From a65bdf5f47689b52ec97181ec870b089872b508e Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Tue, 1 Sep 2015 16:29:17 -0600 Subject: [PATCH] tgsi: add new tgsi_two_side.c utility code This could be used by any driver where the device doesn't directly support two-sided lighting. This code modifies a fragment shader to accecpt back-face colors and choose between the front/back colors depending on the triangle's front-face sign. --- src/gallium/auxiliary/Makefile.sources | 2 + src/gallium/auxiliary/tgsi/tgsi_two_side.c | 228 +++++++++++++++++++++ src/gallium/auxiliary/tgsi/tgsi_two_side.h | 34 +++ 3 files changed, 264 insertions(+) create mode 100644 src/gallium/auxiliary/tgsi/tgsi_two_side.c create mode 100644 src/gallium/auxiliary/tgsi/tgsi_two_side.h diff --git a/src/gallium/auxiliary/Makefile.sources b/src/gallium/auxiliary/Makefile.sources index 3616d885b47..d5986b45e06 100644 --- a/src/gallium/auxiliary/Makefile.sources +++ b/src/gallium/auxiliary/Makefile.sources @@ -154,6 +154,8 @@ C_SOURCES := \ tgsi/tgsi_text.h \ tgsi/tgsi_transform.c \ tgsi/tgsi_transform.h \ + tgsi/tgsi_two_side.c \ + tgsi/tgsi_two_side.h \ tgsi/tgsi_ureg.c \ tgsi/tgsi_ureg.h \ tgsi/tgsi_util.c \ diff --git a/src/gallium/auxiliary/tgsi/tgsi_two_side.c b/src/gallium/auxiliary/tgsi/tgsi_two_side.c new file mode 100644 index 00000000000..2406e2876f3 --- /dev/null +++ b/src/gallium/auxiliary/tgsi/tgsi_two_side.c @@ -0,0 +1,228 @@ +/* + * Copyright 2013 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 THE AUTHORS 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. + */ + + +/** + * This utility transforms fragment shaders to facilitate two-sided lighting. + * + * Basically, if the FS has any color inputs (TGSI_SEMANTIC_COLOR) we'll: + * 1. create corresponding back-color inputs (TGSI_SEMANTIC_BCOLOR) + * 2. use the FACE register to choose between front/back colors and put the + * selected color in new temp regs. + * 3. replace reads of the original color inputs with the new temp regs. + * + * Then, the driver just needs to link the VS front/back output colors to + * the FS front/back input colors. + */ + +#include "util/u_debug.h" +#include "util/u_math.h" +#include "tgsi_info.h" +#include "tgsi_two_side.h" +#include "tgsi_transform.h" + + +#define INVALID_INDEX 9999 + + +struct two_side_transform_context +{ + struct tgsi_transform_context base; + uint num_temps; + uint num_inputs; + uint face_input; /**< index of the FACE input */ + uint front_color_input[2]; /**< INPUT regs */ + uint front_color_interp[2];/**< TGSI_INTERPOLATE_x */ + uint back_color_input[2]; /**< INPUT regs */ + uint new_colors[2]; /**< TEMP regs */ +}; + + +static inline struct two_side_transform_context * +two_side_transform_context(struct tgsi_transform_context *ctx) +{ + return (struct two_side_transform_context *) ctx; +} + + +static void +xform_decl(struct tgsi_transform_context *ctx, + struct tgsi_full_declaration *decl) +{ + struct two_side_transform_context *ts = two_side_transform_context(ctx); + + if (decl->Declaration.File == TGSI_FILE_INPUT) { + if (decl->Semantic.Name == TGSI_SEMANTIC_COLOR) { + /* found a front color */ + assert(decl->Semantic.Index < 2); + ts->front_color_input[decl->Semantic.Index] = decl->Range.First; + ts->front_color_interp[decl->Semantic.Index] = decl->Interp.Interpolate; + } + else if (decl->Semantic.Name == TGSI_SEMANTIC_FACE) { + ts->face_input = decl->Range.First; + } + ts->num_inputs = MAX2(ts->num_inputs, decl->Range.Last + 1); + } + else if (decl->Declaration.File == TGSI_FILE_TEMPORARY) { + ts->num_temps = MAX2(ts->num_temps, decl->Range.Last + 1); + } + + ctx->emit_declaration(ctx, decl); +} + + +static void +emit_prolog(struct tgsi_transform_context *ctx) +{ + struct two_side_transform_context *ts = two_side_transform_context(ctx); + struct tgsi_full_declaration decl; + struct tgsi_full_instruction inst; + uint num_colors = 0; + uint i; + + /* Declare 0, 1 or 2 new BCOLOR inputs */ + for (i = 0; i < 2; i++) { + if (ts->front_color_input[i] != INVALID_INDEX) { + decl = tgsi_default_full_declaration(); + decl.Declaration.File = TGSI_FILE_INPUT; + decl.Declaration.Interpolate = 1; + decl.Declaration.Semantic = 1; + decl.Semantic.Name = TGSI_SEMANTIC_BCOLOR; + decl.Semantic.Index = i; + decl.Range.First = decl.Range.Last = ts->num_inputs++; + decl.Interp.Interpolate = ts->front_color_interp[i]; + ctx->emit_declaration(ctx, &decl); + ts->back_color_input[i] = decl.Range.First; + num_colors++; + } + } + + if (num_colors > 0) { + /* Declare 1 or 2 temp registers */ + decl = tgsi_default_full_declaration(); + decl.Declaration.File = TGSI_FILE_TEMPORARY; + decl.Range.First = ts->num_temps; + decl.Range.Last = ts->num_temps + num_colors - 1; + ctx->emit_declaration(ctx, &decl); + ts->new_colors[0] = ts->num_temps; + ts->new_colors[1] = ts->num_temps + 1; + + if (ts->face_input == INVALID_INDEX) { + /* declare FACE INPUT register */ + decl = tgsi_default_full_declaration(); + decl.Declaration.File = TGSI_FILE_INPUT; + decl.Declaration.Semantic = 1; + decl.Semantic.Name = TGSI_SEMANTIC_FACE; + decl.Semantic.Index = 0; + decl.Range.First = decl.Range.Last = ts->num_inputs++; + ctx->emit_declaration(ctx, &decl); + ts->face_input = decl.Range.First; + } + + /* CMP temp[c0], face, bcolor[c0], fcolor[c0] + * temp[c0] = face < 0.0 ? bcolor[c0] : fcolor[c0] + */ + for (i = 0; i < 2; i++) { + if (ts->front_color_input[i] != INVALID_INDEX) { + inst = tgsi_default_full_instruction(); + inst.Instruction.Opcode = TGSI_OPCODE_CMP; + inst.Instruction.NumDstRegs = 1; + inst.Dst[0].Register.File = TGSI_FILE_TEMPORARY; + inst.Dst[0].Register.Index = ts->new_colors[i]; + inst.Instruction.NumSrcRegs = 3; + inst.Src[0].Register.File = TGSI_FILE_INPUT; + inst.Src[0].Register.Index = ts->face_input; + inst.Src[1].Register.File = TGSI_FILE_INPUT; + inst.Src[1].Register.Index = ts->back_color_input[i]; + inst.Src[2].Register.File = TGSI_FILE_INPUT; + inst.Src[2].Register.Index = ts->front_color_input[i]; + + ctx->emit_instruction(ctx, &inst); + } + } + } +} + + +static void +xform_inst(struct tgsi_transform_context *ctx, + struct tgsi_full_instruction *inst) +{ + struct two_side_transform_context *ts = two_side_transform_context(ctx); + const struct tgsi_opcode_info *info = + tgsi_get_opcode_info(inst->Instruction.Opcode); + uint i, j; + + /* Look for src regs which reference the input color and replace + * them with the temp color. + */ + for (i = 0; i < info->num_src; i++) { + if (inst->Src[i].Register.File == TGSI_FILE_INPUT) { + for (j = 0; j < 2; j++) { + if (inst->Src[i].Register.Index == ts->front_color_input[j]) { + /* replace color input with temp reg */ + inst->Src[i].Register.File = TGSI_FILE_TEMPORARY; + inst->Src[i].Register.Index = ts->new_colors[j]; + break; + } + } + } + } + + ctx->emit_instruction(ctx, inst); +} + + +struct tgsi_token * +tgsi_add_two_side(const struct tgsi_token *tokens_in) +{ + struct two_side_transform_context transform; + const uint num_new_tokens = 100; /* should be enough */ + const uint new_len = tgsi_num_tokens(tokens_in) + num_new_tokens; + struct tgsi_token *new_tokens; + + /* setup transformation context */ + memset(&transform, 0, sizeof(transform)); + transform.base.transform_declaration = xform_decl; + transform.base.transform_instruction = xform_inst; + transform.base.prolog = emit_prolog; + transform.face_input = INVALID_INDEX; + transform.front_color_input[0] = INVALID_INDEX; + transform.front_color_input[1] = INVALID_INDEX; + transform.front_color_interp[0] = TGSI_INTERPOLATE_COLOR; + transform.front_color_interp[1] = TGSI_INTERPOLATE_COLOR; + transform.back_color_input[0] = INVALID_INDEX; + transform.back_color_input[1] = INVALID_INDEX; + + /* allocate new tokens buffer */ + new_tokens = tgsi_alloc_tokens(new_len); + if (!new_tokens) + return NULL; + + /* transform the shader */ + tgsi_transform_shader(tokens_in, new_tokens, new_len, &transform.base); + + return new_tokens; +} diff --git a/src/gallium/auxiliary/tgsi/tgsi_two_side.h b/src/gallium/auxiliary/tgsi/tgsi_two_side.h new file mode 100644 index 00000000000..bac239e41af --- /dev/null +++ b/src/gallium/auxiliary/tgsi/tgsi_two_side.h @@ -0,0 +1,34 @@ +/* + * Copyright 2013 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 THE AUTHORS 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. + */ + +#ifndef TGSI_TWO_SIDE_H +#define TGSI_TWO_SIDE_H + +struct tgsi_token; + +struct tgsi_token * +tgsi_add_two_side(const struct tgsi_token *tokens_in); + +#endif /* TGSI_TWO_SIDE_H */ -- 2.30.2