text: /**************************************************************************
   *
   * Copyright 2009 VMware, Inc.
   * All Rights Reserved.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sub license, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice (including the
   * next paragraph) shall be included in all copies or substantial portions
   * of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
   * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
   * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
   * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   *
   **************************************************************************/
  
  /**
   * @file
   * Texture sampling.
   *
   * @author Jose Fonseca <jfonseca@vmware.com>
   */
  
  #ifndef LP_BLD_SAMPLE_H
  #define LP_BLD_SAMPLE_H
  
  
  #include "pipe/p_format.h"
  #include "util/u_debug.h"
  #include "gallivm/lp_bld.h"
  #include "gallivm/lp_bld_type.h"
  #include "gallivm/lp_bld_swizzle.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  struct pipe_resource;
  struct pipe_sampler_view;
  struct pipe_sampler_state;
  struct util_format_description;
  struct lp_type;
  struct lp_build_context;
  
  
  /**
   * Helper struct holding all derivatives needed for sampling
   */
  struct lp_derivatives
  {
     LLVMValueRef ddx[3];
     LLVMValueRef ddy[3];
  };
  
  
  enum lp_sampler_lod_property {
     LP_SAMPLER_LOD_SCALAR,
     LP_SAMPLER_LOD_PER_ELEMENT,
     LP_SAMPLER_LOD_PER_QUAD
  };
  
  
  enum lp_sampler_lod_control {
     LP_SAMPLER_LOD_IMPLICIT,
     LP_SAMPLER_LOD_BIAS,
     LP_SAMPLER_LOD_EXPLICIT,
     LP_SAMPLER_LOD_DERIVATIVES,
  };
  
  
  enum lp_sampler_op_type {
     LP_SAMPLER_OP_TEXTURE,
     LP_SAMPLER_OP_FETCH,
     LP_SAMPLER_OP_GATHER,
     LP_SAMPLER_OP_LODQ
  };
  
  
  #define LP_SAMPLER_SHADOW             (1 << 0)
  #define LP_SAMPLER_OFFSETS            (1 << 1)
  #define LP_SAMPLER_OP_TYPE_SHIFT            2
  #define LP_SAMPLER_OP_TYPE_MASK       (3 << 2)
  #define LP_SAMPLER_LOD_CONTROL_SHIFT        4
  #define LP_SAMPLER_LOD_CONTROL_MASK   (3 << 4)
  #define LP_SAMPLER_LOD_PROPERTY_SHIFT       6
  #define LP_SAMPLER_LOD_PROPERTY_MASK  (3 << 6)
  
  struct lp_sampler_params
  {
     struct lp_type type;
     unsigned texture_index;
     unsigned sampler_index;
     unsigned sample_key;
     LLVMValueRef context_ptr;
     LLVMValueRef thread_data_ptr;
     const LLVMValueRef *coords;
     const LLVMValueRef *offsets;
     LLVMValueRef lod;
     const struct lp_derivatives *derivs;
     LLVMValueRef *texel;
  };
  
  struct lp_sampler_size_query_params
  {
     struct lp_type int_type;
     unsigned texture_unit;
     unsigned target;
     LLVMValueRef context_ptr;
     boolean is_sviewinfo;
     enum lp_sampler_lod_property lod_property;
     LLVMValueRef explicit_lod;
     LLVMValueRef *sizes_out;
  };
  /**
   * Texture static state.
   *
   * These are the bits of state from pipe_resource/pipe_sampler_view that
   * are embedded in the generated code.
   */
  struct lp_static_texture_state
  {
     /* pipe_sampler_view's state */
     enum pipe_format format;
     unsigned swizzle_r:3;     /**< PIPE_SWIZZLE_* */
     unsigned swizzle_g:3;
     unsigned swizzle_b:3;
     unsigned swizzle_a:3;
  
     /* pipe_texture's state */
     unsigned target:4;        /**< PIPE_TEXTURE_* */
     unsigned pot_width:1;     /**< is the width a power of two? */
     unsigned pot_height:1;
     unsigned pot_depth:1;
     unsigned level_zero_only:1;
  };
  
  
  /**
   * Sampler static state.
   *
   * These are the bits of state from pipe_sampler_state that
   * are embedded in the generated code.
   */
  struct lp_static_sampler_state
  {
     /* pipe_sampler_state's state */
     unsigned wrap_s:3;
     unsigned wrap_t:3;
     unsigned wrap_r:3;
     unsigned min_img_filter:2;
     unsigned min_mip_filter:2;
     unsigned mag_img_filter:2;
     unsigned compare_mode:1;
     unsigned compare_func:3;
     unsigned normalized_coords:1;
     unsigned min_max_lod_equal:1;  /**< min_lod == max_lod ? */
     unsigned lod_bias_non_zero:1;
     unsigned max_lod_pos:1;
     unsigned apply_min_lod:1;  /**< min_lod > 0 ? */
     unsigned apply_max_lod:1;  /**< max_lod < last_level ? */
     unsigned seamless_cube_map:1;
  
     /* Hacks */
     unsigned force_nearest_s:1;
     unsigned force_nearest_t:1;
  };
  
  
  /**
   * Sampler dynamic state.
   *
   * These are the bits of state from pipe_resource/pipe_sampler_view
   * as well as from sampler state that are computed at runtime.
   *
   * There are obtained through callbacks, as we don't want to tie the texture
   * sampling code generation logic to any particular texture layout or pipe
   * driver.
   */
  struct lp_sampler_dynamic_state
  {
     /* First callbacks for sampler view state */
  
     /** Obtain the base texture width (or number of elements) (returns int32) */
     LLVMValueRef
     (*width)(const struct lp_sampler_dynamic_state *state,
              struct gallivm_state *gallivm,
              LLVMValueRef context_ptr,
              unsigned texture_unit);
  
     /** Obtain the base texture height (returns int32) */
     LLVMValueRef
     (*height)(const struct lp_sampler_dynamic_state *state,
               struct gallivm_state *gallivm,
               LLVMValueRef context_ptr,
               unsigned texture_unit);
  
     /** Obtain the base texture depth (or array size) (returns int32) */
     LLVMValueRef
     (*depth)(const struct lp_sampler_dynamic_state *state,
              struct gallivm_state *gallivm,
              LLVMValueRef context_ptr,
              unsigned texture_unit);
  
     /** Obtain the first mipmap level (base level) (returns int32) */
     LLVMValueRef
     (*first_level)(const struct lp_sampler_dynamic_state *state,
                    struct gallivm_state *gallivm,
                    LLVMValueRef context_ptr,
                    unsigned texture_unit);
  
     /** Obtain the number of mipmap levels minus one (returns int32) */
     LLVMValueRef
     (*last_level)(const struct lp_sampler_dynamic_state *state,
                   struct gallivm_state *gallivm,
                   LLVMValueRef context_ptr,
                   unsigned texture_unit);
  
     /** Obtain stride in bytes between image rows/blocks (returns int32) */
     LLVMValueRef
     (*row_stride)(const struct lp_sampler_dynamic_state *state,
                   struct gallivm_state *gallivm,
                   LLVMValueRef context_ptr,
                   unsigned texture_unit);
  
     /** Obtain stride in bytes between image slices (returns int32) */
     LLVMValueRef
     (*img_stride)(const struct lp_sampler_dynamic_state *state,
                   struct gallivm_state *gallivm,
                   LLVMValueRef context_ptr,
                   unsigned texture_unit);
  
     /** Obtain pointer to base of texture */
     LLVMValueRef
     (*base_ptr)(const struct lp_sampler_dynamic_state *state,
                 struct gallivm_state *gallivm,
                 LLVMValueRef context_ptr,
                 unsigned texture_unit);
  
     /** Obtain pointer to array of mipmap offsets */
     LLVMValueRef
     (*mip_offsets)(const struct lp_sampler_dynamic_state *state,
                    struct gallivm_state *gallivm,
                    LLVMValueRef context_ptr,
                    unsigned texture_unit);
  
     /* These are callbacks for sampler state */
  
     /** Obtain texture min lod (returns float) */
     LLVMValueRef
     (*min_lod)(const struct lp_sampler_dynamic_state *state,
                struct gallivm_state *gallivm,
                LLVMValueRef context_ptr,
                unsigned sampler_unit);
  
     /** Obtain texture max lod (returns float) */
     LLVMValueRef
     (*max_lod)(const struct lp_sampler_dynamic_state *state,
                struct gallivm_state *gallivm,
                LLVMValueRef context_ptr,
                unsigned sampler_unit);
  
     /** Obtain texture lod bias (returns float) */
     LLVMValueRef
     (*lod_bias)(const struct lp_sampler_dynamic_state *state,
                 struct gallivm_state *gallivm,
                 LLVMValueRef context_ptr,
                 unsigned sampler_unit);
  
     /** Obtain texture border color (returns ptr to float[4]) */
     LLVMValueRef
     (*border_color)(const struct lp_sampler_dynamic_state *state,
                     struct gallivm_state *gallivm,
                     LLVMValueRef context_ptr,
                     unsigned sampler_unit);
  
     /** 
      * Obtain texture cache (returns ptr to lp_build_format_cache).
      *
      * It's optional: no caching will be done if it's NULL.
      */
     LLVMValueRef
     (*cache_ptr)(const struct lp_sampler_dynamic_state *state,
                  struct gallivm_state *gallivm,
                  LLVMValueRef thread_data_ptr,
                  unsigned unit);
  };
  
  
  /**
   * Keep all information for sampling code generation in a single place.
   */
  struct lp_build_sample_context
  {
     struct gallivm_state *gallivm;
  
     const struct lp_static_texture_state *static_texture_state;
     const struct lp_static_sampler_state *static_sampler_state;
  
     struct lp_sampler_dynamic_state *dynamic_state;
  
     const struct util_format_description *format_desc;
  
     /* See texture_dims() */
     unsigned dims;
  
     /** SIMD vector width */
     unsigned vector_width;
  
     /** number of mipmaps (valid are 1, length/4, length) */
     unsigned num_mips;
  
     /** number of lod values (valid are 1, length/4, length) */
     unsigned num_lods;
  
     boolean no_quad_lod;
     boolean no_brilinear;
     boolean no_rho_approx;
  
     /** regular scalar float type */
     struct lp_type float_type;
     struct lp_build_context float_bld;
  
     /** float vector type */
     struct lp_build_context float_vec_bld;
  
     /** regular scalar int type */
     struct lp_type int_type;
     struct lp_build_context int_bld;
  
     /** Incoming coordinates type and build context */
     struct lp_type coord_type;
     struct lp_build_context coord_bld;
  
     /** Signed integer coordinates */
     struct lp_type int_coord_type;
     struct lp_build_context int_coord_bld;
  
     /** Unsigned integer texture size */
     struct lp_type int_size_in_type;
     struct lp_build_context int_size_in_bld;
  
     /** Float incoming texture size */
     struct lp_type float_size_in_type;
     struct lp_build_context float_size_in_bld;
  
     /** Unsigned integer texture size (might be per quad) */
     struct lp_type int_size_type;
     struct lp_build_context int_size_bld;
  
     /** Float texture size (might be per quad) */
     struct lp_type float_size_type;
     struct lp_build_context float_size_bld;
  
     /** Output texels type and build context */
     struct lp_type texel_type;
     struct lp_build_context texel_bld;
  
     /** Float level type */
     struct lp_type levelf_type;
     struct lp_build_context levelf_bld;
  
     /** Int level type */
     struct lp_type leveli_type;
     struct lp_build_context leveli_bld;
  
     /** Float lod type */
     struct lp_type lodf_type;
     struct lp_build_context lodf_bld;
  
     /** Int lod type */
     struct lp_type lodi_type;
     struct lp_build_context lodi_bld;
  
     /* Common dynamic state values */
     LLVMValueRef row_stride_array;
     LLVMValueRef img_stride_array;
     LLVMValueRef base_ptr;
     LLVMValueRef mip_offsets;
     LLVMValueRef cache;
  
     /** Integer vector with texture width, height, depth */
     LLVMValueRef int_size;
  
     LLVMValueRef border_color_clamped;
  
     LLVMValueRef context_ptr;
  };
  
  
  
  /**
   * We only support a few wrap modes in lp_build_sample_wrap_linear_int() at
   * this time.  Return whether the given mode is supported by that function.
   */
  static inline boolean
  lp_is_simple_wrap_mode(unsigned mode)
  {
     switch (mode) {
     case PIPE_TEX_WRAP_REPEAT:
     case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
        return TRUE;
     default:
        return FALSE;
     }
  }
  
  
  static inline void
  apply_sampler_swizzle(struct lp_build_sample_context *bld,
                        LLVMValueRef *texel)
  {
     unsigned char swizzles[4];
  
     swizzles[0] = bld->static_texture_state->swizzle_r;
     swizzles[1] = bld->static_texture_state->swizzle_g;
     swizzles[2] = bld->static_texture_state->swizzle_b;
     swizzles[3] = bld->static_texture_state->swizzle_a;
  
     lp_build_swizzle_soa_inplace(&bld->texel_bld, texel, swizzles);
  }
  
  /*
   * not really dimension as such, this indicates the amount of
   * "normal" texture coords subject to minification, wrapping etc.
   */
  static inline unsigned
  texture_dims(enum pipe_texture_target tex)
  {
     switch (tex) {
     case PIPE_TEXTURE_1D:
     case PIPE_TEXTURE_1D_ARRAY:
     case PIPE_BUFFER:
        return 1;
     case PIPE_TEXTURE_2D:
     case PIPE_TEXTURE_2D_ARRAY:
     case PIPE_TEXTURE_RECT:
     case PIPE_TEXTURE_CUBE:
     case PIPE_TEXTURE_CUBE_ARRAY:
        return 2;
     case PIPE_TEXTURE_3D:
        return 3;
     default:
        assert(0 && "bad texture target in texture_dims()");
        return 2;
     }
  }
  
  static inline boolean
  has_layer_coord(enum pipe_texture_target tex)
  {
     switch (tex) {
     case PIPE_TEXTURE_1D_ARRAY:
     case PIPE_TEXTURE_2D_ARRAY:
     /* cube is not layered but 3rd coord (after cube mapping) behaves the same */
     case PIPE_TEXTURE_CUBE:
     case PIPE_TEXTURE_CUBE_ARRAY:
        return TRUE;
     default:
        return FALSE;
     }
  }
  
  
  boolean
  lp_sampler_wrap_mode_uses_border_color(unsigned mode,
                                         unsigned min_img_filter,
                                         unsigned mag_img_filter);
  
  /**
   * Derive the sampler static state.
   */
  void
  lp_sampler_static_sampler_state(struct lp_static_sampler_state *state,
                                  const struct pipe_sampler_state *sampler);
  
  
  void
  lp_sampler_static_texture_state(struct lp_static_texture_state *state,
                                  const struct pipe_sampler_view *view);
  
  
  void
  lp_build_lod_selector(struct lp_build_sample_context *bld,
                        boolean is_lodq,
                        unsigned texture_index,
                        unsigned sampler_index,
                        LLVMValueRef s,
                        LLVMValueRef t,
                        LLVMValueRef r,
                        LLVMValueRef cube_rho,
                        const struct lp_derivatives *derivs,
                        LLVMValueRef lod_bias, /* optional */
                        LLVMValueRef explicit_lod, /* optional */
                        unsigned mip_filter,
                        LLVMValueRef *out_lod,
                        LLVMValueRef *out_lod_ipart,
                        LLVMValueRef *out_lod_fpart,
                        LLVMValueRef *out_lod_positive);
  
  void
  lp_build_nearest_mip_level(struct lp_build_sample_context *bld,
                             unsigned texture_unit,
                             LLVMValueRef lod,
                             LLVMValueRef *level_out,
                             LLVMValueRef *out_of_bounds);
  
  void
  lp_build_linear_mip_levels(struct lp_build_sample_context *bld,
                             unsigned texture_unit,
                             LLVMValueRef lod_ipart,
                             LLVMValueRef *lod_fpart_inout,
                             LLVMValueRef *level0_out,
                             LLVMValueRef *level1_out);
  
  LLVMValueRef
  lp_build_get_mipmap_level(struct lp_build_sample_context *bld,
                            LLVMValueRef level);
  
  
  LLVMValueRef
  lp_build_get_mip_offsets(struct lp_build_sample_context *bld,
                           LLVMValueRef level);
  
  
  void
  lp_build_mipmap_level_sizes(struct lp_build_sample_context *bld,
                              LLVMValueRef ilevel,
                              LLVMValueRef *out_size_vec,
                              LLVMValueRef *row_stride_vec,
                              LLVMValueRef *img_stride_vec);
  
  
  void
  lp_build_extract_image_sizes(struct lp_build_sample_context *bld,
                               struct lp_build_context *size_bld,
                               struct lp_type coord_type,
                               LLVMValueRef size,
                               LLVMValueRef *out_width,
                               LLVMValueRef *out_height,
                               LLVMValueRef *out_depth);
  
  
  void
  lp_build_unnormalized_coords(struct lp_build_sample_context *bld,
                               LLVMValueRef flt_size,
                               LLVMValueRef *s,
                               LLVMValueRef *t,
                               LLVMValueRef *r);
  
  
  void
  lp_build_cube_lookup(struct lp_build_sample_context *bld,
                       LLVMValueRef *coords,
                       const struct lp_derivatives *derivs_in, /* optional */
                       LLVMValueRef *rho,
                       struct lp_derivatives *derivs_out, /* optional */
                       boolean need_derivs);
  
  
  void
  lp_build_cube_new_coords(struct lp_build_context *ivec_bld,
                           LLVMValueRef face,
                           LLVMValueRef x0,
                           LLVMValueRef x1,
                           LLVMValueRef y0,
                           LLVMValueRef y1,
                           LLVMValueRef max_coord,
                           LLVMValueRef new_faces[4],
                           LLVMValueRef new_xcoords[4][2],
                           LLVMValueRef new_ycoords[4][2]);
  
  
  void
  lp_build_sample_partial_offset(struct lp_build_context *bld,
                                 unsigned block_length,
                                 LLVMValueRef coord,
                                 LLVMValueRef stride,
                                 LLVMValueRef *out_offset,
                                 LLVMValueRef *out_i);
  
  
  void
  lp_build_sample_offset(struct lp_build_context *bld,
                         const struct util_format_description *format_desc,
                         LLVMValueRef x,
                         LLVMValueRef y,
                         LLVMValueRef z,
                         LLVMValueRef y_stride,
                         LLVMValueRef z_stride,
                         LLVMValueRef *out_offset,
                         LLVMValueRef *out_i,
                         LLVMValueRef *out_j);
  
  
  void
  lp_build_sample_soa(const struct lp_static_texture_state *static_texture_state,
                      const struct lp_static_sampler_state *static_sampler_state,
                      struct lp_sampler_dynamic_state *dynamic_texture_state,
                      struct gallivm_state *gallivm,
                      const struct lp_sampler_params *params);
  
  
  void
  lp_build_coord_repeat_npot_linear(struct lp_build_sample_context *bld,
                                    LLVMValueRef coord_f,
                                    LLVMValueRef length_i,
                                    LLVMValueRef length_f,
                                    LLVMValueRef *coord0_i,
                                    LLVMValueRef *weight_f);
  
  
  void
  lp_build_size_query_soa(struct gallivm_state *gallivm,
                          const struct lp_static_texture_state *static_state,
                          struct lp_sampler_dynamic_state *dynamic_state,
                          const struct lp_sampler_size_query_params *params);
  
  void
  lp_build_sample_nop(struct gallivm_state *gallivm, 
                      struct lp_type type,
                      const LLVMValueRef *coords,
                      LLVMValueRef texel_out[4]);
  
  
  LLVMValueRef
  lp_build_minify(struct lp_build_context *bld,
                  LLVMValueRef base_size,
                  LLVMValueRef level,
                  boolean lod_scalar);
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* LP_BLD_SAMPLE_H */
  