c-engine/src/shader.c

79 lines
2.7 KiB
C

#include "shader.h"
#include "SDL3/SDL_iostream.h"
#include "SDL3/SDL_log.h"
#include "arena_allocator.h"
#include <GLES2/gl2.h>
wn_shader *wn_shader_init(Arena *arena,
wn_shader_code_location shader_code_location) {
wn_shader *shader = arena_alloc(arena, sizeof(wn_shader));
*shader = (wn_shader){.shaderProgram = 0, .success = false};
const char *vertexShaderSource =
SDL_LoadFile(shader_code_location.vertex_shader_source_path, NULL);
const char *fragmentShaderSource =
SDL_LoadFile(shader_code_location.fragment_shader_source_path, NULL);
// vertex shader
unsigned int vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
// check for shader compile errors
int success;
char infoLog[512];
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
if (!success) {
glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"Failed to compile vertex shader: %s", infoLog);
return shader;
}
// fragment shader
unsigned int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glCompileShader(fragmentShader);
// check for shader compile errors
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
if (!success) {
glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"Failed to compile fragment shader: %s", infoLog);
return shader;
}
// Free source code memory
SDL_free((void *)vertexShaderSource);
SDL_free((void *)fragmentShaderSource);
// link shaders
unsigned int shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
// check for linking errors
glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
if (!success) {
glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
"Failed to link shader program: %s", infoLog);
return shader;
}
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
shader->shaderProgram = shaderProgram;
shader->success = true;
arena_deinit_task_push(arena, (ArenaDeinitTask){.func_ptr = *wn_shader_deinit,
.func_param = shader,
.next = NULL});
return shader;
}
void wn_shader_deinit(void *shader) {
wn_shader *cast_shader = (wn_shader *)shader;
glDeleteProgram(cast_shader->shaderProgram);
}