/// H File Follows

/**
 * Copyright (c) 2023 Jonathan Metzgar
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include <SDL2/SDL_opengl.h>
#include <SDL2/SDL_opengl_glext.h>
#include "object.h"

struct GfFunction_t
{
    Object_t self;
} GfFunction_t, *GfFunction;

typedef struct GfPipelineState_t
{
    Object_t self;

    GLuint program;
} GfPipelineState_t, *GfPipelineState;

struct GfBuffer_t
{

} GfBuffer_t, *GfBuffer;

GfPipelineState GfNewPipeline(const char *vertSource, const char *fragSource);
void GfUsePipeline(GfPipelineState pso);


/// C File follows


/**
 * Copyright (c) 2023 Jonathan Metzgar
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */
#include <stdio.h>

#define GL_SILENCE_DEPRECATION 1
#include <OpenGL/gl3.h>
#include "goldfish.h"

void Log(const char *label, const char *str)
{
    fprintf(stderr, "%s: %s\n", label, str);
}

GLuint CompileShader(const char *source, GLenum type)
{
    if (source == NULL)
        return 0;
    GLuint shader = glCreateShader(type);
    glShaderSource(shader, 1, &source, NULL);
    glCompileShader(shader);
    GLint status;
    glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
    if (status != GL_TRUE)
    {
        GLchar infoLog[1024];
        GLsizei length;
        glGetShaderInfoLog(shader, 1024, &length, infoLog);
        Log("error", infoLog);
        glDeleteShader(shader);
        return 0;
    }
    return shader;
}

GLuint CompileProgram(const char *vertSource, const char *fragSource)
{
    GLuint vs = CompileShader(vertSource, GL_VERTEX_SHADER);
    GLuint fs = CompileShader(fragSource, GL_FRAGMENT_SHADER);
    GLuint program = glCreateProgram();
    if (vs != 0)
    {
        glAttachShader(program, vs);
    }
    if (fs != 0)
    {
        glAttachShader(program, fs);
    }
    glLinkProgram(program);
    GLint status;
    glGetProgramiv(program, GL_LINK_STATUS, &status);
    if (status != GL_TRUE)
    {
        GLchar infoLog[1024];
        GLsizei length;
        glGetProgramInfoLog(program, 1024, &length, infoLog);
        Log("error", infoLog);
        glDeleteProgram(program);
        program = 0;
    }
    glDeleteShader(vs);
    glDeleteShader(fs);
    return program;
}

GfPipelineState GfNewPipeline(const char *vertSource, const char *fragSource)
{
    GfPipelineState pso = (GfPipelineState)allocObject(sizeof(GfPipelineState_t));
    
    pso->program = CompileProgram(vertSource, fragSource);

    return pso;
}

void GfUsePipeline(GfPipelineState pso)
{
    if (pso == NULL)
    {
        return;
    }
    glUseProgram(pso->program);
}