wip extract to files

src/shaders.c

@@ -0,0 +1,74 @@
+#include <stddef.h>
+
+#include <linmath.h>
+
+#include "constants.h"
+#include "glfw.h"
+#include "types.h"
+
+// TODO split into smaller functions
+ShaderProgram init_program(File fragment_shader) {
+  ShaderProgram program = {};
+  GLint status_params;
+
+  glGenBuffers(1, &program.vertex_buffer);
+  glBindBuffer(GL_ARRAY_BUFFER, program.vertex_buffer);
+  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+  program.vertex_shader = glCreateShader(GL_VERTEX_SHADER);
+  glShaderSource(program.vertex_shader, 1, &vertex_shader_text, NULL);
+  glCompileShader(program.vertex_shader);
+
+  glGetShaderiv(program.vertex_shader, GL_COMPILE_STATUS, &status_params);
+  if (status_params == GL_FALSE) {
+    program.error = true;
+    // TODO use glGetShaderInfoLog( 	GLuint shader, GLsizei
+    // maxLength, GLsizei *length, GLchar *infoLog);
+  }
+
+  program.fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
+  glShaderSource(program.fragment_shader, 1,
+                 (const GLchar *const *)&fragment_shader.content, NULL);
+  glCompileShader(program.fragment_shader);
+
+  glGetShaderiv(program.fragment_shader, GL_COMPILE_STATUS, &status_params);
+  if (status_params == GL_FALSE) {
+    program.error = true;
+  }
+
+  if (program.error) {
+    return program;
+  }
+
+  program.program = glCreateProgram();
+  glAttachShader(program.program, program.vertex_shader);
+  glAttachShader(program.program, program.fragment_shader);
+  glLinkProgram(program.program);
+
+  program.mvp_location = glGetUniformLocation(program.program, "mvp");
+  program.itime_location = glGetUniformLocation(program.program, "iTime");
+  program.ires_location = glGetUniformLocation(program.program, "iResolution");
+  program.vpos_location = glGetAttribLocation(program.program, "vPos");
+
+  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));
+
+  return program;
+}
+
+void update_program(ShaderProgram program, File fragment_shader) {
+  GLint status_params;
+  glShaderSource(program.fragment_shader, 1,
+                 (const GLchar *const *)&fragment_shader.content, NULL);
+  glCompileShader(program.fragment_shader);
+
+  glGetShaderiv(program.fragment_shader, GL_COMPILE_STATUS, &status_params);
+  if (status_params == GL_FALSE) {
+    fprintf(stderr, "Failed to compile shaders\n"); // TODO add info
+    return;
+  }
+  glLinkProgram(program.program);
+}