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