src/mesa/drivers/dri/i965/gen6_multisample_state.c

   1 /*
   2  * Copyright © 2012 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #include "intel_batchbuffer.h"
  25
  26 #include "brw_context.h"
  27 #include "brw_defines.h"
  28 #include "brw_multisample_state.h"
  29
  30 void
  31 gen6_get_sample_position(struct gl_context *ctx,
  32                          struct gl_framebuffer *fb,
  33                          GLuint index, GLfloat *result)
  34 {
  35    switch (fb->Visual.samples) {
  36    case 1:
  37       result[0] = result[1] = 0.5f;
  38       break;
  39    case 4: {
  40       uint8_t val = (uint8_t)(brw_multisample_positions_4x[0] >> (8*index));
  41       result[0] = ((val >> 4) & 0xf) / 16.0f;
  42       result[1] = (val & 0xf) / 16.0f;
  43       break;
  44    }
  45    case 8: {
  46       uint8_t val = (uint8_t)(brw_multisample_positions_8x[index>>2] >> (8*(index & 3)));
  47       result[0] = ((val >> 4) & 0xf) / 16.0f;
  48       result[1] = (val & 0xf) / 16.0f;
  49       break;
  50    }
  51    default:
  52       assert(!"Not implemented");
  53    }
  54 }
  55
  56 /**
  57  * 3DSTATE_MULTISAMPLE
  58  */
  59 void
  60 gen6_emit_3dstate_multisample(struct brw_context *brw,
  61                               unsigned num_samples)
  62 {
  63    uint32_t number_of_multisamples = 0;
  64    uint32_t sample_positions_3210 = 0;
  65    uint32_t sample_positions_7654 = 0;
  66
  67    assert(brw->gen < 8);
  68
  69    switch (num_samples) {
  70    case 0:
  71    case 1:
  72       number_of_multisamples = MS_NUMSAMPLES_1;
  73       break;
  74    case 4:
  75       number_of_multisamples = MS_NUMSAMPLES_4;
  76       sample_positions_3210 = brw_multisample_positions_4x[0];
  77       break;
  78    case 8:
  79       number_of_multisamples = MS_NUMSAMPLES_8;
  80       sample_positions_3210 = brw_multisample_positions_8x[0];
  81       sample_positions_7654 = brw_multisample_positions_8x[1];
  82       break;
  83    default:
  84       assert(!"Unrecognized num_samples in gen6_emit_3dstate_multisample");
  85       break;
  86    }
  87
  88    /* 3DSTATE_MULTISAMPLE is nonpipelined. */
  89    intel_emit_post_sync_nonzero_flush(brw);
  90
  91    int len = brw->gen >= 7 ? 4 : 3;
  92    BEGIN_BATCH(len);
  93    OUT_BATCH(_3DSTATE_MULTISAMPLE << 16 | (len - 2));
  94    OUT_BATCH(MS_PIXEL_LOCATION_CENTER | number_of_multisamples);
  95    OUT_BATCH(sample_positions_3210);
  96    if (brw->gen >= 7)
  97       OUT_BATCH(sample_positions_7654);
  98    ADVANCE_BATCH();
  99 }
 100
 101
 102 unsigned
 103 gen6_determine_sample_mask(struct brw_context *brw)
 104 {
 105    struct gl_context *ctx = &brw->ctx;
 106    float coverage = 1.0;
 107    float coverage_invert = false;
 108    unsigned sample_mask = ~0u;
 109
 110    unsigned num_samples = ctx->DrawBuffer->Visual.samples;
 111
 112    if (ctx->Multisample._Enabled) {
 113       if (ctx->Multisample.SampleCoverage) {
 114          coverage = ctx->Multisample.SampleCoverageValue;
 115          coverage_invert = ctx->Multisample.SampleCoverageInvert;
 116       }
 117       if (ctx->Multisample.SampleMask) {
 118          sample_mask = ctx->Multisample.SampleMaskValue;
 119       }
 120    }
 121
 122    if (num_samples > 1) {
 123       int coverage_int = (int) (num_samples * coverage + 0.5);
 124       uint32_t coverage_bits = (1 << coverage_int) - 1;
 125       if (coverage_invert)
 126          coverage_bits ^= (1 << num_samples) - 1;
 127       return coverage_bits & sample_mask;
 128    } else {
 129       return 1;
 130    }
 131 }
 132
 133
 134 /**
 135  * 3DSTATE_SAMPLE_MASK
 136  */
 137 void
 138 gen6_emit_3dstate_sample_mask(struct brw_context *brw, unsigned mask)
 139 {
 140    BEGIN_BATCH(2);
 141    OUT_BATCH(_3DSTATE_SAMPLE_MASK << 16 | (2 - 2));
 142    OUT_BATCH(mask);
 143    ADVANCE_BATCH();
 144 }
 145
 146
 147 static void upload_multisample_state(struct brw_context *brw)
 148 {
 149    struct gl_context *ctx = &brw->ctx;
 150
 151    /* _NEW_BUFFERS, _NEW_MULTISAMPLE */
 152    unsigned num_samples = ctx->DrawBuffer->Visual.samples;
 153
 154    gen6_emit_3dstate_multisample(brw, num_samples);
 155    gen6_emit_3dstate_sample_mask(brw, gen6_determine_sample_mask(brw));
 156 }
 157
 158
 159 const struct brw_tracked_state gen6_multisample_state = {
 160    .dirty = {
 161       .mesa = _NEW_BUFFERS |
 162               _NEW_MULTISAMPLE,
 163       .brw = BRW_NEW_CONTEXT,
 164       .cache = 0
 165    },
 166    .emit = upload_multisample_state
 167 };