s_fragprog.c revision ad935c3f4708417641dd3c257912ccce11485acc 
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 * Apply texture object's swizzle (X/Y/Z/W/0/1) to incoming 'texel'
37 * and return results in 'colorOut'.
38 */
39static INLINE void
40swizzle_texel(const GLfloat texel[4], GLfloat colorOut[4], GLuint swizzle)
41{
42   if (swizzle == SWIZZLE_NOOP) {
43      COPY_4V(colorOut, texel);
44   }
45   else {
46      GLfloat vector[6];
47      vector[SWIZZLE_X] = texel[0];
48      vector[SWIZZLE_Y] = texel[1];
49      vector[SWIZZLE_Z] = texel[2];
50      vector[SWIZZLE_W] = texel[3];
51      vector[SWIZZLE_ZERO] = 0.0F;
52      vector[SWIZZLE_ONE] = 1.0F;
53      colorOut[0] = vector[GET_SWZ(swizzle, 0)];
54      colorOut[1] = vector[GET_SWZ(swizzle, 1)];
55      colorOut[2] = vector[GET_SWZ(swizzle, 2)];
56      colorOut[3] = vector[GET_SWZ(swizzle, 3)];
57   }
58}
59
60
61/**
62 * Fetch a texel with given lod.
63 * Called via machine->FetchTexelLod()
64 */
65static void
66fetch_texel_lod( GLcontext *ctx, const GLfloat texcoord[4], GLfloat lambda,
67                 GLuint unit, GLfloat color[4] )
68{
69   const struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
70
71   if (texObj) {
72      SWcontext *swrast = SWRAST_CONTEXT(ctx);
73      GLfloat rgba[4];
74
75      lambda = CLAMP(lambda, texObj->MinLod, texObj->MaxLod);
76
77      swrast->TextureSample[unit](ctx, texObj, 1,
78                                  (const GLfloat (*)[4]) texcoord,
79                                  &lambda, &rgba);
80      swizzle_texel(rgba, color, texObj->_Swizzle);
81   }
82   else {
83      ASSIGN_4V(color, 0.0F, 0.0F, 0.0F, 1.0F);
84   }
85}
86
87
88/**
89 * Fetch a texel with the given partial derivatives to compute a level
90 * of detail in the mipmap.
91 * Called via machine->FetchTexelDeriv()
92 */
93static void
94fetch_texel_deriv( GLcontext *ctx, const GLfloat texcoord[4],
95                   const GLfloat texdx[4], const GLfloat texdy[4],
96                   GLfloat lodBias, GLuint unit, GLfloat color[4] )
97{
98   SWcontext *swrast = SWRAST_CONTEXT(ctx);
99   const struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
100
101   if (texObj) {
102      const struct gl_texture_image *texImg =
103         texObj->Image[0][texObj->BaseLevel];
104      const GLfloat texW = (GLfloat) texImg->WidthScale;
105      const GLfloat texH = (GLfloat) texImg->HeightScale;
106      GLfloat lambda;
107      GLfloat rgba[4];
108
109      lambda = _swrast_compute_lambda(texdx[0], texdy[0], /* ds/dx, ds/dy */
110                                      texdx[1], texdy[1], /* dt/dx, dt/dy */
111                                      texdx[3], texdy[3], /* dq/dx, dq/dy */
112                                      texW, texH,
113                                      texcoord[0], texcoord[1], texcoord[3],
114                                      1.0F / texcoord[3]) + lodBias;
115
116      lambda = CLAMP(lambda, texObj->MinLod, texObj->MaxLod);
117
118      swrast->TextureSample[unit](ctx, texObj, 1,
119                                  (const GLfloat (*)[4]) texcoord,
120                                  &lambda, &rgba);
121      swizzle_texel(rgba, color, texObj->_Swizzle);
122   }
123   else {
124      ASSIGN_4V(color, 0.0F, 0.0F, 0.0F, 1.0F);
125   }
126}
127
128
129/**
130 * Initialize the virtual fragment program machine state prior to running
131 * fragment program on a fragment.  This involves initializing the input
132 * registers, condition codes, etc.
133 * \param machine  the virtual machine state to init
134 * \param program  the fragment program we're about to run
135 * \param span  the span of pixels we'll operate on
136 * \param col  which element (column) of the span we'll operate on
137 */
138static void
139init_machine(GLcontext *ctx, struct gl_program_machine *machine,
140             const struct gl_fragment_program *program,
141             const SWspan *span, GLuint col)
142{
143   if (program->Base.Target == GL_FRAGMENT_PROGRAM_NV) {
144      /* Clear temporary registers (undefined for ARB_f_p) */
145      _mesa_bzero(machine->Temporaries,
146                  MAX_PROGRAM_TEMPS * 4 * sizeof(GLfloat));
147   }
148
149   /* Setup pointer to input attributes */
150   machine->Attribs = span->array->attribs;
151
152   machine->DerivX = (GLfloat (*)[4]) span->attrStepX;
153   machine->DerivY = (GLfloat (*)[4]) span->attrStepY;
154   machine->NumDeriv = FRAG_ATTRIB_MAX;
155
156   machine->Samplers = program->Base.SamplerUnits;
157
158   /* if running a GLSL program (not ARB_fragment_program) */
159   if (ctx->Shader.CurrentProgram) {
160      /* Store front/back facing value in register FOGC.Y */
161      machine->Attribs[FRAG_ATTRIB_FOGC][col][1] = 1.0 - span->facing;
162      /* Note FOGC.ZW is gl_PointCoord if drawing a sprite */
163   }
164
165   machine->CurElement = col;
166
167   /* init condition codes */
168   machine->CondCodes[0] = COND_EQ;
169   machine->CondCodes[1] = COND_EQ;
170   machine->CondCodes[2] = COND_EQ;
171   machine->CondCodes[3] = COND_EQ;
172
173   /* init call stack */
174   machine->StackDepth = 0;
175
176   machine->FetchTexelLod = fetch_texel_lod;
177   machine->FetchTexelDeriv = fetch_texel_deriv;
178}
179
180
181/**
182 * Run fragment program on the pixels in span from 'start' to 'end' - 1.
183 */
184static void
185run_program(GLcontext *ctx, SWspan *span, GLuint start, GLuint end)
186{
187   SWcontext *swrast = SWRAST_CONTEXT(ctx);
188   const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
189   const GLbitfield outputsWritten = program->Base.OutputsWritten;
190   struct gl_program_machine *machine = &swrast->FragProgMachine;
191   GLuint i;
192
193   for (i = start; i < end; i++) {
194      if (span->array->mask[i]) {
195         init_machine(ctx, machine, program, span, i);
196
197         if (_mesa_execute_program(ctx, &program->Base, machine)) {
198
199            /* Store result color */
200            if (outputsWritten & (1 << FRAG_RESULT_COLOR)) {
201               COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0][i],
202                       machine->Outputs[FRAG_RESULT_COLOR]);
203            }
204            else {
205               /* Multiple drawbuffers / render targets
206                * Note that colors beyond 0 and 1 will overwrite other
207                * attributes, such as FOGC, TEX0, TEX1, etc.  That's OK.
208                */
209               GLuint buf;
210               for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
211                  if (outputsWritten & (1 << (FRAG_RESULT_DATA0 + buf))) {
212                     COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0 + buf][i],
213                             machine->Outputs[FRAG_RESULT_DATA0 + buf]);
214                  }
215               }
216            }
217
218            /* Store result depth/z */
219            if (outputsWritten & (1 << FRAG_RESULT_DEPTH)) {
220               const GLfloat depth = machine->Outputs[FRAG_RESULT_DEPTH][2];
221               if (depth <= 0.0)
222                  span->array->z[i] = 0;
223               else if (depth >= 1.0)
224                  span->array->z[i] = ctx->DrawBuffer->_DepthMax;
225               else
226                  span->array->z[i] = IROUND(depth * ctx->DrawBuffer->_DepthMaxF);
227            }
228         }
229         else {
230            /* killed fragment */
231            span->array->mask[i] = GL_FALSE;
232            span->writeAll = GL_FALSE;
233         }
234      }
235   }
236}
237
238
239/**
240 * Execute the current fragment program for all the fragments
241 * in the given span.
242 */
243void
244_swrast_exec_fragment_program( GLcontext *ctx, SWspan *span )
245{
246   const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
247
248   /* incoming colors should be floats */
249   if (program->Base.InputsRead & FRAG_BIT_COL0) {
250      ASSERT(span->array->ChanType == GL_FLOAT);
251   }
252
253   run_program(ctx, span, 0, span->end);
254
255   if (program->Base.OutputsWritten & (1 << FRAG_RESULT_COLOR)) {
256      span->interpMask &= ~SPAN_RGBA;
257      span->arrayMask |= SPAN_RGBA;
258   }
259
260   if (program->Base.OutputsWritten & (1 << FRAG_RESULT_DEPTH)) {
261      span->interpMask &= ~SPAN_Z;
262      span->arrayMask |= SPAN_Z;
263   }
264}
265
266