src/mesa/drivers/dri/i965/brw_clear.c - platform/external/mesa3d - Git at Google

 /**************************************************************************
  *
  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
  * Copyright 2009, 2012 Intel Corporation.
  * All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sub license, and/or sell copies of the Software, and to
  * permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
  *
  * The above copyright notice and this permission notice (including the
  * next paragraph) shall be included in all copies or substantial portions
  * of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
  **************************************************************************/

 #include "main/glheader.h"
 #include "main/mtypes.h"
 #include "main/condrender.h"
 #include "swrast/swrast.h"
 #include "drivers/common/meta.h"

 #include "intel_batchbuffer.h"
 #include "intel_context.h"
 #include "intel_blit.h"
 #include "intel_clear.h"
 #include "intel_fbo.h"
 #include "intel_mipmap_tree.h"
 #include "intel_regions.h"

 #define FILE_DEBUG_FLAG DEBUG_BLIT

 static const char *buffer_names[] = {
    [BUFFER_FRONT_LEFT] = "front",
    [BUFFER_BACK_LEFT] = "back",
    [BUFFER_FRONT_RIGHT] = "front right",
    [BUFFER_BACK_RIGHT] = "back right",
    [BUFFER_DEPTH] = "depth",
    [BUFFER_STENCIL] = "stencil",
    [BUFFER_ACCUM] = "accum",
    [BUFFER_AUX0] = "aux0",
    [BUFFER_COLOR0] = "color0",
    [BUFFER_COLOR1] = "color1",
    [BUFFER_COLOR2] = "color2",
    [BUFFER_COLOR3] = "color3",
    [BUFFER_COLOR4] = "color4",
    [BUFFER_COLOR5] = "color5",
    [BUFFER_COLOR6] = "color6",
    [BUFFER_COLOR7] = "color7",
 };

 static void
 debug_mask(const char *name, GLbitfield mask)
 {
    GLuint i;

    if (unlikely(INTEL_DEBUG & DEBUG_BLIT)) {
       DBG("%s clear:", name);
       for (i = 0; i < BUFFER_COUNT; i++) {
 	 if (mask & (1 << i))
 	    DBG(" %s", buffer_names[i]);
       }
       DBG("\n");
    }
 }

 /**
  * Implements fast depth clears on gen6+.
  *
  * Fast clears basically work by setting a flag in each of the subspans
  * represented in the HiZ buffer that says "When you need the depth values for
  * this subspan, it's the hardware's current clear value."  Then later rendering
  * can just use the static clear value instead of referencing memory.
  *
  * The tricky part of the implementation is that you have to have the clear
  * value that was used on the depth buffer in place for all further rendering,
  * at least until a resolve to the real depth buffer happens.
  */
 static bool
 brw_fast_clear_depth(struct gl_context *ctx)
 {
    struct intel_context *intel = intel_context(ctx);
    struct gl_framebuffer *fb = ctx->DrawBuffer;
    struct intel_renderbuffer *depth_irb =
       intel_get_renderbuffer(fb, BUFFER_DEPTH);
    struct intel_mipmap_tree *mt = depth_irb->mt;

    if (intel->gen < 6)
       return false;

    if (!mt->hiz_mt)
       return false;

    /* We only handle full buffer clears -- otherwise you'd have to track whether
     * a previous clear had happened at a different clear value and resolve it
     * first.
     */
    if (ctx->Scissor.Enabled) {
       perf_debug("Failed to fast clear depth due to scissor being enabled.  "
                  "Possible 5%% performance win if avoided.\n");
       return false;
    }

    /* The rendered area has to be 8x4 samples, not resolved pixels, so we look
     * at the miptree slice dimensions instead of renderbuffer size.
     */
    if (mt->level[depth_irb->mt_level].width % 8 != 0 ||
        mt->level[depth_irb->mt_level].height % 4 != 0) {
       perf_debug("Failed to fast clear depth due to width/height %d,%d not "
                  "being aligned to 8,4.  Possible 5%% performance win if "
                  "avoided\n",
                  mt->level[depth_irb->mt_level].width,
                  mt->level[depth_irb->mt_level].height);
       return false;
    }

    uint32_t depth_clear_value;
    switch (mt->format) {
    case MESA_FORMAT_Z32_FLOAT_X24S8:
    case MESA_FORMAT_S8_Z24:
       /* From the Sandy Bridge PRM, volume 2 part 1, page 314:
        *
        *     "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
        *      enabled (the legacy method of clearing must be performed):
        *
        *      - If the depth buffer format is D32_FLOAT_S8X24_UINT or
        *        D24_UNORM_S8_UINT.
        */
       return false;

    case MESA_FORMAT_Z32_FLOAT:
       depth_clear_value = float_as_int(ctx->Depth.Clear);
       break;

    case MESA_FORMAT_Z16:
       /* From the Sandy Bridge PRM, volume 2 part 1, page 314:
        *
        *     "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
        *      enabled (the legacy method of clearing must be performed):
        *
        *      - DevSNB{W/A}]: When depth buffer format is D16_UNORM and the
        *        width of the map (LOD0) is not multiple of 16, fast clear
        *        optimization must be disabled.
        */
       if (intel->gen == 6 && (mt->level[depth_irb->mt_level].width % 16) != 0)
 	 return false;
       /* FALLTHROUGH */

    default:
       depth_clear_value = fb->_DepthMax * ctx->Depth.Clear;
       break;
    }

    /* If we're clearing to a new clear value, then we need to resolve any clear
     * flags out of the HiZ buffer into the real depth buffer.
     */
    if (mt->depth_clear_value != depth_clear_value) {
       intel_miptree_all_slices_resolve_depth(intel, mt);
       mt->depth_clear_value = depth_clear_value;
    }

    /* From the Sandy Bridge PRM, volume 2 part 1, page 313:
     *
     *     "If other rendering operations have preceded this clear, a
     *      PIPE_CONTROL with write cache flush enabled and Z-inhibit disabled
     *      must be issued before the rectangle primitive used for the depth
     *      buffer clear operation.
     */
    intel_batchbuffer_emit_mi_flush(intel);

    intel_hiz_exec(intel, mt, depth_irb->mt_level, depth_irb->mt_layer,
 		  GEN6_HIZ_OP_DEPTH_CLEAR);

    if (intel->gen == 6) {
       /* From the Sandy Bridge PRM, volume 2 part 1, page 314:
        *
        *     "DevSNB, DevSNB-B{W/A}]: Depth buffer clear pass must be followed
        *      by a PIPE_CONTROL command with DEPTH_STALL bit set and Then
        *      followed by Depth FLUSH'
       */
       intel_batchbuffer_emit_mi_flush(intel);
    }

    /* Now, the HiZ buffer contains data that needs to be resolved to the depth
     * buffer.
     */
    intel_renderbuffer_set_needs_depth_resolve(depth_irb);

    return true;
 }

 /**
  * Called by ctx->Driver.Clear.
  */
 static void
 brw_clear(struct gl_context *ctx, GLbitfield mask)
 {
    struct intel_context *intel = intel_context(ctx);

    if (!_mesa_check_conditional_render(ctx))
       return;

    if (mask & (BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT)) {
       intel->front_buffer_dirty = true;
    }

    intel_prepare_render(intel);

    if (mask & BUFFER_BIT_DEPTH) {
       if (brw_fast_clear_depth(ctx)) {
 	 DBG("fast clear: depth\n");
 	 mask &= ~BUFFER_BIT_DEPTH;
       }
    }

    GLbitfield tri_mask = mask & (BUFFER_BITS_COLOR |
 				 BUFFER_BIT_STENCIL |
 				 BUFFER_BIT_DEPTH);

    if (tri_mask) {
       debug_mask("tri", tri_mask);
       mask &= ~tri_mask;

       if (ctx->API == API_OPENGLES) {
          _mesa_meta_Clear(&intel->ctx, tri_mask);
       } else {
          _mesa_meta_glsl_Clear(&intel->ctx, tri_mask);
       }
    }

    /* Any strange buffers get passed off to swrast */
    if (mask) {
       debug_mask("swrast", mask);
       _swrast_Clear(ctx, mask);
    }
 }


 void
 intelInitClearFuncs(struct dd_function_table *functions)
 {
    functions->Clear = brw_clear;
 }
	/**************************************************************************
	*
	* Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
	* Copyright 2009, 2012 Intel Corporation.
	* All Rights Reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the
	* "Software"), to deal in the Software without restriction, including
	* without limitation the rights to use, copy, modify, merge, publish,
	* distribute, sub license, and/or sell copies of the Software, and to
	* permit persons to whom the Software is furnished to do so, subject to
	* the following conditions:
	*
	* The above copyright notice and this permission notice (including the
	* next paragraph) shall be included in all copies or substantial portions
	* of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
	* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
	* IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
	* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
	* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
	* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*
	**************************************************************************/

	#include "main/glheader.h"
	#include "main/mtypes.h"
	#include "main/condrender.h"
	#include "swrast/swrast.h"
	#include "drivers/common/meta.h"

	#include "intel_batchbuffer.h"
	#include "intel_context.h"
	#include "intel_blit.h"
	#include "intel_clear.h"
	#include "intel_fbo.h"
	#include "intel_mipmap_tree.h"
	#include "intel_regions.h"

	#define FILE_DEBUG_FLAG DEBUG_BLIT

	static const char *buffer_names[] = {
	[BUFFER_FRONT_LEFT] = "front",
	[BUFFER_BACK_LEFT] = "back",
	[BUFFER_FRONT_RIGHT] = "front right",
	[BUFFER_BACK_RIGHT] = "back right",
	[BUFFER_DEPTH] = "depth",
	[BUFFER_STENCIL] = "stencil",
	[BUFFER_ACCUM] = "accum",
	[BUFFER_AUX0] = "aux0",
	[BUFFER_COLOR0] = "color0",
	[BUFFER_COLOR1] = "color1",
	[BUFFER_COLOR2] = "color2",
	[BUFFER_COLOR3] = "color3",
	[BUFFER_COLOR4] = "color4",
	[BUFFER_COLOR5] = "color5",
	[BUFFER_COLOR6] = "color6",
	[BUFFER_COLOR7] = "color7",
	};

	static void
	debug_mask(const char *name, GLbitfield mask)
	{
	GLuint i;

	if (unlikely(INTEL_DEBUG & DEBUG_BLIT)) {
	DBG("%s clear:", name);
	for (i = 0; i < BUFFER_COUNT; i++) {
	if (mask & (1 << i))
	DBG(" %s", buffer_names[i]);
	}
	DBG("\n");
	}
	}

	/**
	* Implements fast depth clears on gen6+.
	*
	* Fast clears basically work by setting a flag in each of the subspans
	* represented in the HiZ buffer that says "When you need the depth values for
	* this subspan, it's the hardware's current clear value." Then later rendering
	* can just use the static clear value instead of referencing memory.
	*
	* The tricky part of the implementation is that you have to have the clear
	* value that was used on the depth buffer in place for all further rendering,
	* at least until a resolve to the real depth buffer happens.
	*/
	static bool
	brw_fast_clear_depth(struct gl_context *ctx)
	{
	struct intel_context *intel = intel_context(ctx);
	struct gl_framebuffer *fb = ctx->DrawBuffer;
	struct intel_renderbuffer *depth_irb =
	intel_get_renderbuffer(fb, BUFFER_DEPTH);
	struct intel_mipmap_tree *mt = depth_irb->mt;

	if (intel->gen < 6)
	return false;

	if (!mt->hiz_mt)
	return false;

	/* We only handle full buffer clears -- otherwise you'd have to track whether
	* a previous clear had happened at a different clear value and resolve it
	* first.
	*/
	if (ctx->Scissor.Enabled) {
	perf_debug("Failed to fast clear depth due to scissor being enabled. "
	"Possible 5%% performance win if avoided.\n");
	return false;
	}

	/* The rendered area has to be 8x4 samples, not resolved pixels, so we look
	* at the miptree slice dimensions instead of renderbuffer size.
	*/
	if (mt->level[depth_irb->mt_level].width % 8 != 0 \|\|
	mt->level[depth_irb->mt_level].height % 4 != 0) {
	perf_debug("Failed to fast clear depth due to width/height %d,%d not "
	"being aligned to 8,4. Possible 5%% performance win if "
	"avoided\n",
	mt->level[depth_irb->mt_level].width,
	mt->level[depth_irb->mt_level].height);
	return false;
	}

	uint32_t depth_clear_value;
	switch (mt->format) {
	case MESA_FORMAT_Z32_FLOAT_X24S8:
	case MESA_FORMAT_S8_Z24:
	/* From the Sandy Bridge PRM, volume 2 part 1, page 314:
	*
	* "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
	* enabled (the legacy method of clearing must be performed):
	*
	* - If the depth buffer format is D32_FLOAT_S8X24_UINT or
	* D24_UNORM_S8_UINT.
	*/
	return false;

	case MESA_FORMAT_Z32_FLOAT:
	depth_clear_value = float_as_int(ctx->Depth.Clear);
	break;

	case MESA_FORMAT_Z16:
	/* From the Sandy Bridge PRM, volume 2 part 1, page 314:
	*
	* "[DevSNB+]: Several cases exist where Depth Buffer Clear cannot be
	* enabled (the legacy method of clearing must be performed):
	*
	* - DevSNB{W/A}]: When depth buffer format is D16_UNORM and the
	* width of the map (LOD0) is not multiple of 16, fast clear
	* optimization must be disabled.
	*/
	if (intel->gen == 6 && (mt->level[depth_irb->mt_level].width % 16) != 0)
	return false;
	/* FALLTHROUGH */

	default:
	depth_clear_value = fb->_DepthMax * ctx->Depth.Clear;
	break;
	}

	/* If we're clearing to a new clear value, then we need to resolve any clear
	* flags out of the HiZ buffer into the real depth buffer.
	*/
	if (mt->depth_clear_value != depth_clear_value) {
	intel_miptree_all_slices_resolve_depth(intel, mt);
	mt->depth_clear_value = depth_clear_value;
	}

	/* From the Sandy Bridge PRM, volume 2 part 1, page 313:
	*
	* "If other rendering operations have preceded this clear, a
	* PIPE_CONTROL with write cache flush enabled and Z-inhibit disabled
	* must be issued before the rectangle primitive used for the depth
	* buffer clear operation.
	*/
	intel_batchbuffer_emit_mi_flush(intel);

	intel_hiz_exec(intel, mt, depth_irb->mt_level, depth_irb->mt_layer,
	GEN6_HIZ_OP_DEPTH_CLEAR);

	if (intel->gen == 6) {
	/* From the Sandy Bridge PRM, volume 2 part 1, page 314:
	*
	* "DevSNB, DevSNB-B{W/A}]: Depth buffer clear pass must be followed
	* by a PIPE_CONTROL command with DEPTH_STALL bit set and Then
	* followed by Depth FLUSH'
	*/
	intel_batchbuffer_emit_mi_flush(intel);
	}

	/* Now, the HiZ buffer contains data that needs to be resolved to the depth
	* buffer.
	*/
	intel_renderbuffer_set_needs_depth_resolve(depth_irb);

	return true;
	}

	/**
	* Called by ctx->Driver.Clear.
	*/
	static void
	brw_clear(struct gl_context *ctx, GLbitfield mask)
	{
	struct intel_context *intel = intel_context(ctx);

	if (!_mesa_check_conditional_render(ctx))
	return;

	if (mask & (BUFFER_BIT_FRONT_LEFT \| BUFFER_BIT_FRONT_RIGHT)) {
	intel->front_buffer_dirty = true;
	}

	intel_prepare_render(intel);

	if (mask & BUFFER_BIT_DEPTH) {
	if (brw_fast_clear_depth(ctx)) {
	DBG("fast clear: depth\n");
	mask &= ~BUFFER_BIT_DEPTH;
	}
	}

	GLbitfield tri_mask = mask & (BUFFER_BITS_COLOR \|
	BUFFER_BIT_STENCIL \|
	BUFFER_BIT_DEPTH);

	if (tri_mask) {
	debug_mask("tri", tri_mask);
	mask &= ~tri_mask;

	if (ctx->API == API_OPENGLES) {
	_mesa_meta_Clear(&intel->ctx, tri_mask);
	} else {
	_mesa_meta_glsl_Clear(&intel->ctx, tri_mask);
	}
	}

	/* Any strange buffers get passed off to swrast */
	if (mask) {
	debug_mask("swrast", mask);
	_swrast_Clear(ctx, mask);
	}
	}


	void
	intelInitClearFuncs(struct dd_function_table *functions)
	{
	functions->Clear = brw_clear;
	}