]> git.sesse.net Git - movit/blobdiff - effect_chain.cpp
Try to adjust the mip levels to get box blur for free as needed.
[movit] / effect_chain.cpp
index 5c1ba69e64a71ad65fe34ad3d7c53d76f4471fd9..899c6a3f4ca9335e518cd3939a452cafe6955801 100644 (file)
@@ -14,8 +14,9 @@
 #include "lift_gamma_gain_effect.h"
 #include "colorspace_conversion_effect.h"
 #include "saturation_effect.h"
+#include "mirror_effect.h"
 #include "vignette_effect.h"
-#include "texture_enum.h"
+#include "blur_effect.h"
 
 EffectChain::EffectChain(unsigned width, unsigned height)
        : width(width), height(height), use_srgb_texture_format(false), finalized(false) {}
@@ -45,8 +46,12 @@ Effect *instantiate_effect(EffectId effect)
                return new LiftGammaGainEffect();
        case EFFECT_SATURATION:
                return new SaturationEffect();
+       case EFFECT_MIRROR:
+               return new MirrorEffect();
        case EFFECT_VIGNETTE:
                return new VignetteEffect();
+       case EFFECT_BLUR:
+               return new BlurEffect();
        }
        assert(false);
 }
@@ -86,10 +91,6 @@ Effect *EffectChain::add_effect(EffectId effect_id)
                normalize_to_srgb();
        }
 
-       // not handled yet
-       assert(!effect->needs_many_samples());
-       assert(!effect->needs_mipmaps());
-
        effects.push_back(effect);
        return effect;
 }
@@ -135,30 +136,11 @@ std::string replace_prefix(const std::string &text, const std::string &prefix)
        return output;
 }
 
-void EffectChain::finalize()
+EffectChain::Phase EffectChain::compile_glsl_program(unsigned start_index, unsigned end_index)
 {
-       if (current_color_space != output_format.color_space) {
-               ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
-               colorspace_conversion->set_int("source_space", current_color_space);
-               colorspace_conversion->set_int("destination_space", output_format.color_space);
-               effects.push_back(colorspace_conversion);
-               current_color_space = output_format.color_space;
-       }
-
-       if (current_gamma_curve != output_format.gamma_curve) {
-               if (current_gamma_curve != GAMMA_LINEAR) {
-                       normalize_to_linear_gamma();
-               }
-               assert(current_gamma_curve == GAMMA_LINEAR);
-               GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
-               gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
-               effects.push_back(gamma_conversion);
-               current_gamma_curve = output_format.gamma_curve;
-       }
-
-       std::string frag_shader = read_file("header.glsl");
-
-       for (unsigned i = 0; i < effects.size(); ++i) {
+       bool input_needs_mipmaps = false;
+       std::string frag_shader = read_file("header.frag");
+       for (unsigned i = start_index; i < end_index; ++i) {
                char effect_id[256];
                sprintf(effect_id, "eff%d", i);
        
@@ -171,12 +153,14 @@ void EffectChain::finalize()
                frag_shader += "#undef LAST_INPUT\n";
                frag_shader += std::string("#define LAST_INPUT ") + effect_id + "\n";
                frag_shader += "\n";
+
+               input_needs_mipmaps |= effects[i]->needs_mipmaps();
        }
-       frag_shader.append(read_file("footer.glsl"));
+       frag_shader.append(read_file("footer.frag"));
        printf("%s\n", frag_shader.c_str());
        
-       glsl_program_num = glCreateProgram();
-       GLuint vs_obj = compile_shader(read_file("vs.glsl"), GL_VERTEX_SHADER);
+       GLuint glsl_program_num = glCreateProgram();
+       GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
        GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
        glAttachShader(glsl_program_num, vs_obj);
        check_error();
@@ -185,7 +169,68 @@ void EffectChain::finalize()
        glLinkProgram(glsl_program_num);
        check_error();
 
-       // Translate the format to OpenGL's enums.
+       Phase phase;
+       phase.glsl_program_num = glsl_program_num;
+       phase.input_needs_mipmaps = input_needs_mipmaps;
+       phase.start = start_index;
+       phase.end = end_index;
+
+       return phase;
+}
+
+void EffectChain::finalize()
+{
+       // Add normalizers to get the output format right.
+       if (current_color_space != output_format.color_space) {
+               ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
+               colorspace_conversion->set_int("source_space", current_color_space);
+               colorspace_conversion->set_int("destination_space", output_format.color_space);
+               effects.push_back(colorspace_conversion);
+               current_color_space = output_format.color_space;
+       }
+       if (current_gamma_curve != output_format.gamma_curve) {
+               if (current_gamma_curve != GAMMA_LINEAR) {
+                       normalize_to_linear_gamma();
+               }
+               assert(current_gamma_curve == GAMMA_LINEAR);
+               GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
+               gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
+               effects.push_back(gamma_conversion);
+               current_gamma_curve = output_format.gamma_curve;
+       }
+
+       // Construct the GLSL programs. We end a program every time we come
+       // to an effect marked as "needs many samples" (ie. "please let me
+       // sample directly from a texture, with no arithmetic in-between"),
+       // and of course at the end.
+       unsigned start = 0;
+       for (unsigned i = 0; i < effects.size(); ++i) {
+               if (effects[i]->needs_many_samples() && i != start) {
+                       phases.push_back(compile_glsl_program(start, i));
+                       start = i;
+               }
+       }
+       phases.push_back(compile_glsl_program(start, effects.size()));
+
+       // If we have more than one phase, we need intermediate render-to-texture.
+       // Construct an FBO, and then as many textures as we need.
+       if (phases.size() > 1) {
+               glGenFramebuffers(1, &fbo);
+
+               unsigned num_textures = std::max<int>(phases.size() - 1, 2);
+               glGenTextures(num_textures, temp_textures);
+
+               unsigned char *empty = new unsigned char[width * height * 4];
+               for (unsigned i = 0; i < num_textures; ++i) {
+                       glBindTexture(GL_TEXTURE_2D, temp_textures[i]);
+                       check_error();
+                       glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, empty);
+                       check_error();
+               }
+               delete[] empty;
+       }
+       
+       // Translate the input format to OpenGL's enums.
        GLenum internal_format;
        if (use_srgb_texture_format) {
                internal_format = GL_SRGB8;
@@ -208,7 +253,7 @@ void EffectChain::finalize()
                assert(false);
        }
 
-       // Create PBO to hold the texture, and then the texture itself.
+       // Create PBO to hold the texture holding the input image, and then the texture itself.
        glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
        check_error();
        glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, width * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
@@ -218,7 +263,11 @@ void EffectChain::finalize()
        memset(mapped_pbo, 0, width * height * bytes_per_pixel);
        glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
        
-       glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
+       glGenTextures(1, &source_image_num);
+       check_error();
+       glBindTexture(GL_TEXTURE_2D, source_image_num);
+       check_error();
+       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        check_error();
        glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
        check_error();
@@ -243,25 +292,18 @@ void EffectChain::render_to_screen(unsigned char *src)
        // Re-upload the texture from the PBO.
        glActiveTexture(GL_TEXTURE0);
        check_error();
-       glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
+       glBindTexture(GL_TEXTURE_2D, source_image_num);
        check_error();
        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
        check_error();
-       glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
+       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        check_error();
-
-       glUseProgram(glsl_program_num);
+       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        check_error();
-
+       glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
        check_error();
-       glUniform1i(glGetUniformLocation(glsl_program_num, "input_tex"), 0);
-
-       for (unsigned i = 0; i < effects.size(); ++i) {
-               char effect_id[256];
-               sprintf(effect_id, "eff%d", i);
-               effects[i]->set_uniforms(glsl_program_num, effect_id);
-       }
 
+       // Basic state.
        glDisable(GL_BLEND);
        check_error();
        glDisable(GL_DEPTH_TEST);
@@ -276,20 +318,81 @@ void EffectChain::render_to_screen(unsigned char *src)
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
 
-       glBegin(GL_QUADS);
+       if (phases.size() > 1) {
+               glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+               check_error();
+       }
 
-       glTexCoord2f(0.0f, 1.0f);
-       glVertex2f(0.0f, 0.0f);
+       for (unsigned phase = 0; phase < phases.size(); ++phase) {
+               // Set up inputs and outputs for this phase.
+               if (phase == 0) {
+                       // First phase reads from the input texture (which is already bound).
+               } else {
+                       glBindTexture(GL_TEXTURE_2D, temp_textures[(phase + 1) % 2]);
+                       check_error();
+               }
+               if (phases[phase].input_needs_mipmaps) {
+                       glGenerateMipmap(GL_TEXTURE_2D);
+                       check_error();
+                       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+                       check_error();
+               } else {
+                       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+                       check_error();
+               }
 
-       glTexCoord2f(1.0f, 1.0f);
-       glVertex2f(1.0f, 0.0f);
+               if (phase == phases.size() - 1) {
+                       // Last phase goes directly to the screen.
+                       glBindFramebuffer(GL_FRAMEBUFFER, 0);
+                       check_error();
+               } else {
+                       glFramebufferTexture2D(
+                               GL_FRAMEBUFFER,
+                               GL_COLOR_ATTACHMENT0,
+                               GL_TEXTURE_2D,
+                               temp_textures[phase % 2],
+                               0);
+               }
 
-       glTexCoord2f(1.0f, 0.0f);
-       glVertex2f(1.0f, 1.0f);
+               // We have baked an upside-down transform into the quad coordinates,
+               // since the typical graphics program will have the origin at the upper-left,
+               // while OpenGL uses lower-left. In the next ones, however, the origin
+               // is all right, and we need to reverse that.
+               if (phase == 1) {
+                       glTranslatef(0.0f, 1.0f, 0.0f);
+                       glScalef(1.0f, -1.0f, 1.0f);
+               }
 
-       glTexCoord2f(0.0f, 0.0f);
-       glVertex2f(0.0f, 1.0f);
+               // Give the required parameters to all the effects.
+               glUseProgram(phases[phase].glsl_program_num);
+               check_error();
 
-       glEnd();
-       check_error();
+               glUniform1i(glGetUniformLocation(phases[phase].glsl_program_num, "input_tex"), 0);
+               check_error();
+
+               unsigned sampler_num = 1;
+               for (unsigned i = phases[phase].start; i < phases[phase].end; ++i) {
+                       char effect_id[256];
+                       sprintf(effect_id, "eff%d", i);
+                       effects[i]->set_uniforms(phases[phase].glsl_program_num, effect_id, &sampler_num);
+               }
+
+               // Now draw!
+               glBegin(GL_QUADS);
+
+               glTexCoord2f(0.0f, 1.0f);
+               glVertex2f(0.0f, 0.0f);
+
+               glTexCoord2f(1.0f, 1.0f);
+               glVertex2f(1.0f, 0.0f);
+
+               glTexCoord2f(1.0f, 0.0f);
+               glVertex2f(1.0f, 1.0f);
+
+               glTexCoord2f(0.0f, 0.0f);
+               glVertex2f(0.0f, 1.0f);
+
+               glEnd();
+               check_error();
+       }
 }