text: /**************************************************************************
   *
   * Copyright (C) 2015 Advanced Micro Devices, Inc.
   * Copyright 2007 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.
   *
   **************************************************************************/
  
  #include "st_cb_drawpixels.h"
  #include "tgsi/tgsi_transform.h"
  #include "tgsi/tgsi_scan.h"
  
  struct tgsi_drawpix_transform {
     struct tgsi_transform_context base;
     struct tgsi_shader_info info;
     bool use_texcoord;
     bool scale_and_bias;
     bool pixel_maps;
     bool first_instruction_emitted;
     unsigned scale_const;
     unsigned bias_const;
     unsigned color_temp;
     unsigned drawpix_sampler;
     unsigned pixelmap_sampler;
     unsigned texcoord_const;
     unsigned tex_target;
  };
  
  static inline struct tgsi_drawpix_transform *
  tgsi_drawpix_transform(struct tgsi_transform_context *tctx)
  {
     return (struct tgsi_drawpix_transform *)tctx;
  }
  
  static void
  set_src(struct tgsi_full_instruction *inst, unsigned i, unsigned file, unsigned index,
          unsigned x, unsigned y, unsigned z, unsigned w)
  {
     inst->Src[i].Register.File  = file;
     inst->Src[i].Register.Index = index;
     inst->Src[i].Register.SwizzleX = x;
     inst->Src[i].Register.SwizzleY = y;
     inst->Src[i].Register.SwizzleZ = z;
     inst->Src[i].Register.SwizzleW = w;
  }
  
  #define SET_SRC(inst, i, file, index, x, y, z, w) \
     set_src(inst, i, file, index, TGSI_SWIZZLE_##x, TGSI_SWIZZLE_##y, \
             TGSI_SWIZZLE_##z, TGSI_SWIZZLE_##w)
  
  static void
  transform_instr(struct tgsi_transform_context *tctx,
  		struct tgsi_full_instruction *current_inst)
  {
     struct tgsi_drawpix_transform *ctx = tgsi_drawpix_transform(tctx);
     const unsigned tgsi_tex_target = ctx->tex_target == PIPE_TEXTURE_2D
        ? TGSI_TEXTURE_2D : TGSI_TEXTURE_RECT;
     unsigned i, sem_texcoord = ctx->use_texcoord ? TGSI_SEMANTIC_TEXCOORD :
                                                    TGSI_SEMANTIC_GENERIC;
     int texcoord_index = -1;
  
     if (ctx->first_instruction_emitted)
        goto transform_inst;
  
     ctx->first_instruction_emitted = true;
  
     /* Add scale and bias constants. */
     if (ctx->scale_and_bias) {
        if (ctx->info.const_file_max[0] < (int)ctx->scale_const) {
           tgsi_transform_const_decl(tctx, ctx->scale_const, ctx->scale_const);
        }
  
        if (ctx->info.const_file_max[0] < (int)ctx->bias_const) {
           tgsi_transform_const_decl(tctx, ctx->bias_const, ctx->bias_const);
        }
     }
  
     if (ctx->info.const_file_max[0] < (int)ctx->texcoord_const) {
        tgsi_transform_const_decl(tctx, ctx->texcoord_const, ctx->texcoord_const);
     }
  
     /* Add a new temp. */
     ctx->color_temp = ctx->info.file_max[TGSI_FILE_TEMPORARY] + 1;
     tgsi_transform_temp_decl(tctx, ctx->color_temp);
  
     /* Add TEXCOORD[texcoord_slot] if it's missing. */
     for (i = 0; i < ctx->info.num_inputs; i++) {
        if (ctx->info.input_semantic_name[i] == sem_texcoord &&
            ctx->info.input_semantic_index[i] == 0) {
           texcoord_index = i;
           break;
        }
     }
  
     if (texcoord_index == -1) {
        texcoord_index = ctx->info.num_inputs;
        tgsi_transform_input_decl(tctx, texcoord_index, sem_texcoord, 0,
                                  TGSI_INTERPOLATE_PERSPECTIVE);
     }
  
     /* Declare the drawpix sampler if it's missing. */
     if (!(ctx->info.samplers_declared & (1 << ctx->drawpix_sampler))) {
        tgsi_transform_sampler_decl(tctx, ctx->drawpix_sampler);
  
        /* emit sampler view declaration */
        tgsi_transform_sampler_view_decl(tctx, ctx->drawpix_sampler,
                                         tgsi_tex_target, TGSI_RETURN_TYPE_FLOAT);
     }
  
     /* Declare the pixel map sampler if it's missing. */
     if (ctx->pixel_maps &&
         !(ctx->info.samplers_declared & (1 << ctx->pixelmap_sampler))) {
        tgsi_transform_sampler_decl(tctx, ctx->pixelmap_sampler);
  
        /* emit sampler view declaration */
        tgsi_transform_sampler_view_decl(tctx, ctx->pixelmap_sampler,
                                         TGSI_TEXTURE_2D, TGSI_RETURN_TYPE_FLOAT);
     }
  
     /* Get initial pixel color from the texture.
      * TEX temp, fragment.texcoord[0], texture[0], 2D;
      */
     tgsi_transform_tex_inst(tctx, TGSI_FILE_TEMPORARY, ctx->color_temp,
                             TGSI_FILE_INPUT, texcoord_index,
                             tgsi_tex_target, ctx->drawpix_sampler);
  
     /* Apply the scale and bias. */
     if (ctx->scale_and_bias) {
        /* MAD temp, temp, scale, bias; */
        tgsi_transform_op3_inst(tctx, TGSI_OPCODE_MAD,
                                TGSI_FILE_TEMPORARY, ctx->color_temp,
                                TGSI_WRITEMASK_XYZW,
                                TGSI_FILE_TEMPORARY, ctx->color_temp,
                                TGSI_FILE_CONSTANT, ctx->scale_const,
                                TGSI_FILE_CONSTANT, ctx->bias_const);
     }
  
     if (ctx->pixel_maps) {
        /* do four pixel map look-ups with two TEX instructions: */
        struct tgsi_full_instruction inst;
  
        /* TEX temp.xy, temp.xyyy, texture[1], 2D; */
        inst = tgsi_default_full_instruction();
        inst.Instruction.Opcode = TGSI_OPCODE_TEX;
        inst.Instruction.Texture = 1;
        inst.Texture.Texture = TGSI_TEXTURE_2D;
  
        inst.Instruction.NumDstRegs = 1;
        inst.Dst[0].Register.File  = TGSI_FILE_TEMPORARY;
        inst.Dst[0].Register.Index = ctx->color_temp;
        inst.Dst[0].Register.WriteMask = TGSI_WRITEMASK_XY;
  
        inst.Instruction.NumSrcRegs = 2;
        SET_SRC(&inst, 0, TGSI_FILE_TEMPORARY, ctx->color_temp, X, Y, Y, Y);
        inst.Src[1].Register.File  = TGSI_FILE_SAMPLER;
        inst.Src[1].Register.Index = ctx->pixelmap_sampler;
  
        tctx->emit_instruction(tctx, &inst);
  
        /* TEX temp.zw, temp.zwww, texture[1], 2D; */
        inst.Dst[0].Register.WriteMask = TGSI_WRITEMASK_ZW;
        SET_SRC(&inst, 0, TGSI_FILE_TEMPORARY, ctx->color_temp, Z, W, W, W);
        tctx->emit_instruction(tctx, &inst);
     }
  
     /* Now, "color_temp" should be used in place of IN:COLOR0,
      * and CONST[texcoord_slot] should be used in place of IN:TEXCOORD0.
      */
  
  transform_inst:
  
     for (i = 0; i < current_inst->Instruction.NumSrcRegs; i++) {
        struct tgsi_full_src_register *src = &current_inst->Src[i];
        unsigned reg = src->Register.Index;
  
        if (src->Register.File != TGSI_FILE_INPUT || src->Register.Indirect)
           continue;
  
        if (ctx->info.input_semantic_name[reg] == TGSI_SEMANTIC_COLOR &&
            ctx->info.input_semantic_index[reg] == 0) {
           src->Register.File = TGSI_FILE_TEMPORARY;
           src->Register.Index = ctx->color_temp;
        } else if (ctx->info.input_semantic_name[reg] == sem_texcoord &&
                   ctx->info.input_semantic_index[reg] == 0) {
           src->Register.File = TGSI_FILE_CONSTANT;
           src->Register.Index = ctx->texcoord_const;
        }
     }
  
     tctx->emit_instruction(tctx, current_inst);
  }
  
  const struct tgsi_token *
  st_get_drawpix_shader(const struct tgsi_token *tokens, bool use_texcoord,
                        bool scale_and_bias, unsigned scale_const,
                        unsigned bias_const, bool pixel_maps,
                        unsigned drawpix_sampler, unsigned pixelmap_sampler,
                        unsigned texcoord_const, unsigned tex_target)
  {
     struct tgsi_drawpix_transform ctx;
     struct tgsi_token *newtoks;
     int newlen;
  
     assert(tex_target == PIPE_TEXTURE_2D ||
            tex_target == PIPE_TEXTURE_RECT);
  
     memset(&ctx, 0, sizeof(ctx));
     ctx.base.transform_instruction = transform_instr;
     ctx.use_texcoord = use_texcoord;
     ctx.scale_and_bias = scale_and_bias;
     ctx.scale_const = scale_const;
     ctx.bias_const = bias_const;
     ctx.pixel_maps = pixel_maps;
     ctx.drawpix_sampler = drawpix_sampler;
     ctx.pixelmap_sampler = pixelmap_sampler;
     ctx.texcoord_const = texcoord_const;
     ctx.tex_target = tex_target;
     tgsi_scan_shader(tokens, &ctx.info);
  
     newlen = tgsi_num_tokens(tokens) + 60;
     newtoks = tgsi_alloc_tokens(newlen);
     if (!newtoks)
        return NULL;
  
     tgsi_transform_shader(tokens, newtoks, newlen, &ctx.base);
     return newtoks;
  }
  