s_fragprog.c revision 11c581c6ce0b09dc4203a7f93ebb8f76357f19be 
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   GLfloat *wpos = span->array->attribs[FRAG_ATTRIB_WPOS][col];
148
149   if (program->Base.Target == GL_FRAGMENT_PROGRAM_NV) {
150      /* Clear temporary registers (undefined for ARB_f_p) */
151      _mesa_bzero(machine->Temporaries,
152                  MAX_PROGRAM_TEMPS * 4 * sizeof(GLfloat));
153   }
154
155   /* ARB_fragment_coord_conventions */
156   if (program->OriginUpperLeft)
157      wpos[1] = ctx->DrawBuffer->Height - 1 - wpos[1];
158   if (!program->PixelCenterInteger) {
159      wpos[0] += 0.5;
160      wpos[1] += 0.5;
161   }
162
163   /* Setup pointer to input attributes */
164   machine->Attribs = span->array->attribs;
165
166   machine->DerivX = (GLfloat (*)[4]) span->attrStepX;
167   machine->DerivY = (GLfloat (*)[4]) span->attrStepY;
168   machine->NumDeriv = FRAG_ATTRIB_MAX;
169
170   machine->Samplers = program->Base.SamplerUnits;
171
172   /* if running a GLSL program (not ARB_fragment_program) */
173   if (ctx->Shader.CurrentProgram) {
174      /* Store front/back facing value */
175      machine->Attribs[FRAG_ATTRIB_FACE][col][0] = 1.0 - span->facing;
176   }
177
178   machine->CurElement = col;
179
180   /* init condition codes */
181   machine->CondCodes[0] = COND_EQ;
182   machine->CondCodes[1] = COND_EQ;
183   machine->CondCodes[2] = COND_EQ;
184   machine->CondCodes[3] = COND_EQ;
185
186   /* init call stack */
187   machine->StackDepth = 0;
188
189   machine->FetchTexelLod = fetch_texel_lod;
190   machine->FetchTexelDeriv = fetch_texel_deriv;
191}
192
193
194/**
195 * Run fragment program on the pixels in span from 'start' to 'end' - 1.
196 */
197static void
198run_program(GLcontext *ctx, SWspan *span, GLuint start, GLuint end)
199{
200   SWcontext *swrast = SWRAST_CONTEXT(ctx);
201   const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
202   const GLbitfield64 outputsWritten = program->Base.OutputsWritten;
203   struct gl_program_machine *machine = &swrast->FragProgMachine;
204   GLuint i;
205
206   for (i = start; i < end; i++) {
207      if (span->array->mask[i]) {
208         init_machine(ctx, machine, program, span, i);
209
210         if (_mesa_execute_program(ctx, &program->Base, machine)) {
211
212            /* Store result color */
213	    if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
214               COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0][i],
215                       machine->Outputs[FRAG_RESULT_COLOR]);
216            }
217            else {
218               /* Multiple drawbuffers / render targets
219                * Note that colors beyond 0 and 1 will overwrite other
220                * attributes, such as FOGC, TEX0, TEX1, etc.  That's OK.
221                */
222               GLuint buf;
223               for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
224                  if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DATA0 + buf)) {
225                     COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0 + buf][i],
226                             machine->Outputs[FRAG_RESULT_DATA0 + buf]);
227                  }
228               }
229            }
230
231            /* Store result depth/z */
232            if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
233               const GLfloat depth = machine->Outputs[FRAG_RESULT_DEPTH][2];
234               if (depth <= 0.0)
235                  span->array->z[i] = 0;
236               else if (depth >= 1.0)
237                  span->array->z[i] = ctx->DrawBuffer->_DepthMax;
238               else
239                  span->array->z[i] = IROUND(depth * ctx->DrawBuffer->_DepthMaxF);
240            }
241         }
242         else {
243            /* killed fragment */
244            span->array->mask[i] = GL_FALSE;
245            span->writeAll = GL_FALSE;
246         }
247      }
248   }
249}
250
251
252/**
253 * Execute the current fragment program for all the fragments
254 * in the given span.
255 */
256void
257_swrast_exec_fragment_program( GLcontext *ctx, SWspan *span )
258{
259   const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
260
261   /* incoming colors should be floats */
262   if (program->Base.InputsRead & FRAG_BIT_COL0) {
263      ASSERT(span->array->ChanType == GL_FLOAT);
264   }
265
266   run_program(ctx, span, 0, span->end);
267
268   if (program->Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
269      span->interpMask &= ~SPAN_RGBA;
270      span->arrayMask |= SPAN_RGBA;
271   }
272
273   if (program->Base.OutputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
274      span->interpMask &= ~SPAN_Z;
275      span->arrayMask |= SPAN_Z;
276   }
277}
278
279