/*
 * Cogl
 *
 * An object oriented GL/GLES Abstraction/Utility Layer
 *
 * Copyright (C) 2009 Intel Corporation.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Authors:
 *   Havoc Pennington <hp@pobox.com> for litl
 *   Robert Bragg     <robert@linux.intel.com>
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "cogl.h"
#include "cogl-context.h"
#include "cogl-internal.h"
#include "cogl-current-matrix.h"
#include "cogl-matrix-stack.h"

#ifdef HAVE_COGL_GLES2
#include "cogl-gles2-wrapper.h"

#define glFrustum(L,R,B,T,N,F) \
            cogl_wrap_glFrustumf((GLfloat)L, (GLfloat)R, (GLfloat)B, \
                                 (GLfloat)T, (GLfloat)N, (GLfloat)F)
#elif defined (HAVE_COGL_GLES)

#define glFrustum(L,R,B,T,N,F) \
            glFrustumf((GLfloat)L, (GLfloat)R, (GLfloat)B, \
                       (GLfloat)T, (GLfloat)N, (GLfloat)F)

#define glOrtho glOrthof

#endif

#include <string.h>
#include <math.h>

static void
_cogl_get_client_stack (CoglContext      *ctx,
                        CoglMatrixMode    mode,
                        CoglMatrixStack **current_stack_p)
{
  switch (mode)
    {
    case COGL_MATRIX_MODELVIEW:
      *current_stack_p = ctx->modelview_stack;
      break;
    case COGL_MATRIX_PROJECTION:
      *current_stack_p = ctx->projection_stack;
      break;
    case COGL_MATRIX_TEXTURE:
      g_critical ("The current-matrix API doesn't support the texture matrix "
                  "you must deal with the CoglMatrixStack directly");
      *current_stack_p  = NULL;
      break;
    }
  g_assert (*current_stack_p);
}

#define _COGL_GET_CONTEXT_AND_STACK(contextvar, stackvar, rval) \
  CoglMatrixStack *stackvar;                                    \
  _COGL_GET_CONTEXT (contextvar, rval);                         \
  _cogl_get_client_stack (contextvar, ctx->matrix_mode, &stackvar)

void
_cogl_set_current_matrix (CoglMatrixMode mode)
{
  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  if (mode == ctx->matrix_mode)
    return;
  ctx->matrix_mode = mode;
}

void
_cogl_current_matrix_push (void)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_push (current_stack);
}

void
_cogl_current_matrix_pop (void)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_pop (current_stack);
}

void
_cogl_current_matrix_identity (void)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_load_identity (current_stack);
}

void
_cogl_current_matrix_load (const CoglMatrix *matrix)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_set (current_stack, matrix);
}

void
_cogl_current_matrix_multiply (const CoglMatrix *matrix)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_multiply (current_stack, matrix);
}

void
_cogl_current_matrix_rotate (float angle,
                             float x,
                             float y,
                             float z)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_rotate (current_stack, angle, x, y, z);
}

void
_cogl_current_matrix_scale (float x,
                            float y,
                            float z)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_scale (current_stack, x, y, z);
}

void
_cogl_current_matrix_translate (float x,
                                float y,
                                float z)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_translate (current_stack, x, y, z);
}

void
_cogl_current_matrix_frustum (float left,
                              float right,
                              float bottom,
                              float top,
                              float near_val,
                              float far_val)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_frustum (current_stack,
                              left, right,
                              bottom, top,
                              near_val,
                              far_val);
}

void
_cogl_current_matrix_perspective (float fov_y,
                                  float aspect,
                                  float z_near,
                                  float z_far)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_perspective (current_stack,
                                  fov_y, aspect, z_near, z_far);
}

void
_cogl_current_matrix_ortho (float left,
                            float right,
                            float bottom,
                            float top,
                            float near_val,
                            float far_val)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_ortho (current_stack,
                            left, right,
                            bottom, top,
                            near_val,
                            far_val);
}

void
_cogl_get_matrix (CoglMatrixMode mode,
                  CoglMatrix    *matrix)
{
  CoglMatrixStack *current_stack;
  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  _cogl_get_client_stack (ctx, mode, &current_stack);

  _cogl_matrix_stack_get (current_stack, matrix);
}

void
_cogl_set_matrix (const CoglMatrix *matrix)
{
  _cogl_current_matrix_load (matrix);
}

void
_cogl_current_matrix_state_init (void)
{
  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  ctx->matrix_mode = COGL_MATRIX_MODELVIEW;
  ctx->projection_stack = _cogl_matrix_stack_new ();
  ctx->modelview_stack = _cogl_matrix_stack_new ();
}

void
_cogl_current_matrix_state_destroy (void)
{
  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  _cogl_matrix_stack_destroy (ctx->projection_stack);
  _cogl_matrix_stack_destroy (ctx->modelview_stack);
}

void
_cogl_current_matrix_state_flush (void)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_flush_to_gl (current_stack, ctx->matrix_mode);
}

void
_cogl_current_matrix_state_dirty (void)
{
  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
  _cogl_matrix_stack_dirty (current_stack);
}

void
cogl_push_matrix (void)
{
  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
  _cogl_current_matrix_push ();
}

void
cogl_pop_matrix (void)
{
  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
  _cogl_current_matrix_pop ();
}

void
cogl_scale (float x, float y, float z)
{
  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
  _cogl_current_matrix_scale (x, y, z);
}

void
cogl_translate (float x, float y, float z)
{
  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
  _cogl_current_matrix_translate (x, y, z);
}

void
cogl_rotate (float angle, float x, float y, float z)
{
  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
  _cogl_current_matrix_rotate (angle, x, y, z);
}

void
cogl_perspective (float fov_y,
		  float aspect,
		  float z_near,
		  float z_far)
{
  float ymax = z_near * tanf (fov_y * G_PI / 360.0);

  cogl_frustum (-ymax * aspect,  /* left */
                ymax * aspect,   /* right */
                -ymax,           /* bottom */
                ymax,            /* top */
                z_near,
                z_far);
}

void
cogl_frustum (float        left,
	      float        right,
	      float        bottom,
	      float        top,
	      float        z_near,
	      float        z_far)
{
  float c, d;

  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
  _cogl_current_matrix_identity ();

  _cogl_current_matrix_frustum (left,
                                right,
                                bottom,
                                top,
                                z_near,
                                z_far);

  /* Calculate and store the inverse of the matrix */
  memset (ctx->inverse_projection, 0, sizeof (float) * 16);

  c = - (z_far + z_near) /  (z_far - z_near);
  d = - (2 * (z_far * z_near)) /  (z_far - z_near);

#define M(row,col)  ctx->inverse_projection[col*4+row]
  M(0,0) =  (right - left) /  (2 * z_near);
  M(0,3) =  (right + left) /  (2 * z_near);
  M(1,1) =  (top - bottom) /  (2 * z_near);
  M(1,3) =  (top + bottom) /  (2 * z_near);
  M(2,3) = -1.0;
  M(3,2) = 1.0 / d;
  M(3,3) = c / d;
#undef M

  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
}

void
cogl_ortho (float left,
	    float right,
	    float bottom,
	    float top,
	    float z_near,
	    float z_far)
{
  CoglMatrix ortho;
  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  cogl_matrix_init_identity (&ortho);
  cogl_matrix_ortho (&ortho, left, right, bottom, top, z_near, z_far);
  _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
  _cogl_current_matrix_load (&ortho);

  /* Calculate and store the inverse of the matrix */
  memset (ctx->inverse_projection, 0, sizeof (float) * 16);

#define M(row,col)  ctx->inverse_projection[col*4+row]
  M(0,0) =  1.0 / ortho.xx;
  M(0,3) =  -ortho.xw;
  M(1,1) =  1.0 / ortho.yy;
  M(1,3) =  -ortho.yw;
  M(2,2) =  1.0 / ortho.zz;
  M(2,3) =  -ortho.zw;
  M(3,3) =  1.0;
#undef M
}

void
cogl_get_modelview_matrix (CoglMatrix *matrix)
{
  _cogl_get_matrix (COGL_MATRIX_MODELVIEW,
                    matrix);
}

void
cogl_set_modelview_matrix (CoglMatrix *matrix)
{
  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
  _cogl_current_matrix_load (matrix);
}

void
cogl_get_projection_matrix (CoglMatrix *matrix)
{
  _cogl_get_matrix (COGL_MATRIX_PROJECTION,
                    matrix);
}

void
cogl_set_projection_matrix (CoglMatrix *matrix)
{
  _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
  _cogl_current_matrix_load (matrix);
}

void
_cogl_flush_matrix_stacks (void)
{
  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  _cogl_matrix_stack_flush_to_gl (ctx->projection_stack, COGL_MATRIX_PROJECTION);
  _cogl_matrix_stack_flush_to_gl (ctx->modelview_stack, COGL_MATRIX_MODELVIEW);
}