s_fragprog.c revision 4a49301e 
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 "shader/prog_instruction.h"
29
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 */
38static INLINE void
39swizzle_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 */
64static void
65fetch_texel_lod( GLcontext *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->MinLod, texObj->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 */
94static void
95fetch_texel_deriv( GLcontext *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 GLfloat texW = (GLfloat) texImg->WidthScale;
107      const GLfloat texH = (GLfloat) texImg->HeightScale;
108      GLfloat lambda;
109      GLfloat rgba[4];
110
111      lambda = _swrast_compute_lambda(texdx[0], texdy[0], /* ds/dx, ds/dy */
112                                      texdx[1], texdy[1], /* dt/dx, dt/dy */
113                                      texdx[3], texdy[3], /* dq/dx, dq/dy */
114                                      texW, texH,
115                                      texcoord[0], texcoord[1], texcoord[3],
116                                      1.0F / texcoord[3]);
117
118      lambda += lodBias + texUnit->LodBias + texObj->LodBias;
119
120      lambda = CLAMP(lambda, texObj->MinLod, texObj->MaxLod);
121
122      swrast->TextureSample[unit](ctx, texObj, 1,
123                                  (const GLfloat (*)[4]) texcoord,
124                                  &lambda, &rgba);
125      swizzle_texel(rgba, color, texObj->_Swizzle);
126   }
127   else {
128      ASSIGN_4V(color, 0.0F, 0.0F, 0.0F, 1.0F);
129   }
130}
131
132
133/**
134 * Initialize the virtual fragment program machine state prior to running
135 * fragment program on a fragment.  This involves initializing the input
136 * registers, condition codes, etc.
137 * \param machine  the virtual machine state to init
138 * \param program  the fragment program we're about to run
139 * \param span  the span of pixels we'll operate on
140 * \param col  which element (column) of the span we'll operate on
141 */
142static void
143init_machine(GLcontext *ctx, struct gl_program_machine *machine,
144             const struct gl_fragment_program *program,
145             const SWspan *span, GLuint col)
146{
147   if (program->Base.Target == GL_FRAGMENT_PROGRAM_NV) {
148      /* Clear temporary registers (undefined for ARB_f_p) */
149      _mesa_bzero(machine->Temporaries,
150                  MAX_PROGRAM_TEMPS * 4 * sizeof(GLfloat));
151   }
152
153   /* Setup pointer to input attributes */
154   machine->Attribs = span->array->attribs;
155
156   machine->DerivX = (GLfloat (*)[4]) span->attrStepX;
157   machine->DerivY = (GLfloat (*)[4]) span->attrStepY;
158   machine->NumDeriv = FRAG_ATTRIB_MAX;
159
160   machine->Samplers = program->Base.SamplerUnits;
161
162   /* if running a GLSL program (not ARB_fragment_program) */
163   if (ctx->Shader.CurrentProgram) {
164      /* Store front/back facing value */
165      machine->Attribs[FRAG_ATTRIB_FACE][col][0] = 1.0 - span->facing;
166   }
167
168   machine->CurElement = col;
169
170   /* init condition codes */
171   machine->CondCodes[0] = COND_EQ;
172   machine->CondCodes[1] = COND_EQ;
173   machine->CondCodes[2] = COND_EQ;
174   machine->CondCodes[3] = COND_EQ;
175
176   /* init call stack */
177   machine->StackDepth = 0;
178
179   machine->FetchTexelLod = fetch_texel_lod;
180   machine->FetchTexelDeriv = fetch_texel_deriv;
181}
182
183
184/**
185 * Run fragment program on the pixels in span from 'start' to 'end' - 1.
186 */
187static void
188run_program(GLcontext *ctx, SWspan *span, GLuint start, GLuint end)
189{
190   SWcontext *swrast = SWRAST_CONTEXT(ctx);
191   const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
192   const GLbitfield64 outputsWritten = program->Base.OutputsWritten;
193   struct gl_program_machine *machine = &swrast->FragProgMachine;
194   GLuint i;
195
196   for (i = start; i < end; i++) {
197      if (span->array->mask[i]) {
198         init_machine(ctx, machine, program, span, i);
199
200         if (_mesa_execute_program(ctx, &program->Base, machine)) {
201
202            /* Store result color */
203	    if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
204               COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0][i],
205                       machine->Outputs[FRAG_RESULT_COLOR]);
206            }
207            else {
208               /* Multiple drawbuffers / render targets
209                * Note that colors beyond 0 and 1 will overwrite other
210                * attributes, such as FOGC, TEX0, TEX1, etc.  That's OK.
211                */
212               GLuint buf;
213               for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
214                  if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DATA0 + buf)) {
215                     COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0 + buf][i],
216                             machine->Outputs[FRAG_RESULT_DATA0 + buf]);
217                  }
218               }
219            }
220
221            /* Store result depth/z */
222            if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
223               const GLfloat depth = machine->Outputs[FRAG_RESULT_DEPTH][2];
224               if (depth <= 0.0)
225                  span->array->z[i] = 0;
226               else if (depth >= 1.0)
227                  span->array->z[i] = ctx->DrawBuffer->_DepthMax;
228               else
229                  span->array->z[i] = IROUND(depth * ctx->DrawBuffer->_DepthMaxF);
230            }
231         }
232         else {
233            /* killed fragment */
234            span->array->mask[i] = GL_FALSE;
235            span->writeAll = GL_FALSE;
236         }
237      }
238   }
239}
240
241
242/**
243 * Execute the current fragment program for all the fragments
244 * in the given span.
245 */
246void
247_swrast_exec_fragment_program( GLcontext *ctx, SWspan *span )
248{
249   const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
250
251   /* incoming colors should be floats */
252   if (program->Base.InputsRead & FRAG_BIT_COL0) {
253      ASSERT(span->array->ChanType == GL_FLOAT);
254   }
255
256   run_program(ctx, span, 0, span->end);
257
258   if (program->Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
259      span->interpMask &= ~SPAN_RGBA;
260      span->arrayMask |= SPAN_RGBA;
261   }
262
263   if (program->Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
264      span->interpMask &= ~SPAN_Z;
265      span->arrayMask |= SPAN_Z;
266   }
267}
268
269