/*
 * This file is part of mpv.
 * Parts based on MPlayer code by Reimar Döffinger.
 *
 * mpv is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * mpv is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with mpv.  If not, see <http://www.gnu.org/licenses/>.
 *
 * You can alternatively redistribute this file and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 */

#ifndef MP_GL_UTILS_
#define MP_GL_UTILS_

#include "common.h"

struct mp_log;

void glCheckError(GL *gl, struct mp_log *log, const char *info);

int glFmt2bpp(GLenum format, GLenum type);
void glUploadTex(GL *gl, GLenum target, GLenum format, GLenum type,
                 const void *dataptr, int stride,
                 int x, int y, int w, int h, int slice);
void glClearTex(GL *gl, GLenum target, GLenum format, GLenum type,
                int x, int y, int w, int h, uint8_t val, void **scratch);

mp_image_t *glGetWindowScreenshot(GL *gl);

// print a multi line string with line numbers (e.g. for shader sources)
// log, lev: module and log level, as in mp_msg()
void mp_log_source(struct mp_log *log, int lev, const char *src);

struct gl_vao_entry {
    // used for shader / glBindAttribLocation
    const char *name;
    // glVertexAttribPointer() arguments
    int num_elems;      // size (number of elements)
    GLenum type;
    bool normalized;
    int offset;
};

struct gl_vao {
    GL *gl;
    GLuint vao;     // the VAO object, or 0 if unsupported by driver
    GLuint buffer;  // GL_ARRAY_BUFFER used for the data
    int stride;     // size of each element (interleaved elements are assumed)
    const struct gl_vao_entry *entries;
};

void gl_vao_init(struct gl_vao *vao, GL *gl, int stride,
                 const struct gl_vao_entry *entries);
void gl_vao_uninit(struct gl_vao *vao);
void gl_vao_bind(struct gl_vao *vao);
void gl_vao_unbind(struct gl_vao *vao);
void gl_vao_draw_data(struct gl_vao *vao, GLenum prim, void *ptr, size_t num);

struct fbotex {
    GL *gl;
    GLuint fbo;
    GLuint texture;
    GLenum iformat;
    GLenum tex_filter;
    int w, h;   // size of .texture
};

bool fbotex_init(struct fbotex *fbo, GL *gl, struct mp_log *log, int w, int h,
                 GLenum iformat);
void fbotex_uninit(struct fbotex *fbo);
bool fbotex_change(struct fbotex *fbo, GL *gl, struct mp_log *log, int w, int h,
                   GLenum iformat, int flags);
#define FBOTEX_FUZZY_W 1
#define FBOTEX_FUZZY_H 2
#define FBOTEX_FUZZY (FBOTEX_FUZZY_W | FBOTEX_FUZZY_H)
void fbotex_set_filter(struct fbotex *fbo, GLenum gl_filter);

// A 3x2 matrix, with the translation part separate.
struct gl_transform {
    float m[2][2];
    float t[2];
};

void gl_transform_ortho(struct gl_transform *t, float x0, float x1,
                        float y0, float y1);

// This treats m as an affine transformation, in other words m[2][n] gets
// added to the output.
static inline void gl_transform_vec(struct gl_transform t, float *x, float *y)
{
    float vx = *x, vy = *y;
    *x = vx * t.m[0][0] + vy * t.m[1][0] + t.t[0];
    *y = vx * t.m[0][1] + vy * t.m[1][1] + t.t[1];
}

struct mp_rect_f {
    float x0, y0, x1, y1;
};

static inline void gl_transform_rect(struct gl_transform t, struct mp_rect_f *r)
{
    gl_transform_vec(t, &r->x0, &r->y0);
    gl_transform_vec(t, &r->x1, &r->y1);
}

void gl_set_debug_logger(GL *gl, struct mp_log *log);

struct gl_shader_cache;

struct gl_shader_cache *gl_sc_create(GL *gl, struct mp_log *log,
                                     struct mpv_global *global);
void gl_sc_destroy(struct gl_shader_cache *sc);
void gl_sc_add(struct gl_shader_cache *sc, const char *text);
void gl_sc_addf(struct gl_shader_cache *sc, const char *textf, ...);
void gl_sc_hadd(struct gl_shader_cache *sc, const char *text);
const char *gl_sc_loadfile(struct gl_shader_cache *sc, const char *path);
void gl_sc_uniform_sampler(struct gl_shader_cache *sc, char *name, GLenum target,
                           int unit);
void gl_sc_uniform_f(struct gl_shader_cache *sc, char *name, GLfloat f);
void gl_sc_uniform_i(struct gl_shader_cache *sc, char *name, GLint f);
void gl_sc_uniform_vec2(struct gl_shader_cache *sc, char *name, GLfloat f[2]);
void gl_sc_uniform_vec3(struct gl_shader_cache *sc, char *name, GLfloat f[3]);
void gl_sc_uniform_mat2(struct gl_shader_cache *sc, char *name,
                        bool transpose, GLfloat *v);
void gl_sc_uniform_mat3(struct gl_shader_cache *sc, char *name,
                        bool transpose, GLfloat *v);
void gl_sc_set_vao(struct gl_shader_cache *sc, struct gl_vao *vao);
void gl_sc_gen_shader_and_reset(struct gl_shader_cache *sc);
void gl_sc_reset(struct gl_shader_cache *sc);

#endif