#include "render/texture.h"

#include <stdlib.h>

GLuint Texture_createR8(int width, int height) {
    GLuint tex;
    glGenTextures(1, &tex);
    glBindTexture(GL_TEXTURE_2D, tex);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, NULL);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glBindTexture(GL_TEXTURE_2D, 0);
    return tex;
}

void Texture_updateR8(GLuint texture, int width, int height, const unsigned char *data) {
    glBindTexture(GL_TEXTURE_2D, texture);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GL_RED, GL_UNSIGNED_BYTE, data);
    glBindTexture(GL_TEXTURE_2D, 0);
}

GLuint Texture_createRGBA8(int width, int height) {
    unsigned char *zero = calloc((size_t)width * (size_t)height, 4);
    if (!zero) return 0;
    GLuint tex;
    glGenTextures(1, &tex);
    glBindTexture(GL_TEXTURE_2D, tex);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, zero);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glBindTexture(GL_TEXTURE_2D, 0);
    free(zero);
    return tex;
}

void Texture_updateRGBA8(GLuint texture, int x, int y, int width, int height, const unsigned char *data) {
    glBindTexture(GL_TEXTURE_2D, texture);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data);
    glBindTexture(GL_TEXTURE_2D, 0);
}

void Texture_destroy(GLuint *texture) {
    if (*texture) glDeleteTextures(1, texture);
    *texture = 0;
}