5c1ba69e64a71ad65fe34ad3d7c53d76f4471fd9
[movit] / effect_chain.cpp
1 #define GL_GLEXT_PROTOTYPES 1
2
3 #include <stdio.h>
4 #include <string.h>
5 #include <assert.h>
6
7 #include <GL/gl.h>
8 #include <GL/glext.h>
9
10 #include "util.h"
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 "vignette_effect.h"
18 #include "texture_enum.h"
19
20 EffectChain::EffectChain(unsigned width, unsigned height)
21         : width(width), height(height), use_srgb_texture_format(false), finalized(false) {}
22
23 void EffectChain::add_input(const ImageFormat &format)
24 {
25         input_format = format;
26         current_color_space = format.color_space;
27         current_gamma_curve = format.gamma_curve;
28 }
29
30 void EffectChain::add_output(const ImageFormat &format)
31 {
32         output_format = format;
33 }
34         
35 Effect *instantiate_effect(EffectId effect)
36 {
37         switch (effect) {
38         case EFFECT_GAMMA_EXPANSION:
39                 return new GammaExpansionEffect();
40         case EFFECT_GAMMA_COMPRESSION:
41                 return new GammaCompressionEffect();
42         case EFFECT_COLOR_SPACE_CONVERSION:
43                 return new ColorSpaceConversionEffect();
44         case EFFECT_LIFT_GAMMA_GAIN:
45                 return new LiftGammaGainEffect();
46         case EFFECT_SATURATION:
47                 return new SaturationEffect();
48         case EFFECT_VIGNETTE:
49                 return new VignetteEffect();
50         }
51         assert(false);
52 }
53
54 void EffectChain::normalize_to_linear_gamma()
55 {
56         if (current_gamma_curve == GAMMA_sRGB) {
57                 // TODO: check if the extension exists
58                 use_srgb_texture_format = true;
59         } else {
60                 GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
61                 gamma_conversion->set_int("source_curve", current_gamma_curve);
62                 effects.push_back(gamma_conversion);
63         }
64         current_gamma_curve = GAMMA_LINEAR;
65 }
66
67 void EffectChain::normalize_to_srgb()
68 {
69         assert(current_gamma_curve == GAMMA_LINEAR);
70         ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
71         colorspace_conversion->set_int("source_space", current_color_space);
72         colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
73         effects.push_back(colorspace_conversion);
74         current_color_space = COLORSPACE_sRGB;
75 }
76
77 Effect *EffectChain::add_effect(EffectId effect_id)
78 {
79         Effect *effect = instantiate_effect(effect_id);
80
81         if (effect->needs_linear_light() && current_gamma_curve != GAMMA_LINEAR) {
82                 normalize_to_linear_gamma();
83         }
84
85         if (effect->needs_srgb_primaries() && current_color_space != COLORSPACE_sRGB) {
86                 normalize_to_srgb();
87         }
88
89         // not handled yet
90         assert(!effect->needs_many_samples());
91         assert(!effect->needs_mipmaps());
92
93         effects.push_back(effect);
94         return effect;
95 }
96
97 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
98 std::string replace_prefix(const std::string &text, const std::string &prefix)
99 {
100         std::string output;
101         size_t start = 0;
102
103         while (start < text.size()) {
104                 size_t pos = text.find("PREFIX(", start);
105                 if (pos == std::string::npos) {
106                         output.append(text.substr(start, std::string::npos));
107                         break;
108                 }
109
110                 output.append(text.substr(start, pos - start));
111                 output.append(prefix);
112                 output.append("_");
113
114                 pos += strlen("PREFIX(");
115         
116                 // Output stuff until we find the matching ), which we then eat.
117                 int depth = 1;
118                 size_t end_arg_pos = pos;
119                 while (end_arg_pos < text.size()) {
120                         if (text[end_arg_pos] == '(') {
121                                 ++depth;
122                         } else if (text[end_arg_pos] == ')') {
123                                 --depth;
124                                 if (depth == 0) {
125                                         break;
126                                 }
127                         }
128                         ++end_arg_pos;
129                 }
130                 output.append(text.substr(pos, end_arg_pos - pos));
131                 ++end_arg_pos;
132                 assert(depth == 0);
133                 start = end_arg_pos;
134         }
135         return output;
136 }
137
138 void EffectChain::finalize()
139 {
140         if (current_color_space != output_format.color_space) {
141                 ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
142                 colorspace_conversion->set_int("source_space", current_color_space);
143                 colorspace_conversion->set_int("destination_space", output_format.color_space);
144                 effects.push_back(colorspace_conversion);
145                 current_color_space = output_format.color_space;
146         }
147
148         if (current_gamma_curve != output_format.gamma_curve) {
149                 if (current_gamma_curve != GAMMA_LINEAR) {
150                         normalize_to_linear_gamma();
151                 }
152                 assert(current_gamma_curve == GAMMA_LINEAR);
153                 GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
154                 gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
155                 effects.push_back(gamma_conversion);
156                 current_gamma_curve = output_format.gamma_curve;
157         }
158
159         std::string frag_shader = read_file("header.glsl");
160
161         for (unsigned i = 0; i < effects.size(); ++i) {
162                 char effect_id[256];
163                 sprintf(effect_id, "eff%d", i);
164         
165                 frag_shader += "\n";
166                 frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
167                 frag_shader += replace_prefix(effects[i]->output_convenience_uniforms(), effect_id);
168                 frag_shader += replace_prefix(effects[i]->output_fragment_shader(), effect_id);
169                 frag_shader += "#undef PREFIX\n";
170                 frag_shader += "#undef FUNCNAME\n";
171                 frag_shader += "#undef LAST_INPUT\n";
172                 frag_shader += std::string("#define LAST_INPUT ") + effect_id + "\n";
173                 frag_shader += "\n";
174         }
175         frag_shader.append(read_file("footer.glsl"));
176         printf("%s\n", frag_shader.c_str());
177         
178         glsl_program_num = glCreateProgram();
179         GLuint vs_obj = compile_shader(read_file("vs.glsl"), GL_VERTEX_SHADER);
180         GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
181         glAttachShader(glsl_program_num, vs_obj);
182         check_error();
183         glAttachShader(glsl_program_num, fs_obj);
184         check_error();
185         glLinkProgram(glsl_program_num);
186         check_error();
187
188         // Translate the format to OpenGL's enums.
189         GLenum internal_format;
190         if (use_srgb_texture_format) {
191                 internal_format = GL_SRGB8;
192         } else {
193                 internal_format = GL_RGBA8;
194         }
195         if (input_format.pixel_format == FORMAT_RGB) {
196                 format = GL_RGB;
197                 bytes_per_pixel = 3;
198         } else if (input_format.pixel_format == FORMAT_RGBA) {
199                 format = GL_RGBA;
200                 bytes_per_pixel = 4;
201         } else if (input_format.pixel_format == FORMAT_BGR) {
202                 format = GL_BGR;
203                 bytes_per_pixel = 3;
204         } else if (input_format.pixel_format == FORMAT_BGRA) {
205                 format = GL_BGRA;
206                 bytes_per_pixel = 4;
207         } else {
208                 assert(false);
209         }
210
211         // Create PBO to hold the texture, and then the texture itself.
212         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
213         check_error();
214         glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, width * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
215         check_error();
216
217         void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
218         memset(mapped_pbo, 0, width * height * bytes_per_pixel);
219         glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
220         
221         glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
222         check_error();
223         glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
224         check_error();
225         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
226         check_error();
227
228         finalized = true;
229 }
230
231 void EffectChain::render_to_screen(unsigned char *src)
232 {
233         assert(finalized);
234
235         // Copy the pixel data into the PBO.
236         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
237         check_error();
238         void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
239         memcpy(mapped_pbo, src, width * height * bytes_per_pixel);
240         glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
241         check_error();
242
243         // Re-upload the texture from the PBO.
244         glActiveTexture(GL_TEXTURE0);
245         check_error();
246         glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
247         check_error();
248         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
249         check_error();
250         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
251         check_error();
252
253         glUseProgram(glsl_program_num);
254         check_error();
255
256         check_error();
257         glUniform1i(glGetUniformLocation(glsl_program_num, "input_tex"), 0);
258
259         for (unsigned i = 0; i < effects.size(); ++i) {
260                 char effect_id[256];
261                 sprintf(effect_id, "eff%d", i);
262                 effects[i]->set_uniforms(glsl_program_num, effect_id);
263         }
264
265         glDisable(GL_BLEND);
266         check_error();
267         glDisable(GL_DEPTH_TEST);
268         check_error();
269         glDepthMask(GL_FALSE);
270         check_error();
271
272         glMatrixMode(GL_PROJECTION);
273         glLoadIdentity();
274         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
275
276         glMatrixMode(GL_MODELVIEW);
277         glLoadIdentity();
278
279         glBegin(GL_QUADS);
280
281         glTexCoord2f(0.0f, 1.0f);
282         glVertex2f(0.0f, 0.0f);
283
284         glTexCoord2f(1.0f, 1.0f);
285         glVertex2f(1.0f, 0.0f);
286
287         glTexCoord2f(1.0f, 0.0f);
288         glVertex2f(1.0f, 1.0f);
289
290         glTexCoord2f(0.0f, 0.0f);
291         glVertex2f(0.0f, 1.0f);
292
293         glEnd();
294         check_error();
295 }