aboutsummaryrefslogtreecommitdiffstats
path: root/src/mesa/swrast/s_fragprog.c
blob: bf7a1de03bc2a9f623fcc283d5a107726a138fdd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
/*
 * Mesa 3-D graphics library
 * Version:  7.0.3
 *
 * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include "main/glheader.h"
#include "main/colormac.h"
#include "main/context.h"
#include "main/texstate.h"
#include "shader/prog_instruction.h"

#include "s_fragprog.h"
#include "s_span.h"


/**
 * Fetch a texel with given lod.
 * Called via machine->FetchTexelLod()
 */
static void
fetch_texel_lod( GLcontext *ctx, const GLfloat texcoord[4], GLfloat lambda,
                 GLuint unit, GLfloat color[4] )
{
   GLchan rgba[4];
   SWcontext *swrast = SWRAST_CONTEXT(ctx);
   const struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;

   if (texObj)
      lambda = CLAMP(lambda, texObj->MinLod, texObj->MaxLod);

   /* XXX use a float-valued TextureSample routine here!!! */
   swrast->TextureSample[unit](ctx, texObj, 1, (const GLfloat (*)[4]) texcoord,
                               &lambda, &rgba);
   color[0] = CHAN_TO_FLOAT(rgba[0]);
   color[1] = CHAN_TO_FLOAT(rgba[1]);
   color[2] = CHAN_TO_FLOAT(rgba[2]);
   color[3] = CHAN_TO_FLOAT(rgba[3]);
}


/**
 * Fetch a texel with the given partial derivatives to compute a level
 * of detail in the mipmap.
 * Called via machine->FetchTexelDeriv()
 */
static void
fetch_texel_deriv( GLcontext *ctx, const GLfloat texcoord[4],
                   const GLfloat texdx[4], const GLfloat texdy[4],
                   GLfloat lodBias, GLuint unit, GLfloat color[4] )
{
   SWcontext *swrast = SWRAST_CONTEXT(ctx);
   const struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
   GLfloat lambda;
   GLchan rgba[4];

   if (texObj) {
      const struct gl_texture_image *texImg = texObj->Image[0][texObj->BaseLevel];
      const GLfloat texW = (GLfloat) texImg->WidthScale;
      const GLfloat texH = (GLfloat) texImg->HeightScale;

      lambda = _swrast_compute_lambda(texdx[0], texdy[0], /* ds/dx, ds/dy */
                                      texdx[1], texdy[1], /* dt/dx, dt/dy */
                                      texdx[3], texdy[2], /* dq/dx, dq/dy */
                                      texW, texH,
                                      texcoord[0], texcoord[1], texcoord[3],
                                      1.0F / texcoord[3]) + lodBias;

      lambda = CLAMP(lambda, texObj->MinLod, texObj->MaxLod);
   }

   swrast->TextureSample[unit](ctx, texObj, 1, (const GLfloat (*)[4]) texcoord,
                               &lambda, &rgba);
   color[0] = CHAN_TO_FLOAT(rgba[0]);
   color[1] = CHAN_TO_FLOAT(rgba[1]);
   color[2] = CHAN_TO_FLOAT(rgba[2]);
   color[3] = CHAN_TO_FLOAT(rgba[3]);
}


/**
 * Initialize the virtual fragment program machine state prior to running
 * fragment program on a fragment.  This involves initializing the input
 * registers, condition codes, etc.
 * \param machine  the virtual machine state to init
 * \param program  the fragment program we're about to run
 * \param span  the span of pixels we'll operate on
 * \param col  which element (column) of the span we'll operate on
 */
static void
init_machine(GLcontext *ctx, struct gl_program_machine *machine,
             const struct gl_fragment_program *program,
             const SWspan *span, GLuint col)
{
   if (program->Base.Target == GL_FRAGMENT_PROGRAM_NV) {
      /* Clear temporary registers (undefined for ARB_f_p) */
      _mesa_bzero(machine->Temporaries,
                  MAX_PROGRAM_TEMPS * 4 * sizeof(GLfloat));
   }

   /* Setup pointer to input attributes */
   machine->Attribs = span->array->attribs;

   machine->DerivX = (GLfloat (*)[4]) span->attrStepX;
   machine->DerivY = (GLfloat (*)[4]) span->attrStepY;
   machine->NumDeriv = FRAG_ATTRIB_MAX;

   machine->Samplers = program->Base.SamplerUnits;

   /* if running a GLSL program (not ARB_fragment_program) */
   if (ctx->Shader.CurrentProgram) {
      /* Store front/back facing value in register FOGC.Y */
      machine->Attribs[FRAG_ATTRIB_FOGC][col][1] = 1.0 - span->facing;
   }

   machine->CurElement = col;

   /* init condition codes */
   machine->CondCodes[0] = COND_EQ;
   machine->CondCodes[1] = COND_EQ;
   machine->CondCodes[2] = COND_EQ;
   machine->CondCodes[3] = COND_EQ;

   /* init call stack */
   machine->StackDepth = 0;

   machine->FetchTexelLod = fetch_texel_lod;
   machine->FetchTexelDeriv = fetch_texel_deriv;
}


/**
 * Run fragment program on the pixels in span from 'start' to 'end' - 1.
 */
static void
run_program(GLcontext *ctx, SWspan *span, GLuint start, GLuint end)
{
   SWcontext *swrast = SWRAST_CONTEXT(ctx);
   const struct gl_fragment_program *program = ctx->FragmentProgram._Current;
   const GLbitfield outputsWritten = program->Base.OutputsWritten;
   struct gl_program_machine *machine = &swrast->FragProgMachine;
   GLuint i;

   for (i = start; i < end; i++) {
      if (span->array->mask[i]) {
         init_machine(ctx, machine, program, span, i);

         if (_mesa_execute_program(ctx, &program->Base, machine)) {

            /* Store result color */
            if (outputsWritten & (1 << FRAG_RESULT_COLR)) {
               COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0][i],
                       machine->Outputs[FRAG_RESULT_COLR]);
            }
            else {
               /* Multiple drawbuffers / render targets
                * Note that colors beyond 0 and 1 will overwrite other
                * attributes, such as FOGC, TEX0, TEX1, etc.  That's OK.
                */
               GLuint buf;
               for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
                  if (outputsWritten & (1 << (FRAG_RESULT_DATA0 + buf))) {
                     COPY_4V(span->array->attribs[FRAG_ATTRIB_COL0 + buf][i],
                             machine->Outputs[FRAG_RESULT_DATA0 + buf]);
                  }
               }
            }

            /* Store result depth/z */
            if (outputsWritten & (1 << FRAG_RESULT_DEPR)) {
               const GLfloat depth = machine->Outputs[FRAG_RESULT_DEPR][2];
               if (depth <= 0.0)
                  span->array->z[i] = 0;
               else if (depth >= 1.0)
                  span->array->z[i] = ctx->DrawBuffer->_DepthMax;
               else
                  span->array->z[i] = IROUND(depth * ctx->DrawBuffer->_DepthMaxF);
            }
         }
         else {
            /* killed fragment */
            span->array->mask[i] = GL_FALSE;
            span->writeAll = GL_FALSE;
         }
      }
   }
}


/**
 * Execute the current fragment program for all the fragments
 * in the given span.
 */
void
_swrast_exec_fragment_program( GLcontext *ctx, SWspan *span )
{
   const struct gl_fragment_program *program = ctx->FragmentProgram._Current;

   /* incoming colors should be floats */
   if (program->Base.InputsRead & FRAG_BIT_COL0) {
      ASSERT(span->array->ChanType == GL_FLOAT);
   }

   ctx->_CurrentProgram = GL_FRAGMENT_PROGRAM_ARB; /* or NV, doesn't matter */

   run_program(ctx, span, 0, span->end);

   if (program->Base.OutputsWritten & (1 << FRAG_RESULT_COLR)) {
      span->interpMask &= ~SPAN_RGBA;
      span->arrayMask |= SPAN_RGBA;
   }

   if (program->Base.OutputsWritten & (1 << FRAG_RESULT_DEPR)) {
      span->interpMask &= ~SPAN_Z;
      span->arrayMask |= SPAN_Z;
   }

   ctx->_CurrentProgram = 0;
}