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