/*
 * Copyright (C) 2018 Tomasz Kramkowski <tk@the-tk.com>
 * SPDX-License-Identifier: MIT
 */
#include <assert.h>
#include <png.h>
#include <stdlib.h>

#include "eprintf.h"
#include "tex.h"

GLuint png2tex(FILE *f)
{
	png_image pi = { .version = PNG_IMAGE_VERSION };
	unsigned char *data;
	size_t size;
	GLuint id;

	assert(f != NULL);

	png_image_begin_read_from_stdio(&pi, f);
	pi.format = PNG_FORMAT_RGB;
	size = sizeof *data * 3 * pi.width * pi.height;
	data = emalloc(size);
	png_image_finish_read(&pi, NULL, data, size / pi.height, NULL);

	gl_tex_gen(1, &id);
	gl_tex_bind(GL_TEXTURE_2D, id);
	gl_tex_parami(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	gl_tex_parami(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
	gl_tex_parami(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
	gl_tex_parami(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
	gl_tex_img2d(GL_TEXTURE_2D, 0, GL_RGB, pi.width, pi.height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
	gl_tex_genmip(GL_TEXTURE_2D);

	free(data);
	png_image_free(&pi);

	return id;
}