Files
forge-steel/src/shaders.c
T
2025-09-13 15:38:52 +02:00

75 lines
2.5 KiB
C

#include <stddef.h>
#include <stdio.h>
#include <glad/gl.h>
#include <linmath.h>
#include "constants.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);
}