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 /**
  35  * Apply texture object's swizzle (X/Y/Z/W/0/1) to incoming 'texel'
  36  * and return results in 'colorOut'.
  37  */
  38 static inline void
  39 swizzle_texel(const GLfloat texel[4], GLfloat colorOut[4], GLuint swizzle)
  40 {
  41    if (swizzle == SWIZZLE_NOOP) {
  42       COPY_4V(colorOut, texel);
  43    }
  44    else {
  45       GLfloat vector[6];
  46       vector[SWIZZLE_X] = texel[0];
  47       vector[SWIZZLE_Y] = texel[1];
  48       vector[SWIZZLE_Z] = texel[2];
  49       vector[SWIZZLE_W] = texel[3];
  50       vector[SWIZZLE_ZERO] = 0.0F;
  51       vector[SWIZZLE_ONE] = 1.0F;
  52       colorOut[0] = vector[GET_SWZ(swizzle, 0)];
  53       colorOut[1] = vector[GET_SWZ(swizzle, 1)];
  54       colorOut[2] = vector[GET_SWZ(swizzle, 2)];
  55       colorOut[3] = vector[GET_SWZ(swizzle, 3)];
  56    }
  57 }
  58
  59
  60 /**
  61  * Fetch a texel with given lod.
  62  * Called via machine->FetchTexelLod()
  63  */
  64 static void
  65 fetch_texel_lod( struct gl_context *ctx, const GLfloat texcoord[4], GLfloat lambda,
  66                  GLuint unit, GLfloat color[4] )
  67 {
  68    const struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
  69
  70    if (texObj) {
  71       SWcontext *swrast = SWRAST_CONTEXT(ctx);
  72       GLfloat rgba[4];
  73
  74       lambda = CLAMP(lambda, texObj->Sampler.MinLod, texObj->Sampler.MaxLod);
  75
  76       swrast->TextureSample[unit](ctx, texObj, 1,
  77                                   (const GLfloat (*)[4]) texcoord,
  78                                   &lambda, &rgba);
  79       swizzle_texel(rgba, color, texObj->_Swizzle);
  80    }
  81    else {
  82       ASSIGN_4V(color, 0.0F, 0.0F, 0.0F, 1.0F);
  83    }
  84 }
  85
  86
  87 /**
  88  * Fetch a texel with the given partial derivatives to compute a level
  89  * of detail in the mipmap.
  90  * Called via machine->FetchTexelDeriv()
  91  * \param lodBias  the lod bias which may be specified by a TXB instruction,
  92  *                 otherwise zero.
  93  */
  94 static void
  95 fetch_texel_deriv( struct gl_context *ctx, const GLfloat texcoord[4],
  96                    const GLfloat texdx[4], const GLfloat texdy[4],
  97                    GLfloat lodBias, GLuint unit, GLfloat color[4] )
  98 {
  99    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 100    const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 101    const struct gl_texture_object *texObj = texUnit->_Current;
 102
 103    if (texObj) {
 104       const struct gl_texture_image *texImg =
 105          texObj->Image[0][texObj->BaseLevel];
 106       const struct swrast_texture_image *swImg =
 107          swrast_texture_image_const(texImg);
 108       const GLfloat texW = (GLfloat) swImg->WidthScale;
 109       const GLfloat texH = (GLfloat) swImg->HeightScale;
 110       GLfloat lambda;
 111       GLfloat rgba[4];
 112
 113       lambda = _swrast_compute_lambda(texdx[0], texdy[0], /* ds/dx, ds/dy */
 114                                       texdx[1], texdy[1], /* dt/dx, dt/dy */
 115                                       texdx[3], texdy[3], /* dq/dx, dq/dy */
 116                                       texW, texH,
 117                                       texcoord[0], texcoord[1], texcoord[3],
 118                                       1.0F / texcoord[3]);
 119
 120       lambda += lodBias + texUnit->LodBias + texObj->Sampler.LodBias;
 121
 122       lambda = CLAMP(lambda, texObj->Sampler.MinLod, texObj->Sampler.MaxLod);
 123
 124       swrast->TextureSample[unit](ctx, texObj, 1,
 125                                   (const GLfloat (*)[4]) texcoord,
 126                                   &lambda, &rgba);
 127       swizzle_texel(rgba, color, texObj->_Swizzle);
 128    }
 129    else {
 130       ASSIGN_4V(color, 0.0F, 0.0F, 0.0F, 1.0F);
 131    }
 132 }
 133
 134
 135 /**
 136  * Initialize the virtual fragment program machine state prior to running
 137  * fragment program on a fragment.  This involves initializing the input
 138  * registers, condition codes, etc.
 139  * \param machine  the virtual machine state to init
 140  * \param program  the fragment program we're about to run
 141  * \param span  the span of pixels we'll operate on
 142  * \param col  which element (column) of the span we'll operate on
 143  */
 144 static void
 145 init_machine(struct gl_context *ctx, struct gl_program_machine *machine,
 146              const struct gl_fragment_program *program,
 147              const SWspan *span, GLuint col)
 148 {
 149    GLfloat *wpos = span->array->attribs[FRAG_ATTRIB_WPOS][col];
 150
 151    if (program->Base.Target == GL_FRAGMENT_PROGRAM_NV) {
 152       /* Clear temporary registers (undefined for ARB_f_p) */
 153       memset(machine->Temporaries, 0, MAX_PROGRAM_TEMPS * 4 * sizeof(GLfloat));
 154    }
 155
 156    /* ARB_fragment_coord_conventions */
 157    if (program->OriginUpperLeft)
 158       wpos[1] = ctx->DrawBuffer->Height - 1 - wpos[1];
 159    if (!program->PixelCenterInteger) {
 160       wpos[0] += 0.5F;
 161       wpos[1] += 0.5F;
 162    }
 163
 164    /* Setup pointer to input attributes */
 165    machine->Attribs = span->array->attribs;
 166
 167    machine->DerivX = (GLfloat (*)[4]) span->attrStepX;
 168    machine->DerivY = (GLfloat (*)[4]) span->attrStepY;
 169    machine->NumDeriv = FRAG_ATTRIB_MAX;
 170
 171    machine->Samplers = program->Base.SamplerUnits;
 172
 173    /* if running a GLSL program (not ARB_fragment_program) */
 174    if (ctx->Shader.CurrentFragmentProgram) {
 175       /* Store front/back facing value */
 176       machine->Attribs[FRAG_ATTRIB_FACE][col][0] = 1.0F - span->facing;
 177    }
 178
 179    machine->CurElement = col;
 180
 181    /* init condition codes */
 182    machine->CondCodes[0] = COND_EQ;
 183    machine->CondCodes[1] = COND_EQ;
 184    machine->CondCodes[2] = COND_EQ;
 185    machine->CondCodes[3] = COND_EQ;
 186
 187    /* init call stack */
 188    machine->StackDepth = 0;
 189
 190    machine->FetchTexelLod = fetch_texel_lod;
 191    machine->FetchTexelDeriv = fetch_texel_deriv;
 192 }
 193
 194
 195 /**
 196  * Run fragment program on the pixels in span from 'start' to 'end' - 1.
 197  */
 198 static void
 199 run_program(struct gl_context *ctx, SWspan *span, GLuint start, GLuint end)
 200 {
 201    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 202    const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
 203    const GLbitfield64 outputsWritten = program->Base.OutputsWritten;
 204    struct gl_program_machine *machine = &swrast->FragProgMachine;
 205    GLuint i;
 206
 207    for (i = start; i < end; i++) {
 208       if (span->array->mask[i]) {
 209          init_machine(ctx, machine, program, span, i);
 210
 211          if (_mesa_execute_program(ctx, &program->Base, machine)) {
 212
 213             /* Store result color */
 214             if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
 215                COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0][i],
 216                        machine->Outputs[FRAG_RESULT_COLOR]);
 217             }
 218             else {
 219                /* Multiple drawbuffers / render targets
 220                 * Note that colors beyond 0 and 1 will overwrite other
 221                 * attributes, such as FOGC, TEX0, TEX1, etc.  That's OK.
 222                 */
 223                GLuint buf;
 224                for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
 225                   if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DATA0 + buf)) {
 226                      COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0 + buf][i],
 227                              machine->Outputs[FRAG_RESULT_DATA0 + buf]);
 228                   }
 229                }
 230             }
 231
 232             /* Store result depth/z */
 233             if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
 234                const GLfloat depth = machine->Outputs[FRAG_RESULT_DEPTH][2];
 235                if (depth <= 0.0)
 236                   span->array->z[i] = 0;
 237                else if (depth >= 1.0)
 238                   span->array->z[i] = ctx->DrawBuffer->_DepthMax;
 239                else
 240                   span->array->z[i] =
 241                      (GLuint) (depth * ctx->DrawBuffer->_DepthMaxF + 0.5F);
 242             }
 243          }
 244          else {
 245             /* killed fragment */
 246             span->array->mask[i] = GL_FALSE;
 247             span->writeAll = GL_FALSE;
 248          }
 249       }
 250    }
 251 }
 252
 253
 254 /**
 255  * Execute the current fragment program for all the fragments
 256  * in the given span.
 257  */
 258 void
 259 _swrast_exec_fragment_program( struct gl_context *ctx, SWspan *span )
 260 {
 261    const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
 262
 263    /* incoming colors should be floats */
 264    if (program->Base.InputsRead & FRAG_BIT_COL0) {
 265       ASSERT(span->array->ChanType == GL_FLOAT);
 266    }
 267
 268    run_program(ctx, span, 0, span->end);
 269
 270    if (program->Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
 271       span->interpMask &= ~SPAN_RGBA;
 272       span->arrayMask |= SPAN_RGBA;
 273    }
 274
 275    if (program->Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
 276       span->interpMask &= ~SPAN_Z;
 277       span->arrayMask |= SPAN_Z;
 278    }
 279 }
 280