/*
 * 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-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-pipeline-snippet-private.h"
#include "cogl-sampler-cache-private.h"

#include <glib.h>

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

/* 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_TYPE_INDEX,
  COGL_PIPELINE_LAYER_STATE_TEXTURE_DATA_INDEX,
  COGL_PIPELINE_LAYER_STATE_SAMPLER_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_TYPE =
    1L<<COGL_PIPELINE_LAYER_STATE_TEXTURE_TYPE_INDEX,
  COGL_PIPELINE_LAYER_STATE_TEXTURE_DATA =
    1L<<COGL_PIPELINE_LAYER_STATE_TEXTURE_DATA_INDEX,
  COGL_PIPELINE_LAYER_STATE_SAMPLER =
    1L<<COGL_PIPELINE_LAYER_STATE_SAMPLER_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_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
{
  /* Note that these numbers are deliberately not the same as the GL
     numbers so that we can reserve all numbers > TEXTURE0 to store
     very large layer numbers */
  COGL_PIPELINE_COMBINE_SOURCE_TEXTURE,
  COGL_PIPELINE_COMBINE_SOURCE_CONSTANT,
  COGL_PIPELINE_COMBINE_SOURCE_PRIMARY_COLOR,
  COGL_PIPELINE_COMBINE_SOURCE_PREVIOUS,
  COGL_PIPELINE_COMBINE_SOURCE_TEXTURE0
} 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;

  CoglBool 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;
  /* The type of the texture. This is always set even if the texture
     is NULL and it will be used to determine what type of texture
     lookups to use in any shaders generated by the pipeline
     backends. */
  CoglTextureType            texture_type;

  const CoglSamplerCacheEntry *sampler_cache_entry;

  /* 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 CoglBool
(*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);

CoglBool
_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);

CoglBool
_cogl_pipeline_layer_has_alpha (CoglPipelineLayer *layer);

CoglBool
_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,
                                     CoglSamplerCacheWrapMode *wrap_mode_s,
                                     CoglSamplerCacheWrapMode *wrap_mode_t,
                                     CoglSamplerCacheWrapMode *wrap_mode_r);

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

const CoglSamplerCacheEntry *
_cogl_pipeline_layer_get_sampler_state (CoglPipelineLayer *layer);

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);

CoglTextureType
_cogl_pipeline_layer_get_texture_type (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);

CoglBool
_cogl_pipeline_layer_needs_combine_separate
                                       (CoglPipelineLayer *combine_authority);

#endif /* __COGL_PIPELINE_LAYER_PRIVATE_H */