/**
* \brief Call this after drawing to mark which buffers need resolving
*
* If the depth buffer was written to and if it has an accompanying HiZ
* buffer, then mark that it needs a depth resolve.
*
* If the color buffer is a multisample window system buffer, then
* mark that it needs a downsample.
*/
static void brw_postdraw_set_buffers_need_resolve(struct brw_context *brw)
{
struct gl_context *ctx = &brw->ctx;
struct gl_framebuffer *fb = ctx->DrawBuffer;
struct intel_renderbuffer *front_irb = NULL;
struct intel_renderbuffer *back_irb = intel_get_renderbuffer(fb, BUFFER_BACK_LEFT);
struct intel_renderbuffer *depth_irb = intel_get_renderbuffer(fb, BUFFER_DEPTH);
struct gl_renderbuffer_attachment *depth_att = &fb->Attachment[BUFFER_DEPTH];
if (brw->is_front_buffer_rendering)
front_irb = intel_get_renderbuffer(fb, BUFFER_FRONT_LEFT);
if (front_irb)
intel_renderbuffer_set_needs_downsample(front_irb);
if (back_irb)
intel_renderbuffer_set_needs_downsample(back_irb);
if (depth_irb && ctx->Depth.Mask)
intel_renderbuffer_att_set_needs_depth_resolve(depth_att);
}
/**
* \brief Call this after drawing to mark which buffers need resolving
*
* If the depth buffer was written to and if it has an accompanying HiZ
* buffer, then mark that it needs a depth resolve.
*
* If the color buffer is a multisample window system buffer, then
* mark that it needs a downsample.
*
* Also mark any render targets which will be textured as needing a render
* cache flush.
*/
static void
brw_postdraw_set_buffers_need_resolve(struct brw_context *brw)
{
struct gl_context *ctx = &brw->ctx;
struct gl_framebuffer *fb = ctx->DrawBuffer;
struct intel_renderbuffer *front_irb = NULL;
struct intel_renderbuffer *back_irb = intel_get_renderbuffer(fb, BUFFER_BACK_LEFT);
struct intel_renderbuffer *depth_irb = intel_get_renderbuffer(fb, BUFFER_DEPTH);
struct intel_renderbuffer *stencil_irb = intel_get_renderbuffer(fb, BUFFER_STENCIL);
struct gl_renderbuffer_attachment *depth_att = &fb->Attachment[BUFFER_DEPTH];
if (brw_is_front_buffer_drawing(fb))
front_irb = intel_get_renderbuffer(fb, BUFFER_FRONT_LEFT);
if (front_irb)
front_irb->need_downsample = true;
if (back_irb)
back_irb->need_downsample = true;
if (depth_irb && ctx->Depth.Mask) {
intel_renderbuffer_att_set_needs_depth_resolve(depth_att);
brw_render_cache_set_add_bo(brw, depth_irb->mt->bo);
}
if (ctx->Extensions.ARB_stencil_texturing &&
stencil_irb && ctx->Stencil._WriteEnabled) {
brw_render_cache_set_add_bo(brw, stencil_irb->mt->bo);
}
for (int i = 0; i < fb->_NumColorDrawBuffers; i++) {
struct intel_renderbuffer *irb =
intel_renderbuffer(fb->_ColorDrawBuffers[i]);
if (irb)
brw_render_cache_set_add_bo(brw, irb->mt->bo);
}
}
/**
* 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 brw_context *brw = brw_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;
struct gl_renderbuffer_attachment *depth_att = &fb->Attachment[BUFFER_DEPTH];
if (brw->gen < 6)
return false;
if (!intel_renderbuffer_has_hiz(depth_irb))
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.EnableFlags & 1) && !noop_scissor(ctx, fb)) {
perf_debug("Failed to fast clear %dx%d depth because of scissors. "
"Possible 5%% performance win if avoided.\n",
mt->logical_width0, mt->logical_height0);
return false;
}
uint32_t depth_clear_value;
switch (mt->format) {
case MESA_FORMAT_Z32_FLOAT_S8X24_UINT:
case MESA_FORMAT_Z24_UNORM_S8_UINT:
/* 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_Z_FLOAT32:
depth_clear_value = float_as_int(ctx->Depth.Clear);
break;
case MESA_FORMAT_Z_UNORM16:
/* 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 (brw->gen == 6 &&
(minify(mt->physical_width0,
depth_irb->mt_level - mt->first_level) % 16) != 0)
return false;
/* FALLTHROUGH */
default:
if (brw->gen >= 8)
depth_clear_value = float_as_int(ctx->Depth.Clear);
else
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(brw, 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.
*/
brw_emit_mi_flush(brw);
if (fb->MaxNumLayers > 0) {
for (unsigned layer = 0; layer < depth_irb->layer_count; layer++) {
intel_hiz_exec(brw, mt, depth_irb->mt_level,
depth_irb->mt_layer + layer,
GEN6_HIZ_OP_DEPTH_CLEAR);
}
} else {
intel_hiz_exec(brw, mt, depth_irb->mt_level, depth_irb->mt_layer,
GEN6_HIZ_OP_DEPTH_CLEAR);
}
if (brw->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'
*/
brw_emit_mi_flush(brw);
}
/* Now, the HiZ buffer contains data that needs to be resolved to the depth
* buffer.
*/
intel_renderbuffer_att_set_needs_depth_resolve(depth_att);
return true;
}
