1/*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25#include "main/glheader.h"
26#include "main/macros.h"
27#include "main/samplerobj.h"
28#include "main/teximage.h"
29#include "program/prog_instruction.h"
30
31#include "s_context.h"
32#include "s_fragprog.h"
33#include "s_span.h"
34
35/**
36 * \brief Should swrast use a fragment program?
37 *
38 * \return true if the current fragment program exists and is not the fixed
39 *         function fragment program
40 */
41GLboolean
42_swrast_use_fragment_program(struct gl_context *ctx)
43{
44   struct gl_program *fp = ctx->FragmentProgram._Current;
45   return fp && !(fp == ctx->FragmentProgram._TexEnvProgram
46                  && fp->arb.NumInstructions == 0);
47}
48
49/**
50 * Apply texture object's swizzle (X/Y/Z/W/0/1) to incoming 'texel'
51 * and return results in 'colorOut'.
52 */
53static inline void
54swizzle_texel(const GLfloat texel[4], GLfloat colorOut[4], GLuint swizzle)
55{
56   if (swizzle == SWIZZLE_NOOP) {
57      COPY_4V(colorOut, texel);
58   }
59   else {
60      GLfloat vector[6];
61      vector[SWIZZLE_X] = texel[0];
62      vector[SWIZZLE_Y] = texel[1];
63      vector[SWIZZLE_Z] = texel[2];
64      vector[SWIZZLE_W] = texel[3];
65      vector[SWIZZLE_ZERO] = 0.0F;
66      vector[SWIZZLE_ONE] = 1.0F;
67      colorOut[0] = vector[GET_SWZ(swizzle, 0)];
68      colorOut[1] = vector[GET_SWZ(swizzle, 1)];
69      colorOut[2] = vector[GET_SWZ(swizzle, 2)];
70      colorOut[3] = vector[GET_SWZ(swizzle, 3)];
71   }
72}
73
74
75/**
76 * Fetch a texel with given lod.
77 * Called via machine->FetchTexelLod()
78 */
79static void
80fetch_texel_lod( struct gl_context *ctx, const GLfloat texcoord[4], GLfloat lambda,
81                 GLuint unit, GLfloat color[4] )
82{
83   const struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
84
85   if (texObj) {
86      SWcontext *swrast = SWRAST_CONTEXT(ctx);
87      GLfloat rgba[4];
88      const struct gl_sampler_object *samp = _mesa_get_samplerobj(ctx, unit);
89
90      lambda = CLAMP(lambda, samp->MinLod, samp->MaxLod);
91
92      swrast->TextureSample[unit](ctx, samp, ctx->Texture.Unit[unit]._Current,
93                                  1, (const GLfloat (*)[4]) texcoord,
94                                  &lambda, &rgba);
95      swizzle_texel(rgba, color, texObj->_Swizzle);
96   }
97   else {
98      ASSIGN_4V(color, 0.0F, 0.0F, 0.0F, 1.0F);
99   }
100}
101
102
103/**
104 * Fetch a texel with the given partial derivatives to compute a level
105 * of detail in the mipmap.
106 * Called via machine->FetchTexelDeriv()
107 * \param lodBias  the lod bias which may be specified by a TXB instruction,
108 *                 otherwise zero.
109 */
110static void
111fetch_texel_deriv( struct gl_context *ctx, const GLfloat texcoord[4],
112                   const GLfloat texdx[4], const GLfloat texdy[4],
113                   GLfloat lodBias, GLuint unit, GLfloat color[4] )
114{
115   SWcontext *swrast = SWRAST_CONTEXT(ctx);
116   const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
117   const struct gl_texture_object *texObj = texUnit->_Current;
118
119   if (texObj) {
120      const struct gl_texture_image *texImg = _mesa_base_tex_image(texObj);
121      const struct swrast_texture_image *swImg =
122         swrast_texture_image_const(texImg);
123      const struct gl_sampler_object *samp = _mesa_get_samplerobj(ctx, unit);
124      const GLfloat texW = (GLfloat) swImg->WidthScale;
125      const GLfloat texH = (GLfloat) swImg->HeightScale;
126      GLfloat lambda;
127      GLfloat rgba[4];
128
129      lambda = _swrast_compute_lambda(texdx[0], texdy[0], /* ds/dx, ds/dy */
130                                      texdx[1], texdy[1], /* dt/dx, dt/dy */
131                                      texdx[3], texdy[3], /* dq/dx, dq/dy */
132                                      texW, texH,
133                                      texcoord[0], texcoord[1], texcoord[3],
134                                      1.0F / texcoord[3]);
135
136      lambda += lodBias + texUnit->LodBias + samp->LodBias;
137
138      lambda = CLAMP(lambda, samp->MinLod, samp->MaxLod);
139
140      swrast->TextureSample[unit](ctx, samp, ctx->Texture.Unit[unit]._Current,
141                                  1, (const GLfloat (*)[4]) texcoord,
142                                  &lambda, &rgba);
143      swizzle_texel(rgba, color, texObj->_Swizzle);
144   }
145   else {
146      ASSIGN_4V(color, 0.0F, 0.0F, 0.0F, 1.0F);
147   }
148}
149
150
151/**
152 * Initialize the virtual fragment program machine state prior to running
153 * fragment program on a fragment.  This involves initializing the input
154 * registers, condition codes, etc.
155 * \param machine  the virtual machine state to init
156 * \param program  the fragment program we're about to run
157 * \param span  the span of pixels we'll operate on
158 * \param col  which element (column) of the span we'll operate on
159 */
160static void
161init_machine(struct gl_context *ctx, struct gl_program_machine *machine,
162             const struct gl_program *program, const SWspan *span, GLuint col)
163{
164   GLfloat *wpos = span->array->attribs[VARYING_SLOT_POS][col];
165
166   /* ARB_fragment_coord_conventions */
167   if (program->OriginUpperLeft)
168      wpos[1] = ctx->DrawBuffer->Height - 1 - wpos[1];
169   if (!program->PixelCenterInteger) {
170      wpos[0] += 0.5F;
171      wpos[1] += 0.5F;
172   }
173
174   /* Setup pointer to input attributes */
175   machine->Attribs = span->array->attribs;
176
177   machine->DerivX = (GLfloat (*)[4]) span->attrStepX;
178   machine->DerivY = (GLfloat (*)[4]) span->attrStepY;
179   machine->NumDeriv = VARYING_SLOT_MAX;
180
181   machine->Samplers = program->SamplerUnits;
182
183   /* if running a GLSL program (not ARB_fragment_program) */
184   if (ctx->_Shader->CurrentProgram[MESA_SHADER_FRAGMENT]) {
185      /* Store front/back facing value */
186      machine->Attribs[VARYING_SLOT_FACE][col][0] = 1.0F - span->facing;
187   }
188
189   machine->CurElement = col;
190
191   /* init call stack */
192   machine->StackDepth = 0;
193
194   machine->FetchTexelLod = fetch_texel_lod;
195   machine->FetchTexelDeriv = fetch_texel_deriv;
196}
197
198
199/**
200 * Run fragment program on the pixels in span from 'start' to 'end' - 1.
201 */
202static void
203run_program(struct gl_context *ctx, SWspan *span, GLuint start, GLuint end)
204{
205   SWcontext *swrast = SWRAST_CONTEXT(ctx);
206   const struct gl_program *program = ctx->FragmentProgram._Current;
207   const GLbitfield64 outputsWritten = program->info.outputs_written;
208   struct gl_program_machine *machine = &swrast->FragProgMachine;
209   GLuint i;
210
211   for (i = start; i < end; i++) {
212      if (span->array->mask[i]) {
213         init_machine(ctx, machine, program, span, i);
214
215         if (_mesa_execute_program(ctx, program, machine)) {
216
217            /* Store result color */
218	    if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
219               COPY_4V(span->array->attribs[VARYING_SLOT_COL0][i],
220                       machine->Outputs[FRAG_RESULT_COLOR]);
221            }
222            else {
223               /* Multiple drawbuffers / render targets
224                * Note that colors beyond 0 and 1 will overwrite other
225                * attributes, such as FOGC, TEX0, TEX1, etc.  That's OK.
226                */
227               GLuint buf;
228               for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
229                  if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DATA0 + buf)) {
230                     COPY_4V(span->array->attribs[VARYING_SLOT_COL0 + buf][i],
231                             machine->Outputs[FRAG_RESULT_DATA0 + buf]);
232                  }
233               }
234            }
235
236            /* Store result depth/z */
237            if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
238               const GLfloat depth = machine->Outputs[FRAG_RESULT_DEPTH][2];
239               if (depth <= 0.0F)
240                  span->array->z[i] = 0;
241               else if (depth >= 1.0F)
242                  span->array->z[i] = ctx->DrawBuffer->_DepthMax;
243               else
244                  span->array->z[i] =
245                     (GLuint) (depth * ctx->DrawBuffer->_DepthMaxF + 0.5F);
246            }
247         }
248         else {
249            /* killed fragment */
250            span->array->mask[i] = GL_FALSE;
251            span->writeAll = GL_FALSE;
252         }
253      }
254   }
255}
256
257
258/**
259 * Execute the current fragment program for all the fragments
260 * in the given span.
261 */
262void
263_swrast_exec_fragment_program( struct gl_context *ctx, SWspan *span )
264{
265   const struct gl_program *program = ctx->FragmentProgram._Current;
266
267   /* incoming colors should be floats */
268   if (program->info.inputs_read & VARYING_BIT_COL0) {
269      assert(span->array->ChanType == GL_FLOAT);
270   }
271
272   run_program(ctx, span, 0, span->end);
273
274   if (program->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
275      span->interpMask &= ~SPAN_RGBA;
276      span->arrayMask |= SPAN_RGBA;
277   }
278
279   if (program->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
280      span->interpMask &= ~SPAN_Z;
281      span->arrayMask |= SPAN_Z;
282   }
283}
284
285