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