src/mesa/swrast/s_fragprog.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.0.3
   4  *
   5  * Copyright (C) 1999-2007  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 #include "main/glheader.h"
  26 #include "main/colormac.h"
  27 #include "program/prog_instruction.h"
  28
  29 #include "s_context.h"
  30 #include "s_fragprog.h"
  31 #include "s_span.h"
  32
  33 /**
  34  * \brief Should swrast use a fragment program?
  35  *
  36  * \return true if the current fragment program exists and is not the fixed
  37  *         function fragment program
  38  */
  39 GLboolean
  40 _swrast_use_fragment_program(struct gl_context *ctx)
  41 {
  42    struct gl_fragment_program *fp = ctx->FragmentProgram._Current;
  43    return fp && !(fp == ctx->FragmentProgram._TexEnvProgram
  44                   && fp->Base.NumInstructions == 0);
  45 }
  46
  47 /**
  48  * Apply texture object's swizzle (X/Y/Z/W/0/1) to incoming 'texel'
  49  * and return results in 'colorOut'.
  50  */
  51 static inline void
  52 swizzle_texel(const GLfloat texel[4], GLfloat colorOut[4], GLuint swizzle)
  53 {
  54    if (swizzle == SWIZZLE_NOOP) {
  55       COPY_4V(colorOut, texel);
  56    }
  57    else {
  58       GLfloat vector[6];
  59       vector[SWIZZLE_X] = texel[0];
  60       vector[SWIZZLE_Y] = texel[1];
  61       vector[SWIZZLE_Z] = texel[2];
  62       vector[SWIZZLE_W] = texel[3];
  63       vector[SWIZZLE_ZERO] = 0.0F;
  64       vector[SWIZZLE_ONE] = 1.0F;
  65       colorOut[0] = vector[GET_SWZ(swizzle, 0)];
  66       colorOut[1] = vector[GET_SWZ(swizzle, 1)];
  67       colorOut[2] = vector[GET_SWZ(swizzle, 2)];
  68       colorOut[3] = vector[GET_SWZ(swizzle, 3)];
  69    }
  70 }
  71
  72
  73 /**
  74  * Fetch a texel with given lod.
  75  * Called via machine->FetchTexelLod()
  76  */
  77 static void
  78 fetch_texel_lod( struct gl_context *ctx, const GLfloat texcoord[4], GLfloat lambda,
  79                  GLuint unit, GLfloat color[4] )
  80 {
  81    const struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
  82
  83    if (texObj) {
  84       SWcontext *swrast = SWRAST_CONTEXT(ctx);
  85       GLfloat rgba[4];
  86
  87       lambda = CLAMP(lambda, texObj->Sampler.MinLod, texObj->Sampler.MaxLod);
  88
  89       swrast->TextureSample[unit](ctx, texObj, 1,
  90                                   (const GLfloat (*)[4]) texcoord,
  91                                   &lambda, &rgba);
  92       swizzle_texel(rgba, color, texObj->_Swizzle);
  93    }
  94    else {
  95       ASSIGN_4V(color, 0.0F, 0.0F, 0.0F, 1.0F);
  96    }
  97 }
  98
  99
 100 /**
 101  * Fetch a texel with the given partial derivatives to compute a level
 102  * of detail in the mipmap.
 103  * Called via machine->FetchTexelDeriv()
 104  * \param lodBias  the lod bias which may be specified by a TXB instruction,
 105  *                 otherwise zero.
 106  */
 107 static void
 108 fetch_texel_deriv( struct gl_context *ctx, const GLfloat texcoord[4],
 109                    const GLfloat texdx[4], const GLfloat texdy[4],
 110                    GLfloat lodBias, GLuint unit, GLfloat color[4] )
 111 {
 112    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 113    const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 114    const struct gl_texture_object *texObj = texUnit->_Current;
 115
 116    if (texObj) {
 117       const struct gl_texture_image *texImg =
 118          texObj->Image[0][texObj->BaseLevel];
 119       const struct swrast_texture_image *swImg =
 120          swrast_texture_image_const(texImg);
 121       const GLfloat texW = (GLfloat) swImg->WidthScale;
 122       const GLfloat texH = (GLfloat) swImg->HeightScale;
 123       GLfloat lambda;
 124       GLfloat rgba[4];
 125
 126       lambda = _swrast_compute_lambda(texdx[0], texdy[0], /* ds/dx, ds/dy */
 127                                       texdx[1], texdy[1], /* dt/dx, dt/dy */
 128                                       texdx[3], texdy[3], /* dq/dx, dq/dy */
 129                                       texW, texH,
 130                                       texcoord[0], texcoord[1], texcoord[3],
 131                                       1.0F / texcoord[3]);
 132
 133       lambda += lodBias + texUnit->LodBias + texObj->Sampler.LodBias;
 134
 135       lambda = CLAMP(lambda, texObj->Sampler.MinLod, texObj->Sampler.MaxLod);
 136
 137       swrast->TextureSample[unit](ctx, texObj, 1,
 138                                   (const GLfloat (*)[4]) texcoord,
 139                                   &lambda, &rgba);
 140       swizzle_texel(rgba, color, texObj->_Swizzle);
 141    }
 142    else {
 143       ASSIGN_4V(color, 0.0F, 0.0F, 0.0F, 1.0F);
 144    }
 145 }
 146
 147
 148 /**
 149  * Initialize the virtual fragment program machine state prior to running
 150  * fragment program on a fragment.  This involves initializing the input
 151  * registers, condition codes, etc.
 152  * \param machine  the virtual machine state to init
 153  * \param program  the fragment program we're about to run
 154  * \param span  the span of pixels we'll operate on
 155  * \param col  which element (column) of the span we'll operate on
 156  */
 157 static void
 158 init_machine(struct gl_context *ctx, struct gl_program_machine *machine,
 159              const struct gl_fragment_program *program,
 160              const SWspan *span, GLuint col)
 161 {
 162    GLfloat *wpos = span->array->attribs[FRAG_ATTRIB_WPOS][col];
 163
 164    if (program->Base.Target == GL_FRAGMENT_PROGRAM_NV) {
 165       /* Clear temporary registers (undefined for ARB_f_p) */
 166       memset(machine->Temporaries, 0, MAX_PROGRAM_TEMPS * 4 * sizeof(GLfloat));
 167    }
 168
 169    /* ARB_fragment_coord_conventions */
 170    if (program->OriginUpperLeft)
 171       wpos[1] = ctx->DrawBuffer->Height - 1 - wpos[1];
 172    if (!program->PixelCenterInteger) {
 173       wpos[0] += 0.5F;
 174       wpos[1] += 0.5F;
 175    }
 176
 177    /* Setup pointer to input attributes */
 178    machine->Attribs = span->array->attribs;
 179
 180    machine->DerivX = (GLfloat (*)[4]) span->attrStepX;
 181    machine->DerivY = (GLfloat (*)[4]) span->attrStepY;
 182    machine->NumDeriv = FRAG_ATTRIB_MAX;
 183
 184    machine->Samplers = program->Base.SamplerUnits;
 185
 186    /* if running a GLSL program (not ARB_fragment_program) */
 187    if (ctx->Shader.CurrentFragmentProgram) {
 188       /* Store front/back facing value */
 189       machine->Attribs[FRAG_ATTRIB_FACE][col][0] = 1.0F - span->facing;
 190    }
 191
 192    machine->CurElement = col;
 193
 194    /* init condition codes */
 195    machine->CondCodes[0] = COND_EQ;
 196    machine->CondCodes[1] = COND_EQ;
 197    machine->CondCodes[2] = COND_EQ;
 198    machine->CondCodes[3] = COND_EQ;
 199
 200    /* init call stack */
 201    machine->StackDepth = 0;
 202
 203    machine->FetchTexelLod = fetch_texel_lod;
 204    machine->FetchTexelDeriv = fetch_texel_deriv;
 205 }
 206
 207
 208 /**
 209  * Run fragment program on the pixels in span from 'start' to 'end' - 1.
 210  */
 211 static void
 212 run_program(struct gl_context *ctx, SWspan *span, GLuint start, GLuint end)
 213 {
 214    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 215    const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
 216    const GLbitfield64 outputsWritten = program->Base.OutputsWritten;
 217    struct gl_program_machine *machine = &swrast->FragProgMachine;
 218    GLuint i;
 219
 220    for (i = start; i < end; i++) {
 221       if (span->array->mask[i]) {
 222          init_machine(ctx, machine, program, span, i);
 223
 224          if (_mesa_execute_program(ctx, &program->Base, machine)) {
 225
 226             /* Store result color */
 227             if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
 228                COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0][i],
 229                        machine->Outputs[FRAG_RESULT_COLOR]);
 230             }
 231             else {
 232                /* Multiple drawbuffers / render targets
 233                 * Note that colors beyond 0 and 1 will overwrite other
 234                 * attributes, such as FOGC, TEX0, TEX1, etc.  That's OK.
 235                 */
 236                GLuint buf;
 237                for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
 238                   if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DATA0 + buf)) {
 239                      COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0 + buf][i],
 240                              machine->Outputs[FRAG_RESULT_DATA0 + buf]);
 241                   }
 242                }
 243             }
 244
 245             /* Store result depth/z */
 246             if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
 247                const GLfloat depth = machine->Outputs[FRAG_RESULT_DEPTH][2];
 248                if (depth <= 0.0)
 249                   span->array->z[i] = 0;
 250                else if (depth >= 1.0)
 251                   span->array->z[i] = ctx->DrawBuffer->_DepthMax;
 252                else
 253                   span->array->z[i] =
 254                      (GLuint) (depth * ctx->DrawBuffer->_DepthMaxF + 0.5F);
 255             }
 256          }
 257          else {
 258             /* killed fragment */
 259             span->array->mask[i] = GL_FALSE;
 260             span->writeAll = GL_FALSE;
 261          }
 262       }
 263    }
 264 }
 265
 266
 267 /**
 268  * Execute the current fragment program for all the fragments
 269  * in the given span.
 270  */
 271 void
 272 _swrast_exec_fragment_program( struct gl_context *ctx, SWspan *span )
 273 {
 274    const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
 275
 276    /* incoming colors should be floats */
 277    if (program->Base.InputsRead & FRAG_BIT_COL0) {
 278       ASSERT(span->array->ChanType == GL_FLOAT);
 279    }
 280
 281    run_program(ctx, span, 0, span->end);
 282
 283    if (program->Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
 284       span->interpMask &= ~SPAN_RGBA;
 285       span->arrayMask |= SPAN_RGBA;
 286    }
 287
 288    if (program->Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
 289       span->interpMask &= ~SPAN_Z;
 290       span->arrayMask |= SPAN_Z;
 291    }
 292 }
 293