src/gallium/drivers/softpipe/sp_quad_fs.c

   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
  50 struct 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 */
  59 static INLINE struct quad_shade_stage *
  60 quad_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  */
  70 static INLINE boolean
  71 shade_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
  83 static void
  84 coverage_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  */
 106 static void
 107 shade_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  */
 148 static void
 149 shade_begin(struct quad_stage *qs)
 150 {
 151    struct softpipe_context *softpipe = qs->softpipe;
 152
 153    softpipe->fs_variant->prepare( softpipe->fs_variant,
 154                                   softpipe->fs_machine,
 155                                   (struct tgsi_sampler **)
 156                                   softpipe->tgsi.samplers_list[PIPE_SHADER_FRAGMENT] );
 157
 158    qs->next->begin(qs->next);
 159 }
 160
 161
 162 static void
 163 shade_destroy(struct quad_stage *qs)
 164 {
 165    FREE( qs );
 166 }
 167
 168
 169 struct quad_stage *
 170 sp_quad_shade_stage( struct softpipe_context *softpipe )
 171 {
 172    struct quad_shade_stage *qss = CALLOC_STRUCT(quad_shade_stage);
 173    if (!qss)
 174       goto fail;
 175
 176    qss->stage.softpipe = softpipe;
 177    qss->stage.begin = shade_begin;
 178    qss->stage.run = shade_quads;
 179    qss->stage.destroy = shade_destroy;
 180
 181    return &qss->stage;
 182
 183 fail:
 184    FREE(qss);
 185    return NULL;
 186 }