/*
 * This program 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.
 *
 * This program 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 this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2012 Blender Foundation.
 * All rights reserved.
 */

/** \file
 * \ingroup gpu
 */

#ifndef __GPU_MATRIX_H__
#define __GPU_MATRIX_H__

#include "BLI_sys_types.h"

#ifdef __cplusplus
extern "C" {
#endif

struct GPUShaderInterface;

void GPU_matrix_reset(void); /* to Identity transform & empty stack */

/* ModelView Matrix (2D or 3D) */

void GPU_matrix_push(void); /* TODO: PushCopy vs PushIdentity? */
void GPU_matrix_pop(void);

void GPU_matrix_identity_set(void);

void GPU_matrix_scale_1f(float factor);

/* 3D ModelView Matrix */

void GPU_matrix_set(const float m[4][4]);
void GPU_matrix_mul(const float m[4][4]);

void GPU_matrix_translate_3f(float x, float y, float z);
void GPU_matrix_translate_3fv(const float vec[3]);
void GPU_matrix_scale_3f(float x, float y, float z);
void GPU_matrix_scale_3fv(const float vec[3]);

/* Axis of rotation should be a unit vector. */
void GPU_matrix_rotate_3f(float deg, float x, float y, float z);
/* Axis of rotation should be a unit vector. */
void GPU_matrix_rotate_3fv(float deg, const float axis[3]);

void GPU_matrix_rotate_axis(float deg, char axis); /* TODO: enum for axis? */

void GPU_matrix_look_at(float eyeX,
                        float eyeY,
                        float eyeZ,
                        float centerX,
                        float centerY,
                        float centerZ,
                        float upX,
                        float upY,
                        float upZ);
/* TODO: variant that takes eye[3], center[3], up[3] */

/* 2D ModelView Matrix */

void GPU_matrix_translate_2f(float x, float y);
void GPU_matrix_translate_2fv(const float vec[2]);
void GPU_matrix_scale_2f(float x, float y);
void GPU_matrix_scale_2fv(const float vec[2]);
void GPU_matrix_rotate_2d(float deg);

/* Projection Matrix (2D or 3D) */

void GPU_matrix_push_projection(void);
void GPU_matrix_pop_projection(void);

/* 3D Projection Matrix */

void GPU_matrix_identity_projection_set(void);
void GPU_matrix_projection_set(const float m[4][4]);

void GPU_matrix_ortho_set(float left, float right, float bottom, float top, float near, float far);
void GPU_matrix_ortho_set_z(float near, float far);

void GPU_matrix_frustum_set(
    float left, float right, float bottom, float top, float near, float far);
void GPU_matrix_perspective_set(float fovy, float aspect, float near, float far);

/* 3D Projection between Window and World Space */

struct GPUMatrixUnproject_Precalc {
  float model_inverted[4][4];
  float view[4];
  bool is_persp;
  /** Result of 'projmat_dimensions'. */
  struct {
    float xmin, xmax;
    float ymin, ymax;
    float zmin, zmax;
  } dims;
};

bool GPU_matrix_unproject_precalc(struct GPUMatrixUnproject_Precalc *unproj_precalc,
                                  const float model[4][4],
                                  const float proj[4][4],
                                  const int view[4]);

void GPU_matrix_project(const float world[3],
                        const float model[4][4],
                        const float proj[4][4],
                        const int view[4],
                        float r_win[3]);

bool GPU_matrix_unproject(const float win[3],
                          const float model[4][4],
                          const float proj[4][4],
                          const int view[4],
                          float r_world[3]);

void GPU_matrix_unproject_with_precalc(const struct GPUMatrixUnproject_Precalc *unproj_precalc,
                                       const float win[3],
                                       float r_world[3]);

/* 2D Projection Matrix */

void GPU_matrix_ortho_2d_set(float left, float right, float bottom, float top);

/* functions to get matrix values */
const float (*GPU_matrix_model_view_get(float m[4][4]))[4];
const float (*GPU_matrix_projection_get(float m[4][4]))[4];
const float (*GPU_matrix_model_view_projection_get(float m[4][4]))[4];

const float (*GPU_matrix_normal_get(float m[3][3]))[3];
const float (*GPU_matrix_normal_inverse_get(float m[3][3]))[3];

/* set uniform values for currently bound shader */
void GPU_matrix_bind(const struct GPUShaderInterface *);
bool GPU_matrix_dirty_get(void); /* since last bind */

/* Python API needs to be able to inspect the stack so errors raise exceptions
 * instead of crashing. */
#ifdef USE_GPU_PY_MATRIX_API
int GPU_matrix_stack_level_get_model_view(void);
int GPU_matrix_stack_level_get_projection(void);
/* static assert ensures this doesn't change! */
#  define GPU_PY_MATRIX_STACK_LEN 31
#endif /* USE_GPU_PY_MATRIX_API */

#ifdef __cplusplus
}
#endif

#ifndef SUPPRESS_GENERIC_MATRIX_API

#  if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
#    define _GPU_MAT3_CONST_CAST(x) \
      (_Generic((x), \
  void *:       (const float (*)[3])(x), \
  float *:      (const float (*)[3])(x), \
  float [9]:    (const float (*)[3])(x), \
  float (*)[4]: (const float (*)[3])(x), \
  float [4][4]: (const float (*)[3])(x), \
  const void *:       (const float (*)[3])(x), \
  const float *:      (const float (*)[3])(x), \
  const float [9]:    (const float (*)[3])(x), \
  const float (*)[3]: (const float (*)[3])(x), \
  const float [3][3]: (const float (*)[3])(x)) \
)
#    define _GPU_MAT3_CAST(x) \
      (_Generic((x), \
  void *:       (float (*)[3])(x), \
  float *:      (float (*)[3])(x), \
  float [9]:    (float (*)[3])(x), \
  float (*)[3]: (float (*)[3])(x), \
  float [3][3]: (float (*)[3])(x)) \
)
#    define _GPU_MAT4_CONST_CAST(x) \
      (_Generic((x), \
  void *:       (const float (*)[4])(x), \
  float *:      (const float (*)[4])(x), \
  float [16]:   (const float (*)[4])(x), \
  float (*)[4]: (const float (*)[4])(x), \
  float [4][4]: (const float (*)[4])(x), \
  const void *:       (const float (*)[4])(x), \
  const float *:      (const float (*)[4])(x), \
  const float [16]:   (const float (*)[4])(x), \
  const float (*)[4]: (const float (*)[4])(x), \
  const float [4][4]: (const float (*)[4])(x)) \
)
#    define _GPU_MAT4_CAST(x) \
      (_Generic((x), \
  void *:       (float (*)[4])(x), \
  float *:      (float (*)[4])(x), \
  float [16]:   (float (*)[4])(x), \
  float (*)[4]: (float (*)[4])(x), \
  float [4][4]: (float (*)[4])(x)) \
)
#  else
#    define _GPU_MAT3_CONST_CAST(x) (const float(*)[3])(x)
#    define _GPU_MAT3_CAST(x) (float(*)[3])(x)
#    define _GPU_MAT4_CONST_CAST(x) (const float(*)[4])(x)
#    define _GPU_MAT4_CAST(x) (float(*)[4])(x)
#  endif /* C11 */

/* make matrix inputs generic, to avoid warnings */
#  define GPU_matrix_mul(x) GPU_matrix_mul(_GPU_MAT4_CONST_CAST(x))
#  define GPU_matrix_set(x) GPU_matrix_set(_GPU_MAT4_CONST_CAST(x))
#  define GPU_matrix_projection_set(x) GPU_matrix_projection_set(_GPU_MAT4_CONST_CAST(x))
#  define GPU_matrix_model_view_get(x) GPU_matrix_model_view_get(_GPU_MAT4_CAST(x))
#  define GPU_matrix_projection_get(x) GPU_matrix_projection_get(_GPU_MAT4_CAST(x))
#  define GPU_matrix_model_view_projection_get(x) \
    GPU_matrix_model_view_projection_get(_GPU_MAT4_CAST(x))
#  define GPU_matrix_normal_get(x) GPU_matrix_normal_get(_GPU_MAT3_CAST(x))
#  define GPU_matrix_normal_inverse_get(x) GPU_matrix_normal_inverse_get(_GPU_MAT3_CAST(x))
#endif /* SUPPRESS_GENERIC_MATRIX_API */

/* Not part of the GPU_matrix API,
 * however we need to check these limits in code that calls into these API's. */
#define GPU_MATRIX_ORTHO_CLIP_NEAR_DEFAULT (-100)
#define GPU_MATRIX_ORTHO_CLIP_FAR_DEFAULT (100)

#endif /* __GPU_MATRIX_H__ */
