sp_quad_fs.c revision e8830f5a4009c3784836edb441319a62c7beef36 
1/**************************************************************************
2 *
3 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
4 * All Rights Reserved.
5 * Copyright 2008 VMware, Inc.  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
9 * "Software"), to deal in the Software without restriction, including
10 * without limitation the rights to use, copy, modify, merge, publish,
11 * distribute, sub license, and/or sell copies of the Software, and to
12 * permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the
16 * next paragraph) shall be included in all copies or substantial portions
17 * of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
20 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
22 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
23 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
24 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
25 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 *
27 **************************************************************************/
28
29/* Vertices are just an array of floats, with all the attributes
30 * packed.  We currently assume a layout like:
31 *
32 * attr[0][0..3] - window position
33 * attr[1..n][0..3] - remaining attributes.
34 *
35 * Attributes are assumed to be 4 floats wide but are packed so that
36 * all the enabled attributes run contiguously.
37 */
38
39#include "util/u_math.h"
40#include "util/u_memory.h"
41#include "pipe/p_defines.h"
42#include "pipe/p_shader_tokens.h"
43
44#include "sp_context.h"
45#include "sp_state.h"
46#include "sp_quad.h"
47#include "sp_quad_pipe.h"
48
49
50struct quad_shade_stage
51{
52   struct quad_stage stage;  /**< base class */
53
54   /* no other fields at this time */
55};
56
57
58/** cast wrapper */
59static INLINE struct quad_shade_stage *
60quad_shade_stage(struct quad_stage *qs)
61{
62   return (struct quad_shade_stage *) qs;
63}
64
65
66/**
67 * Execute fragment shader for the four fragments in the quad.
68 * \return TRUE if quad is alive, FALSE if all four pixels are killed
69 */
70static INLINE boolean
71shade_quad(struct quad_stage *qs, struct quad_header *quad)
72{
73   struct softpipe_context *softpipe = qs->softpipe;
74   struct tgsi_exec_machine *machine = softpipe->fs_machine;
75
76   /* run shader */
77   machine->flatshade_color = softpipe->rasterizer->flatshade ? TRUE : FALSE;
78   return softpipe->fs_variant->run( softpipe->fs_variant, machine, quad );
79}
80
81
82
83static void
84coverage_quad(struct quad_stage *qs, struct quad_header *quad)
85{
86   struct softpipe_context *softpipe = qs->softpipe;
87   uint cbuf;
88
89   /* loop over colorbuffer outputs */
90   for (cbuf = 0; cbuf < softpipe->framebuffer.nr_cbufs; cbuf++) {
91      float (*quadColor)[4] = quad->output.color[cbuf];
92      unsigned j;
93      for (j = 0; j < TGSI_QUAD_SIZE; j++) {
94         assert(quad->input.coverage[j] >= 0.0);
95         assert(quad->input.coverage[j] <= 1.0);
96         quadColor[3][j] *= quad->input.coverage[j];
97      }
98   }
99}
100
101
102/**
103 * Shade/write an array of quads
104 * Called via quad_stage::run()
105 */
106static void
107shade_quads(struct quad_stage *qs,
108            struct quad_header *quads[],
109            unsigned nr)
110{
111   struct softpipe_context *softpipe = qs->softpipe;
112   struct tgsi_exec_machine *machine = softpipe->fs_machine;
113   unsigned i, nr_quads = 0;
114
115   tgsi_exec_set_constant_buffers(machine, PIPE_MAX_CONSTANT_BUFFERS,
116                         softpipe->mapped_constants[PIPE_SHADER_FRAGMENT],
117                         softpipe->const_buffer_size[PIPE_SHADER_FRAGMENT]);
118
119   machine->InterpCoefs = quads[0]->coef;
120
121   for (i = 0; i < nr; i++) {
122      /* Only omit this quad from the output list if all the fragments
123       * are killed _AND_ it's not the first quad in the list.
124       * The first quad is special in the (optimized) depth-testing code:
125       * the quads' Z coordinates are step-wise interpolated with respect
126       * to the first quad in the list.
127       * For multi-pass algorithms we need to produce exactly the same
128       * Z values in each pass.  If interpolation starts with different quads
129       * we can get different Z values for the same (x,y).
130       */
131      if (!shade_quad(qs, quads[i]) && i > 0)
132         continue; /* quad totally culled/killed */
133
134      if (/*do_coverage*/ 0)
135         coverage_quad( qs, quads[i] );
136
137      quads[nr_quads++] = quads[i];
138   }
139
140   if (nr_quads)
141      qs->next->run(qs->next, quads, nr_quads);
142}
143
144
145/**
146 * Per-primitive (or per-begin?) setup
147 */
148static void
149shade_begin(struct quad_stage *qs)
150{
151   qs->next->begin(qs->next);
152}
153
154
155static void
156shade_destroy(struct quad_stage *qs)
157{
158   FREE( qs );
159}
160
161
162struct quad_stage *
163sp_quad_shade_stage( struct softpipe_context *softpipe )
164{
165   struct quad_shade_stage *qss = CALLOC_STRUCT(quad_shade_stage);
166   if (!qss)
167      goto fail;
168
169   qss->stage.softpipe = softpipe;
170   qss->stage.begin = shade_begin;
171   qss->stage.run = shade_quads;
172   qss->stage.destroy = shade_destroy;
173
174   return &qss->stage;
175
176fail:
177   FREE(qss);
178   return NULL;
179}
180