Files
ghostland-game/shader.cpp

83 lines
2.3 KiB
C++

#include <stdio.h>
#include <stdlib.h>
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include "shader.h"
int create_shader(const char *filename, int shadertype) {
FILE* fp = fopen(filename, "r");
if (!fp) {
printf("failed to open vertex shader!\n");
return -1;
}
fseek(fp, 0L, SEEK_END);
unsigned int buffer_sz = ftell(fp);
rewind(fp);
char *buffer = (char *)calloc(sizeof(char), buffer_sz + 1);
if (fread(buffer, buffer_sz, 1, fp) != 1) {
printf("failed to read vertex shader!\n");
return -1;
}
fclose(fp);
int shader = glCreateShader(shadertype);
glShaderSource(shader, 1, &buffer, NULL);
free(buffer);
glCompileShader(shader);
int success;
glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
if (!success) {
char info_log[1024];
glGetShaderInfoLog(shader, 1024, NULL, info_log);
printf("Shader compile error for %s: %s\n", filename, info_log);
glfwTerminate();
return -1;
}
return shader;
}
int create_shader_program(const char *vertex_filename, const char *fragment_filename) {
int vertex_shader = create_shader(vertex_filename, GL_VERTEX_SHADER);
if (vertex_shader < 0) {
return -1;
}
int fragment_shader = create_shader(fragment_filename, GL_FRAGMENT_SHADER);
if (fragment_shader < 0) {
return -1;
}
int program = glCreateProgram();
glAttachShader(program, vertex_shader);
glAttachShader(program, fragment_shader);
glLinkProgram(program);
int success;
glGetProgramiv(program, GL_LINK_STATUS, &success);
if (!success) {
char infoLog[1024];
glGetProgramInfoLog(program, 1024, NULL, infoLog);
printf("Shader wall_program link error: %s\n", infoLog);
return -1;
}
glDeleteShader(vertex_shader);
glDeleteShader(fragment_shader);
return program;
}
void set_uniform(int program, const char *key, float value) {
glUniform1f(glGetUniformLocation(program, key), value);
}
void set_uniform(int program, const char *key, const glm::vec3 &value) {
glUniform3fv(glGetUniformLocation(program, key), 1, &value[0]);
}
void set_uniform(int program, const char *key, const glm::mat4 &value) {
glUniformMatrix4fv(glGetUniformLocation(program, key), 1, GL_FALSE, &value[0][0]);
}