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

   1 /*
   2  * Copyright 2003 VMware, Inc.
   3  * Copyright 2009, 2012 Intel Corporation.
   4  * 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
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27 #include "main/glheader.h"
  28 #include "main/mtypes.h"
  29 #include "main/condrender.h"
  30 #include "swrast/swrast.h"
  31 #include "drivers/common/meta.h"
  32
  33 #include "intel_batchbuffer.h"
  34 #include "intel_blit.h"
  35 #include "intel_fbo.h"
  36 #include "intel_mipmap_tree.h"
  37
  38 #include "brw_context.h"
  39 #include "brw_blorp.h"
  40
  41 #define FILE_DEBUG_FLAG DEBUG_BLIT
  42
  43 static const char *buffer_names[] = {
  44    [BUFFER_FRONT_LEFT] = "front",
  45    [BUFFER_BACK_LEFT] = "back",
  46    [BUFFER_FRONT_RIGHT] = "front right",
  47    [BUFFER_BACK_RIGHT] = "back right",
  48    [BUFFER_DEPTH] = "depth",
  49    [BUFFER_STENCIL] = "stencil",
  50    [BUFFER_ACCUM] = "accum",
  51    [BUFFER_AUX0] = "aux0",
  52    [BUFFER_COLOR0] = "color0",
  53    [BUFFER_COLOR1] = "color1",
  54    [BUFFER_COLOR2] = "color2",
  55    [BUFFER_COLOR3] = "color3",
  56    [BUFFER_COLOR4] = "color4",
  57    [BUFFER_COLOR5] = "color5",
  58    [BUFFER_COLOR6] = "color6",
  59    [BUFFER_COLOR7] = "color7",
  60 };
  61
  62 static void
  63 debug_mask(const char *name, GLbitfield mask)
  64 {
  65    GLuint i;
  66
  67    if (unlikely(INTEL_DEBUG & DEBUG_BLIT)) {
  68       DBG("%s clear:", name);
  69       for (i = 0; i < BUFFER_COUNT; i++) {
  70          if (mask & (1 << i))
  71             DBG(" %s", buffer_names[i]);
  72       }
  73       DBG("\n");
  74    }
  75 }
  76
  77 /**
  78  * Returns true if the scissor is a noop (cuts out nothing).
  79  */
  80 static bool
  81 noop_scissor(struct gl_context *ctx, struct gl_framebuffer *fb)
  82 {
  83    return ctx->Scissor.ScissorArray[0].X <= 0 &&
  84           ctx->Scissor.ScissorArray[0].Y <= 0 &&
  85           ctx->Scissor.ScissorArray[0].Width >= fb->Width &&
  86           ctx->Scissor.ScissorArray[0].Height >= fb->Height;
  87 }
  88
  89 /**
  90  * Implements fast depth clears on gen6+.
  91  *
  92  * Fast clears basically work by setting a flag in each of the subspans
  93  * represented in the HiZ buffer that says "When you need the depth values for
  94  * this subspan, it's the hardware's current clear value."  Then later rendering
  95  * can just use the static clear value instead of referencing memory.
  96  *
  97  * The tricky part of the implementation is that you have to have the clear
  98  * value that was used on the depth buffer in place for all further rendering,
  99  * at least until a resolve to the real depth buffer happens.
 100  */
 101 static bool
 102 brw_fast_clear_depth(struct gl_context *ctx)
 103 {
 104    struct brw_context *brw = brw_context(ctx);
 105    struct gl_framebuffer *fb = ctx->DrawBuffer;
 106    struct intel_renderbuffer *depth_irb =
 107       intel_get_renderbuffer(fb, BUFFER_DEPTH);
 108    struct intel_mipmap_tree *mt = depth_irb->mt;
 109    struct gl_renderbuffer_attachment *depth_att = &fb->Attachment[BUFFER_DEPTH];
 110
 111    if (brw->gen < 6)
 112       return false;
 113
 114    if (!intel_renderbuffer_has_hiz(depth_irb))
 115       return false;
 116
 117    /* We only handle full buffer clears -- otherwise you'd have to track whether
 118     * a previous clear had happened at a different clear value and resolve it
 119     * first.
 120     */
 121    if ((ctx->Scissor.EnableFlags & 1) && !noop_scissor(ctx, fb)) {
 122       perf_debug("Failed to fast clear %dx%d depth because of scissors.  "
 123                  "Possible 5%% performance win if avoided.\n",
 124                  mt->logical_width0, mt->logical_height0);
 125       return false;
 126    }
 127
 128    uint32_t depth_clear_value;
 129    switch (mt->format) {
 130    case MESA_FORMAT_Z32_FLOAT_S8X24_UINT:
 131    case MESA_FORMAT_Z24_UNORM_S8_UINT:
 132       /* From the Sandy Bridge PRM, volume 2 part 1, page 314:
 133        *
 134        *     "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
 135        *      enabled (the legacy method of clearing must be performed):
 136        *
 137        *      - If the depth buffer format is D32_FLOAT_S8X24_UINT or
 138        *        D24_UNORM_S8_UINT.
 139        */
 140       return false;
 141
 142    case MESA_FORMAT_Z_FLOAT32:
 143       depth_clear_value = float_as_int(ctx->Depth.Clear);
 144       break;
 145
 146    case MESA_FORMAT_Z_UNORM16:
 147       /* From the Sandy Bridge PRM, volume 2 part 1, page 314:
 148        *
 149        *     "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
 150        *      enabled (the legacy method of clearing must be performed):
 151        *
 152        *      - DevSNB{W/A}]: When depth buffer format is D16_UNORM and the
 153        *        width of the map (LOD0) is not multiple of 16, fast clear
 154        *        optimization must be disabled.
 155        */
 156       if (brw->gen == 6 &&
 157           (minify(mt->physical_width0,
 158                   depth_irb->mt_level - mt->first_level) % 16) != 0)
 159          return false;
 160       /* FALLTHROUGH */
 161
 162    default:
 163       if (brw->gen >= 8)
 164          depth_clear_value = float_as_int(ctx->Depth.Clear);
 165       else
 166          depth_clear_value = fb->_DepthMax * ctx->Depth.Clear;
 167       break;
 168    }
 169
 170    /* If we're clearing to a new clear value, then we need to resolve any clear
 171     * flags out of the HiZ buffer into the real depth buffer.
 172     */
 173    if (mt->depth_clear_value != depth_clear_value) {
 174       intel_miptree_all_slices_resolve_depth(brw, mt);
 175       mt->depth_clear_value = depth_clear_value;
 176    }
 177
 178    /* From the Sandy Bridge PRM, volume 2 part 1, page 313:
 179     *
 180     *     "If other rendering operations have preceded this clear, a
 181     *      PIPE_CONTROL with write cache flush enabled and Z-inhibit disabled
 182     *      must be issued before the rectangle primitive used for the depth
 183     *      buffer clear operation.
 184     */
 185    brw_emit_mi_flush(brw);
 186
 187    if (fb->MaxNumLayers > 0) {
 188       for (unsigned layer = 0; layer < depth_irb->layer_count; layer++) {
 189          intel_hiz_exec(brw, mt, depth_irb->mt_level,
 190                         depth_irb->mt_layer + layer,
 191                         GEN6_HIZ_OP_DEPTH_CLEAR);
 192       }
 193    } else {
 194       intel_hiz_exec(brw, mt, depth_irb->mt_level, depth_irb->mt_layer,
 195                      GEN6_HIZ_OP_DEPTH_CLEAR);
 196    }
 197
 198    if (brw->gen == 6) {
 199       /* From the Sandy Bridge PRM, volume 2 part 1, page 314:
 200        *
 201        *     "DevSNB, DevSNB-B{W/A}]: Depth buffer clear pass must be followed
 202        *      by a PIPE_CONTROL command with DEPTH_STALL bit set and Then
 203        *      followed by Depth FLUSH'
 204       */
 205       brw_emit_mi_flush(brw);
 206    }
 207
 208    /* Now, the HiZ buffer contains data that needs to be resolved to the depth
 209     * buffer.
 210     */
 211    intel_renderbuffer_att_set_needs_depth_resolve(depth_att);
 212
 213    return true;
 214 }
 215
 216 /**
 217  * Called by ctx->Driver.Clear.
 218  */
 219 static void
 220 brw_clear(struct gl_context *ctx, GLbitfield mask)
 221 {
 222    struct brw_context *brw = brw_context(ctx);
 223    struct gl_framebuffer *fb = ctx->DrawBuffer;
 224    bool partial_clear = ctx->Scissor.EnableFlags && !noop_scissor(ctx, fb);
 225
 226    if (!_mesa_check_conditional_render(ctx))
 227       return;
 228
 229    if (mask & (BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT)) {
 230       brw->front_buffer_dirty = true;
 231    }
 232
 233    intel_prepare_render(brw);
 234    brw_workaround_depthstencil_alignment(brw, partial_clear ? 0 : mask);
 235
 236    if (mask & BUFFER_BIT_DEPTH) {
 237       if (brw_fast_clear_depth(ctx)) {
 238          DBG("fast clear: depth\n");
 239          mask &= ~BUFFER_BIT_DEPTH;
 240       }
 241    }
 242
 243    /* Clear color buffers with fast clear or at least rep16 writes. */
 244    if (brw->gen >= 6 && brw->gen < 9 && (mask & BUFFER_BITS_COLOR)) {
 245       if (brw_meta_fast_clear(brw, fb, mask, partial_clear)) {
 246          debug_mask("blorp color", mask & BUFFER_BITS_COLOR);
 247          mask &= ~BUFFER_BITS_COLOR;
 248       }
 249    }
 250
 251    GLbitfield tri_mask = mask & (BUFFER_BITS_COLOR |
 252                                  BUFFER_BIT_STENCIL |
 253                                  BUFFER_BIT_DEPTH);
 254
 255    if (tri_mask) {
 256       debug_mask("tri", tri_mask);
 257       mask &= ~tri_mask;
 258
 259       if (ctx->API == API_OPENGLES) {
 260          _mesa_meta_Clear(&brw->ctx, tri_mask);
 261       } else {
 262          _mesa_meta_glsl_Clear(&brw->ctx, tri_mask);
 263       }
 264    }
 265
 266    /* Any strange buffers get passed off to swrast */
 267    if (mask) {
 268       debug_mask("swrast", mask);
 269       _swrast_Clear(ctx, mask);
 270    }
 271 }
 272
 273
 274 void
 275 intelInitClearFuncs(struct dd_function_table *functions)
 276 {
 277    functions->Clear = brw_clear;
 278 }