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 "main/context.h"
  28 #include "main/texstate.h"
  29 #include "shader/prog_instruction.h"
  30
  31 #include "s_fragprog.h"
  32 #include "s_span.h"
  33
  34
  35 /**
  36  * Fetch a texel with given lod.
  37  * Called via machine->FetchTexelLod()
  38  */
  39 static void
  40 fetch_texel_lod( GLcontext *ctx, const GLfloat texcoord[4], GLfloat lambda,
  41                  GLuint unit, GLfloat color[4] )
  42 {
  43    GLchan rgba[4];
  44    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  45    const struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
  46
  47    if (texObj)
  48       lambda = CLAMP(lambda, texObj->MinLod, texObj->MaxLod);
  49
  50    /* XXX use a float-valued TextureSample routine here!!! */
  51    swrast->TextureSample[unit](ctx, texObj, 1, (const GLfloat (*)[4]) texcoord,
  52                                &lambda, &rgba);
  53    color[0] = CHAN_TO_FLOAT(rgba[0]);
  54    color[1] = CHAN_TO_FLOAT(rgba[1]);
  55    color[2] = CHAN_TO_FLOAT(rgba[2]);
  56    color[3] = CHAN_TO_FLOAT(rgba[3]);
  57 }
  58
  59
  60 /**
  61  * Fetch a texel with the given partial derivatives to compute a level
  62  * of detail in the mipmap.
  63  * Called via machine->FetchTexelDeriv()
  64  */
  65 static void
  66 fetch_texel_deriv( GLcontext *ctx, const GLfloat texcoord[4],
  67                    const GLfloat texdx[4], const GLfloat texdy[4],
  68                    GLfloat lodBias, GLuint unit, GLfloat color[4] )
  69 {
  70    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  71    const struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
  72    GLfloat lambda;
  73    GLchan rgba[4];
  74
  75    if (texObj) {
  76       const struct gl_texture_image *texImg = texObj->Image[0][texObj->BaseLevel];
  77       const GLfloat texW = (GLfloat) texImg->WidthScale;
  78       const GLfloat texH = (GLfloat) texImg->HeightScale;
  79
  80       lambda = _swrast_compute_lambda(texdx[0], texdy[0], /* ds/dx, ds/dy */
  81                                       texdx[1], texdy[1], /* dt/dx, dt/dy */
  82                                       texdx[3], texdy[2], /* dq/dx, dq/dy */
  83                                       texW, texH,
  84                                       texcoord[0], texcoord[1], texcoord[3],
  85                                       1.0F / texcoord[3]) + lodBias;
  86
  87       lambda = CLAMP(lambda, texObj->MinLod, texObj->MaxLod);
  88    }
  89
  90    swrast->TextureSample[unit](ctx, texObj, 1, (const GLfloat (*)[4]) texcoord,
  91                                &lambda, &rgba);
  92    color[0] = CHAN_TO_FLOAT(rgba[0]);
  93    color[1] = CHAN_TO_FLOAT(rgba[1]);
  94    color[2] = CHAN_TO_FLOAT(rgba[2]);
  95    color[3] = CHAN_TO_FLOAT(rgba[3]);
  96 }
  97
  98
  99 /**
 100  * Initialize the virtual fragment program machine state prior to running
 101  * fragment program on a fragment.  This involves initializing the input
 102  * registers, condition codes, etc.
 103  * \param machine  the virtual machine state to init
 104  * \param program  the fragment program we're about to run
 105  * \param span  the span of pixels we'll operate on
 106  * \param col  which element (column) of the span we'll operate on
 107  */
 108 static void
 109 init_machine(GLcontext *ctx, struct gl_program_machine *machine,
 110              const struct gl_fragment_program *program,
 111              const SWspan *span, GLuint col)
 112 {
 113    if (program->Base.Target == GL_FRAGMENT_PROGRAM_NV) {
 114       /* Clear temporary registers (undefined for ARB_f_p) */
 115       _mesa_bzero(machine->Temporaries,
 116                   MAX_PROGRAM_TEMPS * 4 * sizeof(GLfloat));
 117    }
 118
 119    /* Setup pointer to input attributes */
 120    machine->Attribs = span->array->attribs;
 121
 122    machine->DerivX = (GLfloat (*)[4]) span->attrStepX;
 123    machine->DerivY = (GLfloat (*)[4]) span->attrStepY;
 124    machine->NumDeriv = FRAG_ATTRIB_MAX;
 125
 126    machine->Samplers = program->Base.SamplerUnits;
 127
 128    /* if running a GLSL program (not ARB_fragment_program) */
 129    if (ctx->Shader.CurrentProgram) {
 130       /* Store front/back facing value in register FOGC.Y */
 131       machine->Attribs[FRAG_ATTRIB_FOGC][col][1] = 1.0 - span->facing;
 132       /* Note FOGC.ZW is gl_PointCoord if drawing a sprite */
 133    }
 134
 135    machine->CurElement = col;
 136
 137    /* init condition codes */
 138    machine->CondCodes[0] = COND_EQ;
 139    machine->CondCodes[1] = COND_EQ;
 140    machine->CondCodes[2] = COND_EQ;
 141    machine->CondCodes[3] = COND_EQ;
 142
 143    /* init call stack */
 144    machine->StackDepth = 0;
 145
 146    machine->FetchTexelLod = fetch_texel_lod;
 147    machine->FetchTexelDeriv = fetch_texel_deriv;
 148 }
 149
 150
 151 /**
 152  * Run fragment program on the pixels in span from 'start' to 'end' - 1.
 153  */
 154 static void
 155 run_program(GLcontext *ctx, SWspan *span, GLuint start, GLuint end)
 156 {
 157    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 158    const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
 159    const GLbitfield outputsWritten = program->Base.OutputsWritten;
 160    struct gl_program_machine *machine = &swrast->FragProgMachine;
 161    GLuint i;
 162
 163    for (i = start; i < end; i++) {
 164       if (span->array->mask[i]) {
 165          init_machine(ctx, machine, program, span, i);
 166
 167          if (_mesa_execute_program(ctx, &program->Base, machine)) {
 168
 169             /* Store result color */
 170             if (outputsWritten & (1 << FRAG_RESULT_COLR)) {
 171                COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0][i],
 172                        machine->Outputs[FRAG_RESULT_COLR]);
 173             }
 174             else {
 175                /* Multiple drawbuffers / render targets
 176                 * Note that colors beyond 0 and 1 will overwrite other
 177                 * attributes, such as FOGC, TEX0, TEX1, etc.  That's OK.
 178                 */
 179                GLuint buf;
 180                for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
 181                   if (outputsWritten & (1 << (FRAG_RESULT_DATA0 + buf))) {
 182                      COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0 + buf][i],
 183                              machine->Outputs[FRAG_RESULT_DATA0 + buf]);
 184                   }
 185                }
 186             }
 187
 188             /* Store result depth/z */
 189             if (outputsWritten & (1 << FRAG_RESULT_DEPR)) {
 190                const GLfloat depth = machine->Outputs[FRAG_RESULT_DEPR][2];
 191                if (depth <= 0.0)
 192                   span->array->z[i] = 0;
 193                else if (depth >= 1.0)
 194                   span->array->z[i] = ctx->DrawBuffer->_DepthMax;
 195                else
 196                   span->array->z[i] = IROUND(depth * ctx->DrawBuffer->_DepthMaxF);
 197             }
 198          }
 199          else {
 200             /* killed fragment */
 201             span->array->mask[i] = GL_FALSE;
 202             span->writeAll = GL_FALSE;
 203          }
 204       }
 205    }
 206 }
 207
 208
 209 /**
 210  * Execute the current fragment program for all the fragments
 211  * in the given span.
 212  */
 213 void
 214 _swrast_exec_fragment_program( GLcontext *ctx, SWspan *span )
 215 {
 216    const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
 217
 218    /* incoming colors should be floats */
 219    if (program->Base.InputsRead & FRAG_BIT_COL0) {
 220       ASSERT(span->array->ChanType == GL_FLOAT);
 221    }
 222
 223    ctx->_CurrentProgram = GL_FRAGMENT_PROGRAM_ARB; /* or NV, doesn't matter */
 224
 225    run_program(ctx, span, 0, span->end);
 226
 227    if (program->Base.OutputsWritten & (1 << FRAG_RESULT_COLR)) {
 228       span->interpMask &= ~SPAN_RGBA;
 229       span->arrayMask |= SPAN_RGBA;
 230    }
 231
 232    if (program->Base.OutputsWritten & (1 << FRAG_RESULT_DEPR)) {
 233       span->interpMask &= ~SPAN_Z;
 234       span->arrayMask |= SPAN_Z;
 235    }
 236
 237    ctx->_CurrentProgram = 0;
 238 }
 239