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

   1 /**************************************************************************
   2  *
   3  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * Copyright 2009, 2012 Intel Corporation.
   5  * 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 #include "main/glheader.h"
  30 #include "main/mtypes.h"
  31 #include "main/condrender.h"
  32 #include "swrast/swrast.h"
  33 #include "drivers/common/meta.h"
  34
  35 #include "intel_batchbuffer.h"
  36 #include "intel_blit.h"
  37 #include "intel_fbo.h"
  38 #include "intel_mipmap_tree.h"
  39 #include "intel_regions.h"
  40
  41 #include "brw_context.h"
  42 #include "brw_blorp.h"
  43
  44 #define FILE_DEBUG_FLAG DEBUG_BLIT
  45
  46 static const char *buffer_names[] = {
  47    [BUFFER_FRONT_LEFT] = "front",
  48    [BUFFER_BACK_LEFT] = "back",
  49    [BUFFER_FRONT_RIGHT] = "front right",
  50    [BUFFER_BACK_RIGHT] = "back right",
  51    [BUFFER_DEPTH] = "depth",
  52    [BUFFER_STENCIL] = "stencil",
  53    [BUFFER_ACCUM] = "accum",
  54    [BUFFER_AUX0] = "aux0",
  55    [BUFFER_COLOR0] = "color0",
  56    [BUFFER_COLOR1] = "color1",
  57    [BUFFER_COLOR2] = "color2",
  58    [BUFFER_COLOR3] = "color3",
  59    [BUFFER_COLOR4] = "color4",
  60    [BUFFER_COLOR5] = "color5",
  61    [BUFFER_COLOR6] = "color6",
  62    [BUFFER_COLOR7] = "color7",
  63 };
  64
  65 static void
  66 debug_mask(const char *name, GLbitfield mask)
  67 {
  68    GLuint i;
  69
  70    if (unlikely(INTEL_DEBUG & DEBUG_BLIT)) {
  71       DBG("%s clear:", name);
  72       for (i = 0; i < BUFFER_COUNT; i++) {
  73          if (mask & (1 << i))
  74             DBG(" %s", buffer_names[i]);
  75       }
  76       DBG("\n");
  77    }
  78 }
  79
  80 /**
  81  * Returns true if the scissor is a noop (cuts out nothing).
  82  */
  83 static bool
  84 noop_scissor(struct gl_context *ctx, struct gl_framebuffer *fb)
  85 {
  86    return ctx->Scissor.X <= 0 &&
  87           ctx->Scissor.Y <= 0 &&
  88           ctx->Scissor.Width >= fb->Width &&
  89           ctx->Scissor.Height >= fb->Height;
  90 }
  91
  92 /**
  93  * Implements fast depth clears on gen6+.
  94  *
  95  * Fast clears basically work by setting a flag in each of the subspans
  96  * represented in the HiZ buffer that says "When you need the depth values for
  97  * this subspan, it's the hardware's current clear value."  Then later rendering
  98  * can just use the static clear value instead of referencing memory.
  99  *
 100  * The tricky part of the implementation is that you have to have the clear
 101  * value that was used on the depth buffer in place for all further rendering,
 102  * at least until a resolve to the real depth buffer happens.
 103  */
 104 static bool
 105 brw_fast_clear_depth(struct gl_context *ctx)
 106 {
 107    struct brw_context *brw = brw_context(ctx);
 108    struct intel_context *intel = intel_context(ctx);
 109    struct gl_framebuffer *fb = ctx->DrawBuffer;
 110    struct intel_renderbuffer *depth_irb =
 111       intel_get_renderbuffer(fb, BUFFER_DEPTH);
 112    struct intel_mipmap_tree *mt = depth_irb->mt;
 113
 114    if (intel->gen < 6)
 115       return false;
 116
 117    if (!intel_renderbuffer_has_hiz(depth_irb))
 118       return false;
 119
 120    /* We only handle full buffer clears -- otherwise you'd have to track whether
 121     * a previous clear had happened at a different clear value and resolve it
 122     * first.
 123     */
 124    if (ctx->Scissor.Enabled && !noop_scissor(ctx, fb)) {
 125       perf_debug("Failed to fast clear depth due to scissor being enabled.  "
 126                  "Possible 5%% performance win if avoided.\n");
 127       return false;
 128    }
 129
 130    uint32_t depth_clear_value;
 131    switch (mt->format) {
 132    case MESA_FORMAT_Z32_FLOAT_X24S8:
 133    case MESA_FORMAT_S8_Z24:
 134       /* From the Sandy Bridge PRM, volume 2 part 1, page 314:
 135        *
 136        *     "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
 137        *      enabled (the legacy method of clearing must be performed):
 138        *
 139        *      - If the depth buffer format is D32_FLOAT_S8X24_UINT or
 140        *        D24_UNORM_S8_UINT.
 141        */
 142       return false;
 143
 144    case MESA_FORMAT_Z32_FLOAT:
 145       depth_clear_value = float_as_int(ctx->Depth.Clear);
 146       break;
 147
 148    case MESA_FORMAT_Z16:
 149       /* From the Sandy Bridge PRM, volume 2 part 1, page 314:
 150        *
 151        *     "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
 152        *      enabled (the legacy method of clearing must be performed):
 153        *
 154        *      - DevSNB{W/A}]: When depth buffer format is D16_UNORM and the
 155        *        width of the map (LOD0) is not multiple of 16, fast clear
 156        *        optimization must be disabled.
 157        */
 158       if (intel->gen == 6 && (mt->level[depth_irb->mt_level].width % 16) != 0)
 159          return false;
 160       /* FALLTHROUGH */
 161
 162    default:
 163       depth_clear_value = fb->_DepthMax * ctx->Depth.Clear;
 164       break;
 165    }
 166
 167    /* If we're clearing to a new clear value, then we need to resolve any clear
 168     * flags out of the HiZ buffer into the real depth buffer.
 169     */
 170    if (mt->depth_clear_value != depth_clear_value) {
 171       intel_miptree_all_slices_resolve_depth(brw, mt);
 172       mt->depth_clear_value = depth_clear_value;
 173    }
 174
 175    /* From the Sandy Bridge PRM, volume 2 part 1, page 313:
 176     *
 177     *     "If other rendering operations have preceded this clear, a
 178     *      PIPE_CONTROL with write cache flush enabled and Z-inhibit disabled
 179     *      must be issued before the rectangle primitive used for the depth
 180     *      buffer clear operation.
 181     */
 182    intel_batchbuffer_emit_mi_flush(brw);
 183
 184    intel_hiz_exec(brw, mt, depth_irb->mt_level, depth_irb->mt_layer,
 185                   GEN6_HIZ_OP_DEPTH_CLEAR);
 186
 187    if (intel->gen == 6) {
 188       /* From the Sandy Bridge PRM, volume 2 part 1, page 314:
 189        *
 190        *     "DevSNB, DevSNB-B{W/A}]: Depth buffer clear pass must be followed
 191        *      by a PIPE_CONTROL command with DEPTH_STALL bit set and Then
 192        *      followed by Depth FLUSH'
 193       */
 194       intel_batchbuffer_emit_mi_flush(brw);
 195    }
 196
 197    /* Now, the HiZ buffer contains data that needs to be resolved to the depth
 198     * buffer.
 199     */
 200    intel_renderbuffer_set_needs_depth_resolve(depth_irb);
 201
 202    return true;
 203 }
 204
 205 /**
 206  * Called by ctx->Driver.Clear.
 207  */
 208 static void
 209 brw_clear(struct gl_context *ctx, GLbitfield mask)
 210 {
 211    struct brw_context *brw = brw_context(ctx);
 212    struct intel_context *intel = &brw->intel;
 213    struct gl_framebuffer *fb = ctx->DrawBuffer;
 214    bool partial_clear = ctx->Scissor.Enabled && !noop_scissor(ctx, fb);
 215
 216    if (!_mesa_check_conditional_render(ctx))
 217       return;
 218
 219    if (mask & (BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT)) {
 220       intel->front_buffer_dirty = true;
 221    }
 222
 223    intel_prepare_render(brw);
 224    brw_workaround_depthstencil_alignment(brw, partial_clear ? 0 : mask);
 225
 226    if (mask & BUFFER_BIT_DEPTH) {
 227       if (brw_fast_clear_depth(ctx)) {
 228          DBG("fast clear: depth\n");
 229          mask &= ~BUFFER_BIT_DEPTH;
 230       }
 231    }
 232
 233    /* BLORP is currently only supported on Gen6+. */
 234    if (intel->gen >= 6) {
 235       if (mask & BUFFER_BITS_COLOR) {
 236          if (brw_blorp_clear_color(brw, fb, partial_clear)) {
 237             debug_mask("blorp color", mask & BUFFER_BITS_COLOR);
 238             mask &= ~BUFFER_BITS_COLOR;
 239          }
 240       }
 241    }
 242
 243    GLbitfield tri_mask = mask & (BUFFER_BITS_COLOR |
 244                                  BUFFER_BIT_STENCIL |
 245                                  BUFFER_BIT_DEPTH);
 246
 247    if (tri_mask) {
 248       debug_mask("tri", tri_mask);
 249       mask &= ~tri_mask;
 250
 251       if (ctx->API == API_OPENGLES) {
 252          _mesa_meta_Clear(&intel->ctx, tri_mask);
 253       } else {
 254          _mesa_meta_glsl_Clear(&intel->ctx, tri_mask);
 255       }
 256    }
 257
 258    /* Any strange buffers get passed off to swrast */
 259    if (mask) {
 260       debug_mask("swrast", mask);
 261       _swrast_Clear(ctx, mask);
 262    }
 263 }
 264
 265
 266 void
 267 intelInitClearFuncs(struct dd_function_table *functions)
 268 {
 269    functions->Clear = brw_clear;
 270 }