src/mesa/shader/programopt.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.2
   4  *
   5  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /**
  26  * \file  programopt.c
  27  * Vertex/Fragment program optimizations and transformations for program
  28  * options, etc.
  29  *
  30  * \author Brian Paul
  31  */
  32
  33
  34 #include "glheader.h"
  35 #include "context.h"
  36 #include "imports.h"
  37 #include "mtypes.h"
  38 #include "program.h"
  39 #include "programopt.h"
  40 #include "program_instruction.h"
  41
  42
  43 /**
  44  * This function inserts instructions for coordinate modelview * projection
  45  * into a vertex program.
  46  * May be used to implement the position_invariant option.
  47  */
  48 void
  49 _mesa_insert_mvp_code(GLcontext *ctx, struct gl_vertex_program *vprog)
  50 {
  51    struct prog_instruction *newInst;
  52    const GLuint origLen = vprog->Base.NumInstructions;
  53    const GLuint newLen = origLen + 4;
  54    GLuint i;
  55
  56    /*
  57     * Setup state references for the modelview/projection matrix.
  58     * XXX we should check if these state vars are already declared.
  59     */
  60    static const GLint mvpState[4][5] = {
  61       { STATE_MATRIX, STATE_MVP, 0, 0, 0 },  /* state.matrix.mvp.row[0] */
  62       { STATE_MATRIX, STATE_MVP, 0, 1, 1 },  /* state.matrix.mvp.row[1] */
  63       { STATE_MATRIX, STATE_MVP, 0, 2, 2 },  /* state.matrix.mvp.row[2] */
  64       { STATE_MATRIX, STATE_MVP, 0, 3, 3 },  /* state.matrix.mvp.row[3] */
  65    };
  66    GLint mvpRef[4];
  67
  68    for (i = 0; i < 4; i++) {
  69       mvpRef[i] = _mesa_add_state_reference(vprog->Base.Parameters,
  70                                             mvpState[i]);
  71    }
  72
  73    /* Alloc storage for new instructions */
  74    newInst = _mesa_alloc_instructions(newLen);
  75    if (!newInst) {
  76       _mesa_error(ctx, GL_OUT_OF_MEMORY,
  77                   "glProgramString(inserting position_invariant code)");
  78       return;
  79    }
  80
  81    /*
  82     * Generated instructions:
  83     * newInst[0] = DP4 result.position.x, mvp.row[0], vertex.position;
  84     * newInst[1] = DP4 result.position.y, mvp.row[1], vertex.position;
  85     * newInst[2] = DP4 result.position.z, mvp.row[2], vertex.position;
  86     * newInst[3] = DP4 result.position.w, mvp.row[3], vertex.position;
  87     */
  88    _mesa_init_instructions(newInst, 4);
  89    for (i = 0; i < 4; i++) {
  90       newInst[i].Opcode = OPCODE_DP4;
  91       newInst[i].DstReg.File = PROGRAM_OUTPUT;
  92       newInst[i].DstReg.Index = VERT_RESULT_HPOS;
  93       newInst[i].DstReg.WriteMask = (WRITEMASK_X << i);
  94       newInst[i].SrcReg[0].File = PROGRAM_STATE_VAR;
  95       newInst[i].SrcReg[0].Index = mvpRef[i];
  96       newInst[i].SrcReg[0].Swizzle = SWIZZLE_NOOP;
  97       newInst[i].SrcReg[1].File = PROGRAM_INPUT;
  98       newInst[i].SrcReg[1].Index = VERT_ATTRIB_POS;
  99       newInst[i].SrcReg[1].Swizzle = SWIZZLE_NOOP;
 100    }
 101
 102    /* Append original instructions after new instructions */
 103    _mesa_memcpy(newInst + 4, vprog->Base.Instructions,
 104                 origLen * sizeof(struct prog_instruction));
 105
 106    /* free old instructions */
 107    _mesa_free(vprog->Base.Instructions);
 108
 109    /* install new instructions */
 110    vprog->Base.Instructions = newInst;
 111    vprog->Base.NumInstructions = newLen;
 112    vprog->Base.InputsRead |= VERT_BIT_POS;
 113    vprog->Base.OutputsWritten |= (1 << VERT_RESULT_HPOS);
 114 }
 115
 116
 117
 118 /**
 119  * Append extra instructions onto the given fragment program to implement
 120  * the fog mode specified by fprog->FogOption.
 121  * The fragment.fogcoord input is used to compute the fog blend factor.
 122  *
 123  * XXX with a little work, this function could be adapted to add fog code
 124  * to vertex programs too.
 125  */
 126 void
 127 _mesa_append_fog_code(GLcontext *ctx, struct gl_fragment_program *fprog)
 128 {
 129    static const GLint fogParamsState[] = { STATE_FOG_PARAMS, 0, 0, 0, 0 };
 130    static const GLint fogColorState[] = { STATE_FOG_COLOR, 0, 0, 0, 0 };
 131    struct prog_instruction *newInst, *inst;
 132    const GLuint origLen = fprog->Base.NumInstructions;
 133    const GLuint newLen = origLen + 6;
 134    GLuint i;
 135    GLint fogParamsRef, fogColorRef; /* state references */
 136    GLuint colorTemp, fogFactorTemp; /* temporary registerss */
 137    GLfloat fogVals[4];
 138    GLuint fogConsts;                /* constant values for EXP, EXP2 mode */
 139
 140    if (fprog->FogOption == GL_NONE) {
 141       _mesa_problem(ctx, "_mesa_append_fog_code() called for fragment program"
 142                     " with FogOption == GL_NONE");
 143       return;
 144    }
 145
 146    /* Alloc storage for new instructions */
 147    newInst = _mesa_alloc_instructions(newLen);
 148    if (!newInst) {
 149       _mesa_error(ctx, GL_OUT_OF_MEMORY,
 150                   "glProgramString(inserting fog_option code)");
 151       return;
 152    }
 153
 154    /* Copy orig instructions into new instruction buffer */
 155    _mesa_memcpy(newInst, fprog->Base.Instructions,
 156                 origLen * sizeof(struct prog_instruction));
 157
 158    /* PARAM fogParamsRef = state.fog.params; */
 159    fogParamsRef
 160       = _mesa_add_state_reference(fprog->Base.Parameters, fogParamsState);
 161    /* PARAM fogColorRef = state.fog.color; */
 162    fogColorRef
 163       = _mesa_add_state_reference(fprog->Base.Parameters, fogColorState);
 164
 165    /* TEMP colorTemp; */
 166    colorTemp = fprog->Base.NumTemporaries++;
 167    /* TEMP fogFactorTemp; */
 168    fogFactorTemp = fprog->Base.NumTemporaries++;
 169
 170    /* PARAM fogVals = { 1/ln(2), 1/sqrt(ln(2), 0, 0 }; */
 171    fogVals[0] = 1.0 / log(2.0);
 172    fogVals[1] = 1.0 / SQRTF(log(2.0));
 173    fogVals[2] = 0.0;
 174    fogVals[3] = 0.0;
 175    fogConsts = _mesa_add_unnamed_constant(fprog->Base.Parameters, fogVals);
 176
 177    /* Scan program to find where result.color is written */
 178    inst = newInst;
 179    for (i = 0; i < fprog->Base.NumInstructions; i++) {
 180       if (inst->Opcode == OPCODE_END)
 181          break;
 182       if (inst->DstReg.File == PROGRAM_OUTPUT &&
 183           inst->DstReg.Index == FRAG_RESULT_COLR) {
 184          /* change the instruction to write to colorTemp w/ clamping */
 185          inst->DstReg.File = PROGRAM_TEMPORARY;
 186          inst->DstReg.Index = colorTemp;
 187          inst->SaturateMode = SATURATE_ZERO_ONE;
 188          /* don't break (may be several writes to result.color) */
 189       }
 190       inst++;
 191    }
 192    assert(inst->Opcode == OPCODE_END); /* we'll overwrite this inst */
 193
 194    _mesa_init_instructions(inst, 6);
 195
 196    /* emit instructions to compute fog blending factor */
 197    if (fprog->FogOption == GL_LINEAR) {
 198       /* SUB fogFactorTemp.x, fogParamsRef.z, fragment.fogcoord.x; */
 199       inst->Opcode = OPCODE_SUB;
 200       inst->DstReg.File = PROGRAM_TEMPORARY;
 201       inst->DstReg.Index = fogFactorTemp;
 202       inst->DstReg.WriteMask = WRITEMASK_X;
 203       inst->SrcReg[0].File = PROGRAM_STATE_VAR;
 204       inst->SrcReg[0].Index = fogParamsRef;
 205       inst->SrcReg[0].Swizzle = SWIZZLE_Z;
 206       inst->SrcReg[1].File = PROGRAM_INPUT;
 207       inst->SrcReg[1].Index = FRAG_ATTRIB_FOGC;
 208       inst++;
 209       /* MUL fogFactorTemp.x, fogFactorTemp, fogParamsRef.w; */
 210       inst->Opcode = OPCODE_MUL;
 211       inst->DstReg.File = PROGRAM_TEMPORARY;
 212       inst->DstReg.Index = fogFactorTemp;
 213       inst->DstReg.WriteMask = WRITEMASK_X;
 214       inst->SrcReg[0].File = PROGRAM_TEMPORARY;
 215       inst->SrcReg[0].Index = fogFactorTemp;
 216       inst->SrcReg[1].File = PROGRAM_STATE_VAR;
 217       inst->SrcReg[1].Index = fogParamsRef;
 218       inst->SrcReg[1].Swizzle = SWIZZLE_W;
 219       inst++;
 220    }
 221    else {
 222       ASSERT(fprog->FogOption == GL_EXP || fprog->FogOption == GL_EXP2);
 223       /* MUL fogFactorTemp.x, fogParamsRef.x, fragment.fogcoord; */
 224       inst->Opcode = OPCODE_MUL;
 225       inst->DstReg.File = PROGRAM_TEMPORARY;
 226       inst->DstReg.Index = fogFactorTemp;
 227       inst->DstReg.WriteMask = WRITEMASK_X;
 228       inst->SrcReg[0].File = PROGRAM_STATE_VAR;
 229       inst->SrcReg[0].Index = fogParamsRef;
 230       inst->SrcReg[0].Swizzle = SWIZZLE_X; /* X=density */
 231       inst->SrcReg[1].File = PROGRAM_INPUT;
 232       inst->SrcReg[1].Index = FRAG_ATTRIB_FOGC;
 233       inst->SrcReg[1].Swizzle = SWIZZLE_X;
 234       inst++;
 235       if (fprog->FogOption == GL_EXP2) {
 236          /* MUL fogFactorTemp.x, fogFactorTemp.x, fogFactorTemp.x; */
 237          inst->Opcode = OPCODE_MUL;
 238          inst->DstReg.File = PROGRAM_TEMPORARY;
 239          inst->DstReg.Index = fogFactorTemp;
 240          inst->DstReg.WriteMask = WRITEMASK_X;
 241          inst->SrcReg[0].File = PROGRAM_TEMPORARY;
 242          inst->SrcReg[0].Index = fogFactorTemp;
 243          inst->SrcReg[1].File = PROGRAM_TEMPORARY;
 244          inst->SrcReg[1].Index = fogFactorTemp;
 245          inst++;
 246       }
 247       /* EXP:  MUL fogFactorTemp.x, fogFactorTemp.x, {1/ln(2)}; */
 248       /* EXP2: MUL fogFactorTemp.x, fogFactorTemp.x, {1/sqrt(ln(2))}; */
 249       inst->Opcode = OPCODE_MUL;
 250       inst->DstReg.File = PROGRAM_TEMPORARY;
 251       inst->DstReg.Index = fogFactorTemp;
 252       inst->DstReg.WriteMask = WRITEMASK_X;
 253       inst->SrcReg[0].File = PROGRAM_TEMPORARY;
 254       inst->SrcReg[0].Index = fogFactorTemp;
 255       inst->SrcReg[1].File = PROGRAM_CONSTANT;
 256       inst->SrcReg[1].Index = fogConsts;
 257       inst->SrcReg[1].Swizzle
 258          = (fprog->FogOption == GL_EXP) ? SWIZZLE_X : SWIZZLE_Y;
 259       inst++;
 260       /* EX2_SAT fogFactorTemp.x, -fogFactorTemp.x; */
 261       inst->Opcode = OPCODE_EX2;
 262       inst->DstReg.File = PROGRAM_TEMPORARY;
 263       inst->DstReg.Index = fogFactorTemp;
 264       inst->DstReg.WriteMask = WRITEMASK_X;
 265       inst->SrcReg[0].File = PROGRAM_TEMPORARY;
 266       inst->SrcReg[0].Index = fogFactorTemp;
 267       inst->SrcReg[0].NegateBase = GL_TRUE;
 268       inst->SaturateMode = SATURATE_ZERO_ONE;
 269       inst++;
 270    }
 271    /* LRP result.color.xyz, fogFactorTemp.xxxx, colorTemp, fogColorRef; */
 272    inst->Opcode = OPCODE_LRP;
 273    inst->DstReg.File = PROGRAM_OUTPUT;
 274    inst->DstReg.Index = FRAG_RESULT_COLR;
 275    inst->DstReg.WriteMask = WRITEMASK_XYZ;
 276    inst->SrcReg[0].File = PROGRAM_TEMPORARY;
 277    inst->SrcReg[0].Index = fogFactorTemp;
 278    inst->SrcReg[0].Swizzle
 279       = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_X, SWIZZLE_X, SWIZZLE_X);
 280    inst->SrcReg[1].File = PROGRAM_TEMPORARY;
 281    inst->SrcReg[1].Index = colorTemp;
 282    inst->SrcReg[2].File = PROGRAM_STATE_VAR;
 283    inst->SrcReg[2].Index = fogColorRef;
 284    inst++;
 285    /* MOV result.color.w, colorTemp.x;  # copy alpha */
 286    inst->Opcode = OPCODE_MOV;
 287    inst->DstReg.File = PROGRAM_OUTPUT;
 288    inst->DstReg.Index = FRAG_RESULT_COLR;
 289    inst->DstReg.WriteMask = WRITEMASK_W;
 290    inst->SrcReg[0].File = PROGRAM_TEMPORARY;
 291    inst->SrcReg[0].Index = colorTemp;
 292    inst++;
 293    /* END; */
 294    inst->Opcode = OPCODE_END;
 295    inst++;
 296
 297    /* free old instructions */
 298    _mesa_free(fprog->Base.Instructions);
 299
 300    /* install new instructions */
 301    fprog->Base.Instructions = newInst;
 302    fprog->Base.NumInstructions = inst - newInst;
 303    fprog->Base.InputsRead |= FRAG_BIT_FOGC;
 304    /* XXX do this?  fprog->FogOption = GL_NONE; */
 305 }