/**************************************************************************
 *
 * 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
 * TGSI to LLVM IR translation.
 *
 * @author Jose Fonseca <jfonseca@vmware.com>
 */

#ifndef LP_BLD_TGSI_H
#define LP_BLD_TGSI_H

#include "gallivm/lp_bld.h"
#include "pipe/p_compiler.h"
#include "pipe/p_state.h"
#include "tgsi/tgsi_scan.h"


struct tgsi_token;
struct tgsi_shader_info;
struct lp_type;
struct lp_build_context;
struct lp_build_mask_context;
struct gallivm_state;


enum lp_build_tex_modifier {
   LP_BLD_TEX_MODIFIER_NONE = 0,
   LP_BLD_TEX_MODIFIER_PROJECTED,
   LP_BLD_TEX_MODIFIER_LOD_BIAS,
   LP_BLD_TEX_MODIFIER_EXPLICIT_LOD,
   LP_BLD_TEX_MODIFIER_EXPLICIT_DERIV
};


/**
 * Describe a channel of a register.
 *
 * The value can be a:
 * - immediate value (i.e. derived from a IMM register)
 * - CONST[n].x/y/z/w
 * - IN[n].x/y/z/w
 * - undetermined (when .file == TGSI_FILE_NULL)
 *
 * This is one of the analysis results, and is used to described
 * the output color in terms of inputs.
 */
struct lp_tgsi_channel_info
{
   unsigned file:4; /* TGSI_FILE_* */
   unsigned swizzle:3; /* PIPE_SWIZZLE_x */
   union {
      uint32_t index;
      float value; /* for TGSI_FILE_IMMEDIATE */
   } u;
};


/**
 * Describe a texture sampler interpolator.
 *
 * The interpolation is described in terms of regular inputs.
 */
struct lp_tgsi_texture_info
{
   struct lp_tgsi_channel_info coord[4];
   unsigned target:8; /* TGSI_TEXTURE_* */
   unsigned unit:8;  /* Sampler unit */
   unsigned modifier:8; /* LP_BLD_TEX_MODIFIER_* */
};


struct lp_tgsi_info
{
   struct tgsi_shader_info base;

   /*
    * Whether any of the texture opcodes access a register file other than
    * TGSI_FILE_INPUT.
    *
    * We could also handle TGSI_FILE_CONST/IMMEDIATE here, but there is little
    * benefit.
    */
   unsigned indirect_textures:1;

   /*
    * Texture opcode description. Aimed at detecting and described direct
    * texture opcodes.
    */
   unsigned num_texs;
   struct lp_tgsi_texture_info tex[PIPE_MAX_SAMPLERS];

   /*
    * Output description. Aimed at detecting and describing simple blit
    * shaders.
    */
   struct lp_tgsi_channel_info output[PIPE_MAX_SHADER_OUTPUTS][4];

   /*
    * Shortcut pointers into the above (for fragment shaders).
    */
   const struct lp_tgsi_channel_info *cbuf[PIPE_MAX_COLOR_BUFS];
};

/**
 * Sampler code generation interface.
 *
 * Although texture sampling is a requirement for TGSI translation, it is
 * a very different problem with several different approaches to it. This
 * structure establishes an interface for texture sampling code generation, so
 * that we can easily use different texture sampling strategies.
 */
struct lp_build_sampler_soa
{
   void
   (*destroy)( struct lp_build_sampler_soa *sampler );

   void
   (*emit_fetch_texel)( const struct lp_build_sampler_soa *sampler,
                        struct gallivm_state *gallivm,
                        struct lp_type type,
                        unsigned unit,
                        unsigned num_coords,
                        const LLVMValueRef *coords,
                        const LLVMValueRef *ddx,
                        const LLVMValueRef *ddy,
                        LLVMValueRef lod_bias, /* optional */
                        LLVMValueRef explicit_lod, /* optional */
                        LLVMValueRef *texel);
};


struct lp_build_sampler_aos
{
   LLVMValueRef
   (*emit_fetch_texel)( struct lp_build_sampler_aos *sampler,
                        struct lp_build_context *bld,
                        unsigned target, /* TGSI_TEXTURE_* */
                        unsigned unit,
                        LLVMValueRef coords,
                        LLVMValueRef ddx,
                        LLVMValueRef ddy,
                        enum lp_build_tex_modifier modifier);
};


void
lp_build_tgsi_info(const struct tgsi_token *tokens,
                   struct lp_tgsi_info *info);


void
lp_build_tgsi_soa(struct gallivm_state *gallivm,
                  const struct tgsi_token *tokens,
                  struct lp_type type,
                  struct lp_build_mask_context *mask,
                  LLVMValueRef consts_ptr,
                  LLVMValueRef system_values_array,
                  const LLVMValueRef *pos,
                  const LLVMValueRef (*inputs)[4],
                  LLVMValueRef (*outputs)[4],
                  struct lp_build_sampler_soa *sampler,
                  const struct tgsi_shader_info *info);


void
lp_build_tgsi_aos(struct gallivm_state *gallivm,
                  const struct tgsi_token *tokens,
                  struct lp_type type,
                  const unsigned char swizzles[4],
                  LLVMValueRef consts_ptr,
                  const LLVMValueRef *inputs,
                  LLVMValueRef *outputs,
                  struct lp_build_sampler_aos *sampler,
                  const struct tgsi_shader_info *info);


LLVMValueRef
lp_build_system_values_array(struct gallivm_state *gallivm,
                             const struct tgsi_shader_info *info,
                             LLVMValueRef instance_id,
                             LLVMValueRef facing);


#endif /* LP_BLD_TGSI_H */