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