gbuffer.c

#include "gbuffer.h"

/* gbuffer_t type
typedef struct gbuffer_t {
    unsigned int id;
    int width;
    int height;
    Texture2D color;
    Texture2D normal;
    Texture2D position;
} gbuffer_t;
*/

void gbuffer_init(gbuffer_t* gbuffer, int width, int height)
{
    gbuffer->id = 0;
    gbuffer->width = width;
    gbuffer->height = height;
    
    gbuffer->color.id = 0;
    gbuffer->color.width = width;
    gbuffer->color.height = height;
    gbuffer->color.format = UNCOMPRESSED_R8G8B8A8;
    gbuffer->color.mipmaps = 1;
    
    gbuffer->normal.id = 0;
    gbuffer->normal.width = width;
    gbuffer->normal.height = height;
    gbuffer->normal.format = UNCOMPRESSED_R8G8B8A8;
    gbuffer->normal.mipmaps = 1;
    
    gbuffer->position.id = 0;
    gbuffer->position.width = width;
    gbuffer->position.height = height;
    gbuffer->position.format = UNCOMPRESSED_R8G8B8A8;
    gbuffer->position.mipmaps = 1;
    
    glGenFramebuffers(1, &gbuffer->id);
    glBindFramebuffer(GL_FRAMEBUFFER, gbuffer->id);
    
    glGenTextures(1, &gbuffer->color.id);
    glBindTexture(GL_TEXTURE_2D, gbuffer->color.id);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, gbuffer->color.id, 0);
    
    // it's not this
    unsigned int buffers[1] = {GL_COLOR_ATTACHMENT0};
    glDrawBuffers(1, buffers);
    
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
    
}

void gbuffer_begin(gbuffer_t* gbuffer)
{
    rlglDraw();
    
    rlEnableRenderTexture(gbuffer->id);
    
    rlClearScreenBuffers();
    
    rlViewport(0, 0, gbuffer->width, gbuffer->height);
    
    rlMatrixMode(RL_PROJECTION);
    rlLoadIdentity();
    
    rlOrtho(0, gbuffer->width, gbuffer->height, 0, 0, 1);
    
    rlMatrixMode(RL_MODELVIEW);
    rlLoadIdentity();
}

void gbuffer_end()
{
    rlglDraw();
    
    rlDisableRenderTexture();
    
    rlViewport(0, 0, GetScreenWidth(), GetScreenHeight());
    
    rlMatrixMode(RL_PROJECTION);
    rlLoadIdentity();
    
    rlOrtho(0, GetScreenWidth(), GetScreenHeight(), 0, 0, 1);
    
    rlMatrixMode(RL_MODELVIEW);
    rlLoadIdentity();
}

void gbuffer_free(gbuffer_t* gbuffer)
{
    glDeleteFramebuffers(1, &gbuffer->id);
    glDeleteTextures(1, &gbuffer->color.id);
    glDeleteTextures(1, &gbuffer->normal.id);
    glDeleteTextures(1, &gbuffer->position.id);
}