working framebuffers, textures and feedback

README.md

@@ -100,11 +100,12 @@ make -f Makefile.dev release-arch
   - [x] fps in window title
   - [x] Clean code
 - [ ] Multi-stage shaders
-  - [ ] Test 2 stages with render to texture
+  - [x] Test 2 stages with render to texture
   - [ ] 2 in 2 fx 1 mix 1 fx layout
   - [ ] Include fragments with special directive
   - [ ] 16 input + 16 fx definition and selection (with param)
-  - [ ] Feedback texture
+  - [x] Feedback texture
+  - [ ] Free opengl memory
   - [ ] Clean code
 - [ ] Midi
   - [ ] Read Midi events

shaders/frag.glsl

@@ -2,15 +2,15 @@
 
 uniform float iTime;
 uniform vec2 iResolution;
-uniform sampler2D frame0;
 in vec2 vUV;
-layout(location = 0) out vec4 fragColor;
+out vec3 fragColor;
+uniform sampler2D frame0;
 
 void main() {
     vec2 uv0 = vUV.st;
     float ratio = iResolution.x / iResolution.y;
     vec2 uv1 = (uv0 - .5) * vec2(ratio, 1);
     vec3 color = vec3(vUV, sin(iTime * 0.5) * 0.5 + 0.5);
-    color *= 1 - step(cos(iTime) * 0.1 + 0.5,length(uv1));
+    color *= 1 - step(cos(iTime) * 0.1 + 0.4, length(uv1));
-    fragColor = vec4(color, 1.0);
+    fragColor = color + texture(frame0, vUV - 0.01).xyz * 0.5;
 }

src/config.h

@@ -9,12 +9,8 @@
 #define VERSION "(dev)"
 #endif
 
-#ifndef FRAMEBUFFER_IDS
-#define FRAMEBUFFER_IDS {0, 1, 2, 3, 4, 5, 6, 7}
-#endif
-
 #ifndef BUFFER_COUNT
-#define BUFFER_COUNT 8
+#define BUFFER_COUNT 1
 #endif
 
 #endif

src/constants.h

@@ -5,7 +5,8 @@
 
 static char *vertex_shader_text =
     "#version 460\n"
-    "uniform mat4 mvp;\n"
+    "const mat4 mvp = "
+    "{{2.,0.,0.,0.},{0.,2.,0.,0.},{0.,0.,2.,0.},{-1.,-1.,1.,1.}};\n"
     "in vec2 vPos;\n"
     "out vec2 vUV;\n"
     "void main()\n"
@@ -18,10 +19,10 @@ static char *output_fragment_shader_text =
     "#version 460\n"
     "in vec2 vUV;\n"
     "out vec4 fragColor;\n"
-    "uniform sampler2D frame0\n"
+    "uniform sampler2D frame0;\n"
     "void main()\n"
     "{\n"
-    "    fragColor = vec4(texture(frame0, vUV).xyz, 1.0);\n"
+    "    fragColor = texture(frame0, vUV);\n"
     "}\n";
 
 static const Vertex vertices[6] = {{{0.0f, 0.0f}}, {{0.0f, 1.0f}},

src/shaders.c

@@ -34,65 +34,44 @@ bool compile_shader(GLuint shader_id, char *name, char *source_code) {
 
 ShaderProgram init_program(File fragment_shader, Context context) {
   int i, j;
-  GLenum draw_buffers[BUFFER_COUNT];
   char uniform_name[32];
 
+  ShaderProgram program = {.error = false,
+                           .last_width = context.width,
+                           .last_height = context.height};
+
+  // create empty textures
+  glGenTextures(BUFFER_COUNT, program.textures);
+
   for (i = 0; i < BUFFER_COUNT; i++) {
-    draw_buffers[i] = GL_COLOR_ATTACHMENT0 + i;
+    glActiveTexture(GL_TEXTURE0 + i);
-  }
-
-  ShaderProgram program = {.error = false, .frame_buffers = FRAMEBUFFER_IDS};
-
-  // create vertex buffer and setup vertices
-  glGenBuffers(1, &program.vertex_buffer);
-  glBindBuffer(GL_ARRAY_BUFFER, program.vertex_buffer);
-  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-
-  // create framebuffers and textures
-  glGenTextures(1, program.textures);
-  glGenFramebuffers(BUFFER_COUNT, program.frame_buffers);
-  glGenRenderbuffers(BUFFER_COUNT, program.render_buffers);
-  for (i = 0; i < BUFFER_COUNT; i++) {
-    glTextureParameteri(program.textures[i], GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glTextureParameteri(program.textures[i], GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glTextureParameteri(program.textures[i], GL_TEXTURE_WRAP_S,
-                        GL_CLAMP_TO_EDGE);
-    glTextureParameteri(program.textures[i], GL_TEXTURE_WRAP_T,
-                        GL_CLAMP_TO_EDGE);
 
     glBindTexture(GL_TEXTURE_2D, program.textures[i]);
 
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, context.width, context.height, 0,
                  GL_RGB, GL_UNSIGNED_BYTE, 0);
 
-    glBindRenderbuffer(GL_RENDERBUFFER, program.render_buffers[i]);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, context.width,
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-                          context.height);
+  }
-    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
-                              GL_RENDERBUFFER, program.render_buffers[i]);
 
+  // create frame buffers
+  glGenFramebuffers(BUFFER_COUNT, program.frame_buffers);
+
+  for (i = 0; i < BUFFER_COUNT; i++) {
     glBindFramebuffer(GL_FRAMEBUFFER, program.frame_buffers[i]);
 
-    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
-                              GL_RENDERBUFFER, program.render_buffers[i]);
+                           program.textures[i], 0);
-
-    for (j = 0; j < BUFFER_COUNT; j++) {
-      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + j,
-                             GL_TEXTURE_2D, program.textures[j], 0);
-    }
-
-    glDrawBuffers(BUFFER_COUNT, draw_buffers);
 
     if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
-      log_error("Framebuffer %d is KO: %x", i,
+      log_error("Framebuffer %d is KO: %x", i + 1,
                 glCheckFramebufferStatus(GL_FRAMEBUFFER));
       program.error = true;
       return program;
     }
   }
 
-  glBindFramebuffer(GL_FRAMEBUFFER, 0);
-
   // compile vertex shader
   program.vertex_shader = glCreateShader(GL_VERTEX_SHADER);
   program.error |= !compile_shader(
@@ -112,75 +91,108 @@ ShaderProgram init_program(File fragment_shader, Context context) {
     return program;
   }
 
-  // create and link full shader program
+  // create vertex buffer and setup vertices
-  program.program = glCreateProgram();
+  glGenBuffers(1, &program.vertex_buffer);
-  glAttachShader(program.program, program.vertex_shader);
+  glBindBuffer(GL_ARRAY_BUFFER, program.vertex_buffer);
-  glAttachShader(program.program, program.fragment_shader);
+  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-  glAttachShader(program.program, program.output_fragment_shader);
-  glLinkProgram(program.program);
 
-  // create uniforms pointers
+  // create vertex array
-  program.mvp_location = glGetUniformLocation(program.program, "mvp");
-  program.itime_location = glGetUniformLocation(program.program, "iTime");
-  program.ires_location = glGetUniformLocation(program.program, "iResolution");
-
-  for (i = 0; i < BUFFER_COUNT; i++) {
-    sprintf(uniform_name, "frame%d", i);
-    program.frames_location[i] =
-        glGetUniformLocation(program.program, uniform_name);
-  }
-
-  // create attribute pointer
-  program.vpos_location = glGetAttribLocation(program.program, "vPos");
-
-  // create vertex array and bind to vPos attribute
   glGenVertexArrays(1, &program.vertex_array);
   glBindVertexArray(program.vertex_array);
-  glEnableVertexAttribArray(program.vpos_location);
-  glVertexAttribPointer(program.vpos_location, 2, GL_FLOAT, GL_FALSE,
-                        sizeof(Vertex), (void *)offsetof(Vertex, pos));
 
-  log_success("Program initialized");
+  // create and link full shader program
+  for (i = 0; i < BUFFER_COUNT + 1; i++) {
+    program.programs[i] = glCreateProgram();
+    glAttachShader(program.programs[i], program.vertex_shader);
+    if (i == BUFFER_COUNT) {
+      glAttachShader(program.programs[i], program.output_fragment_shader);
+    } else {
+      // TODO add others
+      glAttachShader(program.programs[i], program.fragment_shader);
+    }
+    glLinkProgram(program.programs[i]);
+
+    // create uniforms pointers
+    if (i != BUFFER_COUNT) {
+      program.itime_locations[i] =
+          glGetUniformLocation(program.programs[i], "iTime");
+      program.ires_locations[i] =
+          glGetUniformLocation(program.programs[i], "iResolution");
+    }
+
+    for (j = 0; j < BUFFER_COUNT; j++) {
+      sprintf(uniform_name, "frame%d", j);
+      program.frames_locations[i][j] =
+          glGetUniformLocation(program.programs[i], uniform_name);
+    }
+
+    // create attribute pointer
+    program.vpos_locations[i] =
+        glGetAttribLocation(program.programs[i], "vPos");
+
+    glEnableVertexAttribArray(program.vpos_locations[i]);
+    glVertexAttribPointer(program.vpos_locations[i], 2, GL_FLOAT, GL_FALSE,
+                          sizeof(Vertex), (void *)offsetof(Vertex, pos));
+
+    log_success("Program %d initialized", i);
+  }
 
   return program;
 }
 
 void update_program(ShaderProgram program, File fragment_shader) {
   bool result;
+  int i;
 
   result = compile_shader(program.fragment_shader, fragment_shader.path,
                           fragment_shader.content);
 
   if (result) {
     // re-link program
-    glLinkProgram(program.program);
+    for (i = 0; i < BUFFER_COUNT; i++) {
+      glLinkProgram(program.programs[i]);
+    }
 
-    log_success("Program updated");
+    log_success("Programs updated");
   }
 }
 
 void apply_program(ShaderProgram program, Context context) {
-  mat4x4 m, p, mvp;
+  int i, j;
 
-  // update viewport
+  if (context.width != program.last_width ||
-  glViewport(0, 0, context.width, context.height);
+      context.height != program.last_height) {
-  // clear buffer
+    glViewport(0, 0, context.width, context.height);
-  glClear(GL_COLOR_BUFFER_BIT);
 
-  // create model-view-projection matrix
+    for (i = 0; i < BUFFER_COUNT; i++) {
-  mat4x4_identity(m);
+      glActiveTexture(GL_TEXTURE0 + i);
-  mat4x4_ortho(p, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f);
+      glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, context.width, context.height, 0,
-  mat4x4_mul(mvp, p, m);
+                   GL_RGB, GL_UNSIGNED_BYTE, 0);
+    }
+  }
 
   vec2 resolution = {(float)context.width, (float)context.height};
 
-  // update uniforms
+  for (i = 0; i < BUFFER_COUNT + 1; i++) {
-  glUseProgram(program.program);
+    glUseProgram(program.programs[i]);
-  glUniformMatrix4fv(program.mvp_location, 1, GL_FALSE, (const GLfloat *)&mvp);
-  glUniform1f(program.itime_location, (const GLfloat)context.time);
-  glUniform2fv(program.ires_location, 1, (const GLfloat *)&resolution);
 
-  // start vertex handling
+    if (i == BUFFER_COUNT) {
-  glBindVertexArray(program.vertex_array);
+      glBindFramebuffer(GL_FRAMEBUFFER, 0);
-  glDrawArrays(GL_TRIANGLES, 0, 6);
+
-}
+      glClear(GL_COLOR_BUFFER_BIT);
+    } else {
+      glBindFramebuffer(GL_FRAMEBUFFER, program.frame_buffers[0]);
+
+      glUniform1f(program.itime_locations[i], (const GLfloat)context.time);
+      glUniform2fv(program.ires_locations[i], 1, (const GLfloat *)&resolution);
+    }
+
+    for (j = 0; j < BUFFER_COUNT; j++) {
+      glUniform1i(program.frames_locations[i][j], j);
+    }
+
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+  }
+}
+
+// TODO clean buffers from opengl memories

src/types.h

@@ -30,23 +30,24 @@ typedef struct File {
 typedef struct ShaderProgram {
   bool error;
 
-  GLuint program;
+  int last_width;
+  int last_height;
+
+  GLuint programs[BUFFER_COUNT + 1];
 
   GLuint vertex_shader;
   GLuint fragment_shader;
   GLuint output_fragment_shader;
 
-  GLuint mvp_location;
+  GLuint itime_locations[BUFFER_COUNT];
-  GLuint itime_location;
+  GLuint ires_locations[BUFFER_COUNT];
-  GLuint ires_location;
+  GLuint frames_locations[BUFFER_COUNT + 1][BUFFER_COUNT];
-  GLuint frames_location[BUFFER_COUNT];
+  GLuint vpos_locations[BUFFER_COUNT + 1];
 
   GLuint vertex_buffer;
   GLuint vertex_array;
-  GLuint vpos_location;
 
   GLuint frame_buffers[BUFFER_COUNT];
-  GLuint render_buffers[BUFFER_COUNT];
   GLuint textures[BUFFER_COUNT];
 } ShaderProgram;