/*
 * Cogl
 *
 * An object oriented GL/GLES Abstraction/Utility Layer
 *
 * Copyright (C) 2008,2009,2010,2011 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, see
 * <http://www.gnu.org/licenses/>.
 *
 *
 *
 * Authors:
 *   Robert Bragg <robert@linux.intel.com>
 */

#ifndef __COGL_PIPELINE_LAYER_PRIVATE_H
#define __COGL_PIPELINE_LAYER_PRIVATE_H

#include "cogl-pipeline.h"
#include "cogl-node-private.h"
#include "cogl-texture.h"
#include "cogl-matrix.h"
#include "cogl-pipeline-layer-state.h"
#include "cogl-internal.h"
#include "cogl-pipeline-snippet-private.h"

#include <glib.h>

/* This isn't defined in the GLES headers */
#ifndef GL_CLAMP_TO_BORDER
#define GL_CLAMP_TO_BORDER 0x812d
#endif
#ifndef GL_MIRRORED_REPEAT
#define GL_MIRRORED_REPEAT 0x8370
#endif

typedef struct _CoglPipelineLayer     CoglPipelineLayer;
#define COGL_PIPELINE_LAYER(OBJECT) ((CoglPipelineLayer *)OBJECT)

/* GL_ALWAYS is just used here as a value that is known not to clash
 * with any valid GL wrap modes.
 *
 * XXX: keep the values in sync with the CoglPipelineWrapMode enum
 * so no conversion is actually needed.
 */
typedef enum _CoglPipelineWrapModeInternal
{
  COGL_PIPELINE_WRAP_MODE_INTERNAL_REPEAT = GL_REPEAT,
  COGL_PIPELINE_WRAP_MODE_INTERNAL_MIRRORED_REPEAT = GL_MIRRORED_REPEAT,
  COGL_PIPELINE_WRAP_MODE_INTERNAL_CLAMP_TO_EDGE = GL_CLAMP_TO_EDGE,
  COGL_PIPELINE_WRAP_MODE_INTERNAL_CLAMP_TO_BORDER = GL_CLAMP_TO_BORDER,
  COGL_PIPELINE_WRAP_MODE_INTERNAL_AUTOMATIC = GL_ALWAYS
} CoglPipelineWrapModeInternal;

/* XXX: should I rename these as
 * COGL_PIPELINE_LAYER_STATE_INDEX_XYZ... ?
 */
typedef enum
{
  /* sparse state */
  COGL_PIPELINE_LAYER_STATE_UNIT_INDEX,
  COGL_PIPELINE_LAYER_STATE_TEXTURE_TARGET_INDEX,
  COGL_PIPELINE_LAYER_STATE_TEXTURE_DATA_INDEX,
  COGL_PIPELINE_LAYER_STATE_FILTERS_INDEX,
  COGL_PIPELINE_LAYER_STATE_WRAP_MODES_INDEX,
  COGL_PIPELINE_LAYER_STATE_COMBINE_INDEX,
  COGL_PIPELINE_LAYER_STATE_COMBINE_CONSTANT_INDEX,
  COGL_PIPELINE_LAYER_STATE_USER_MATRIX_INDEX,
  COGL_PIPELINE_LAYER_STATE_POINT_SPRITE_COORDS_INDEX,
  COGL_PIPELINE_LAYER_STATE_VERTEX_SNIPPETS_INDEX,
  COGL_PIPELINE_LAYER_STATE_FRAGMENT_SNIPPETS_INDEX,

  /* note: layers don't currently have any non-sparse state */

  COGL_PIPELINE_LAYER_STATE_SPARSE_COUNT,
  COGL_PIPELINE_LAYER_STATE_COUNT = COGL_PIPELINE_LAYER_STATE_SPARSE_COUNT
} CoglPipelineLayerStateIndex;

/* XXX: If you add or remove state groups here you may need to update
 * some of the state masks following this enum too!
 *
 * FIXME: perhaps it would be better to rename this enum to
 * CoglPipelineLayerStateGroup to better convey the fact that a single
 * enum here can map to multiple properties.
 */
typedef enum
{
  COGL_PIPELINE_LAYER_STATE_UNIT =
    1L<<COGL_PIPELINE_LAYER_STATE_UNIT_INDEX,
  COGL_PIPELINE_LAYER_STATE_TEXTURE_TARGET =
    1L<<COGL_PIPELINE_LAYER_STATE_TEXTURE_TARGET_INDEX,
  COGL_PIPELINE_LAYER_STATE_TEXTURE_DATA =
    1L<<COGL_PIPELINE_LAYER_STATE_TEXTURE_DATA_INDEX,
  COGL_PIPELINE_LAYER_STATE_FILTERS =
    1L<<COGL_PIPELINE_LAYER_STATE_FILTERS_INDEX,
  COGL_PIPELINE_LAYER_STATE_WRAP_MODES =
    1L<<COGL_PIPELINE_LAYER_STATE_WRAP_MODES_INDEX,

  COGL_PIPELINE_LAYER_STATE_COMBINE =
    1L<<COGL_PIPELINE_LAYER_STATE_COMBINE_INDEX,
  COGL_PIPELINE_LAYER_STATE_COMBINE_CONSTANT =
    1L<<COGL_PIPELINE_LAYER_STATE_COMBINE_CONSTANT_INDEX,
  COGL_PIPELINE_LAYER_STATE_USER_MATRIX =
    1L<<COGL_PIPELINE_LAYER_STATE_USER_MATRIX_INDEX,

  COGL_PIPELINE_LAYER_STATE_POINT_SPRITE_COORDS =
    1L<<COGL_PIPELINE_LAYER_STATE_POINT_SPRITE_COORDS_INDEX,

  COGL_PIPELINE_LAYER_STATE_VERTEX_SNIPPETS =
    1L<<COGL_PIPELINE_LAYER_STATE_VERTEX_SNIPPETS_INDEX,
  COGL_PIPELINE_LAYER_STATE_FRAGMENT_SNIPPETS =
    1L<<COGL_PIPELINE_LAYER_STATE_FRAGMENT_SNIPPETS_INDEX,

  /* COGL_PIPELINE_LAYER_STATE_TEXTURE_INTERN   = 1L<<8, */

} CoglPipelineLayerState;

/*
 * Various special masks that tag state-groups in different ways...
 */

#define COGL_PIPELINE_LAYER_STATE_ALL \
  ((1L<<COGL_PIPELINE_LAYER_STATE_COUNT) - 1)

#define COGL_PIPELINE_LAYER_STATE_ALL_SPARSE \
  COGL_PIPELINE_LAYER_STATE_ALL

#define COGL_PIPELINE_LAYER_STATE_NEEDS_BIG_STATE \
  (COGL_PIPELINE_LAYER_STATE_COMBINE | \
   COGL_PIPELINE_LAYER_STATE_COMBINE_CONSTANT | \
   COGL_PIPELINE_LAYER_STATE_USER_MATRIX | \
   COGL_PIPELINE_LAYER_STATE_POINT_SPRITE_COORDS | \
   COGL_PIPELINE_LAYER_STATE_VERTEX_SNIPPETS | \
   COGL_PIPELINE_LAYER_STATE_FRAGMENT_SNIPPETS)

#define COGL_PIPELINE_LAYER_STATE_MULTI_PROPERTY \
  (COGL_PIPELINE_LAYER_STATE_FILTERS | \
   COGL_PIPELINE_LAYER_STATE_WRAP_MODES | \
   COGL_PIPELINE_LAYER_STATE_COMBINE | \
   COGL_PIPELINE_LAYER_STATE_VERTEX_SNIPPETS | \
   COGL_PIPELINE_LAYER_STATE_FRAGMENT_SNIPPETS)

#define COGL_PIPELINE_LAYER_STATE_AFFECTS_VERTEX_CODEGEN \
  COGL_PIPELINE_LAYER_STATE_VERTEX_SNIPPETS

typedef enum
{
  /* These are the same values as GL */
  COGL_PIPELINE_COMBINE_FUNC_ADD         = 0x0104,
  COGL_PIPELINE_COMBINE_FUNC_ADD_SIGNED  = 0x8574,
  COGL_PIPELINE_COMBINE_FUNC_SUBTRACT    = 0x84E7,
  COGL_PIPELINE_COMBINE_FUNC_INTERPOLATE = 0x8575,
  COGL_PIPELINE_COMBINE_FUNC_REPLACE     = 0x1E01,
  COGL_PIPELINE_COMBINE_FUNC_MODULATE    = 0x2100,
  COGL_PIPELINE_COMBINE_FUNC_DOT3_RGB    = 0x86AE,
  COGL_PIPELINE_COMBINE_FUNC_DOT3_RGBA   = 0x86AF
} CoglPipelineCombineFunc;

typedef enum
{
  /* These are the same values as GL */
  COGL_PIPELINE_COMBINE_SOURCE_TEXTURE       = 0x1702,
  COGL_PIPELINE_COMBINE_SOURCE_CONSTANT      = 0x8576,
  COGL_PIPELINE_COMBINE_SOURCE_PRIMARY_COLOR = 0x8577,
  COGL_PIPELINE_COMBINE_SOURCE_PREVIOUS      = 0x8578,
  COGL_PIPELINE_COMBINE_SOURCE_TEXTURE0      = 0x84C0
} CoglPipelineCombineSource;

typedef enum
{
  /* These are the same values as GL */
  COGL_PIPELINE_COMBINE_OP_SRC_COLOR           = 0x0300,
  COGL_PIPELINE_COMBINE_OP_ONE_MINUS_SRC_COLOR = 0x0301,
  COGL_PIPELINE_COMBINE_OP_SRC_ALPHA           = 0x0302,
  COGL_PIPELINE_COMBINE_OP_ONE_MINUS_SRC_ALPHA = 0x0303
} CoglPipelineCombineOp;

typedef struct
{
  /* The texture combine state determines how the color of individual
   * texture fragments are calculated. */
  CoglPipelineCombineFunc texture_combine_rgb_func;
  CoglPipelineCombineSource texture_combine_rgb_src[3];
  CoglPipelineCombineOp texture_combine_rgb_op[3];

  CoglPipelineCombineFunc texture_combine_alpha_func;
  CoglPipelineCombineSource texture_combine_alpha_src[3];
  CoglPipelineCombineOp texture_combine_alpha_op[3];

  float texture_combine_constant[4];

  /* The texture matrix dscribes how to transform texture coordinates */
  CoglMatrix matrix;

  gboolean point_sprite_coords;

  CoglPipelineSnippetList vertex_snippets;
  CoglPipelineSnippetList fragment_snippets;
} CoglPipelineLayerBigState;

struct _CoglPipelineLayer
{
  /* XXX: Please think twice about adding members that *have* be
   * initialized during a _cogl_pipeline_layer_copy. We are aiming
   * to have copies be as cheap as possible and copies may be
   * done by the primitives APIs which means they may happen
   * in performance critical code paths.
   *
   * XXX: If you are extending the state we track please consider if
   * the state is expected to vary frequently across many pipelines or
   * if the state can be shared among many derived pipelines instead.
   * This will determine if the state should be added directly to this
   * structure which will increase the memory overhead for *all*
   * layers or if instead it can go under ->big_state.
   */

  /* Layers represent their state in a tree structure where some of
   * the state relating to a given pipeline or layer may actually be
   * owned by one if is ancestors in the tree. We have a common data
   * type to track the tree heirachy so we can share code... */
  CoglNode _parent;

  /* Some layers have a pipeline owner, which is to say that the layer
   * is referenced in that pipelines->layer_differences list.  A layer
   * doesn't always have an owner and may simply be an ancestor for
   * other layers that keeps track of some shared state. */
  CoglPipeline      *owner;

  /* The lowest index is blended first then others on top */
  int	             index;

  /* A mask of which state groups are different in this layer
   * in comparison to its parent. */
  unsigned long             differences;

  /* Common differences
   *
   * As a basic way to reduce memory usage we divide the layer
   * state into two groups; the minimal state modified in 90% of
   * all layers and the rest, so that the second group can
   * be allocated dynamically when required.
   */

  /* Each layer is directly associated with a single texture unit */
  int                        unit_index;

  /* The texture for this layer, or NULL for an empty
   * layer */
  CoglTexture               *texture;
  GLenum                     target;

  CoglPipelineFilter         mag_filter;
  CoglPipelineFilter         min_filter;

  CoglPipelineWrapModeInternal wrap_mode_s;
  CoglPipelineWrapModeInternal wrap_mode_t;
  CoglPipelineWrapModeInternal wrap_mode_p;

  /* Infrequent differences aren't currently tracked in
   * a separate, dynamically allocated structure as they are
   * for pipelines... */
  CoglPipelineLayerBigState *big_state;

  /* bitfields */

  /* Determines if layer->big_state is valid */
  unsigned int          has_big_state:1;

};

typedef gboolean
(*CoglPipelineLayerStateComparitor) (CoglPipelineLayer *authority0,
                                     CoglPipelineLayer *authority1);



void
_cogl_pipeline_init_default_layers (void);

static inline CoglPipelineLayer *
_cogl_pipeline_layer_get_parent (CoglPipelineLayer *layer)
{
  CoglNode *parent_node = COGL_NODE (layer)->parent;
  return COGL_PIPELINE_LAYER (parent_node);
}

CoglPipelineLayer *
_cogl_pipeline_layer_copy (CoglPipelineLayer *layer);

void
_cogl_pipeline_layer_resolve_authorities (CoglPipelineLayer *layer,
                                          unsigned long differences,
                                          CoglPipelineLayer **authorities);

gboolean
_cogl_pipeline_layer_equal (CoglPipelineLayer *layer0,
                            CoglPipelineLayer *layer1,
                            unsigned long differences_mask,
                            CoglPipelineEvalFlags flags);

CoglPipelineLayer *
_cogl_pipeline_layer_pre_change_notify (CoglPipeline *required_owner,
                                        CoglPipelineLayer *layer,
                                        CoglPipelineLayerState change);

void
_cogl_pipeline_layer_prune_redundant_ancestry (CoglPipelineLayer *layer);

gboolean
_cogl_pipeline_layer_has_alpha (CoglPipelineLayer *layer);

gboolean
_cogl_pipeline_layer_has_user_matrix (CoglPipeline *pipeline,
                                      int layer_index);

/*
 * Calls the pre_paint method on the layer texture if there is
 * one. This will determine whether mipmaps are needed based on the
 * filter settings.
 */
void
_cogl_pipeline_layer_pre_paint (CoglPipelineLayer *layerr);

void
_cogl_pipeline_layer_get_wrap_modes (CoglPipelineLayer *layer,
                                     CoglPipelineWrapModeInternal *wrap_mode_s,
                                     CoglPipelineWrapModeInternal *wrap_mode_t,
                                     CoglPipelineWrapModeInternal *wrap_mode_r);

void
_cogl_pipeline_layer_get_filters (CoglPipelineLayer *layer,
                                  CoglPipelineFilter *min_filter,
                                  CoglPipelineFilter *mag_filter);

void
_cogl_pipeline_get_layer_filters (CoglPipeline *pipeline,
                                  int layer_index,
                                  CoglPipelineFilter *min_filter,
                                  CoglPipelineFilter *mag_filter);

typedef enum {
  COGL_PIPELINE_LAYER_TYPE_TEXTURE
} CoglPipelineLayerType;

CoglPipelineLayerType
_cogl_pipeline_layer_get_type (CoglPipelineLayer *layer);

CoglTexture *
_cogl_pipeline_layer_get_texture (CoglPipelineLayer *layer);

CoglTexture *
_cogl_pipeline_layer_get_texture_real (CoglPipelineLayer *layer);

CoglPipelineFilter
_cogl_pipeline_layer_get_min_filter (CoglPipelineLayer *layer);

CoglPipelineFilter
_cogl_pipeline_layer_get_mag_filter (CoglPipelineLayer *layer);

CoglPipelineWrapMode
_cogl_pipeline_layer_get_wrap_mode_s (CoglPipelineLayer *layer);

CoglPipelineWrapMode
_cogl_pipeline_layer_get_wrap_mode_t (CoglPipelineLayer *layer);

CoglPipelineWrapMode
_cogl_pipeline_layer_get_wrap_mode_p (CoglPipelineLayer *layer);

unsigned long
_cogl_pipeline_layer_compare_differences (CoglPipelineLayer *layer0,
                                          CoglPipelineLayer *layer1);

CoglPipelineLayer *
_cogl_pipeline_layer_get_authority (CoglPipelineLayer *layer,
                                    unsigned long difference);

CoglTexture *
_cogl_pipeline_layer_get_texture (CoglPipelineLayer *layer);

int
_cogl_pipeline_layer_get_unit_index (CoglPipelineLayer *layer);

gboolean
_cogl_pipeline_layer_needs_combine_separate
                                       (CoglPipelineLayer *combine_authority);

#endif /* __COGL_PIPELINE_LAYER_PRIVATE_H */