the end.
207 for (unsigned i = 0; i < effects.size(); ++i) {
208 if (effects[i]->needs_many_samples() && i != start) {
209 phases.push_back(compile_glsl_program(start, i));
213 phases.push_back(compile_glsl_program(start, effects.size()));
215 // If we have more than one phase, we need intermediate render-to-texture.
216 // Construct an FBO, and then as many textures as we need.
217 if (phases.size() > 1) {
218 glGenFramebuffers(1, &fbo);
220 unsigned num_textures = std::max<int>(phases.size() - 1, 2);
221 glGenTextures(num_textures, temp_textures);
223 unsigned char *empty = new unsigned char[width * height * 4];
224 for (unsigned i = 0; i < num_textures; ++i) {
225 glBindTexture(GL_TEXTURE_2D, temp_textures[i]);
227 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, empty);
233 // Translate the input format to OpenGL's enums.
234 GLenum internal_format;
235 if (use_srgb_texture_format) {
236 internal_format = GL_SRGB8;
238 internal_format = GL_RGBA8;
240 if (input_format.pixel_format == FORMAT_RGB) {
243 } else if (input_format.pixel_format == FORMAT_RGBA) {
246 } else if (input_format.pixel_format == FORMAT_BGR) {
249 } else if (input_format.pixel_format == FORMAT_BGRA) {
256 // Create PBO to hold the texture holding the input image, and then the texture itself.
257 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
259 glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, width * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
262 void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
263 memset(mapped_pbo, 0, width * height * bytes_per_pixel);
264 glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
266 glGenTextures(1, &source_image_num);
268 glBindTexture(GL_TEXTURE_2D, source_image_num);
270 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
272 glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
274 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
280 void EffectChain::render_to_screen(unsigned char *src)
284 // Copy the pixel data into the PBO.
285 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
287 void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
288 memcpy(mapped_pbo, src, width * height * bytes_per_pixel);
289 glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
292 // Re-upload the texture from the PBO.
293 glActiveTexture(GL_TEXTURE0);
295 glBindTexture(GL_TEXTURE_2D, source_image_num);
297 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
299 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
301 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
303 glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
309 glDisable(GL_DEPTH_TEST);
311 glDepthMask(GL_FALSE);
314 glMatrixMode(GL_PROJECTION);
316 glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
318 glMatrixMode(GL_MODELVIEW);
321 if (phases.size() > 1) {
322 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
326 for (unsigned phase = 0; phase < phases.size(); ++phase) {
327 // Set up inputs and outputs for this phase.
329 // First phase reads from the input texture (which is already bound).
331 glBindTexture(GL_TEXTURE_2D, temp_textures[(phase + 1) % 2]);
334 if (phases[phase].input_needs_mipmaps) {
335 glGenerateMipmap(GL_TEXTURE_2D);
337 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
340 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
344 if (phase == phases.size() - 1) {
345 // Last phase goes directly to the screen.
346 glBindFramebuffer(GL_FRAMEBUFFER, 0);
349 glFramebufferTexture2D(
351 GL_COLOR_ATTACHMENT0,
353 temp_textures[phase % 2],
357 // We have baked an upside-down transform into the quad coordinates,
358 // since the typical graphics program will have the origin at the upper-left,
359 // while OpenGL uses lower-left. In the next ones, however, the origin
360 // is all right, and we need to reverse that.
362 glTranslatef(0.0f, 1.0f, 0.0f);
363 glScalef(1.0f, -1.0f, 1.0f);
366 // Give the required parameters to all the effects.
367 glUseProgram(phases[phase].glsl_program_num);
370 glUniform1i(glGetUniformLocation(phases[phase].glsl_program_num, "input_tex"), 0);
373 unsigned sampler_num = 1;
374 for (unsigned i = phases[phase].start; i < phases[phase].end; ++i) {
376 sprintf(effect_id, "eff%d", i);
377 effects[i]->set_uniforms(phases[phase].glsl_program_num, effect_id, &sampler_num);
383 glTexCoord2f(0.0f, 1.0f);
384 glVertex2f(0.0f, 0.0f);
386 glTexCoord2f(1.0f, 1.0f);
387 glVertex2f(1.0f, 0.0f);
389 glTexCoord2f(1.0f, 0.0f);
390 glVertex2f(1.0f, 1.0f);
392 glTexCoord2f(0.0f, 0.0f);
393 glVertex2f(0.0f, 1.0f);
399 glActiveTexture(GL_TEXTURE0);
400 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);