Revert "Reland "Reland "Use conics with w=Inf to describe triangles for the tessellator"""
This reverts commit 99e6f0fcfb44ab9de58d927b30dd6ddd16dd861e.
Reason for revert: Perf regressions
Original change's description:
> Reland "Reland "Use conics with w=Inf to describe triangles for the tessellator""
>
> This is a reland of ff515df5b4549673b4c7f04e41c62f2bd1d4ddc3
>
> Original change's description:
> > Reland "Use conics with w=Inf to describe triangles for the tessellator"
> >
> > This is a reland of 84f70136abfb0af3cddf2ec7e8e2405f154916b0
> >
> > Original change's description:
> > > Use conics with w=Inf to describe triangles for the tessellator
> > >
> > > Previously, only the indirect tessellator could draw triangles, and
> > > only with special index data. Using conics with w=Inf will allow us to
> > > draw triangles with the hardware tessellator as well, in addition to
> > > being able to wean the indirect tessellator off an index buffer.
> > >
> > > Bug: skia:10419
> > > Bug: chromium:1202607
> > > Change-Id: I180af9cb5410c0e0bb25a2edcfb01e17d4a2f590
> > > Reviewed-on: https://skia-review.googlesource.com/c/skia/+/406977
> > > Commit-Queue: Chris Dalton <csmartdalton@google.com>
> > > Reviewed-by: Michael Ludwig <michaelludwig@google.com>
> >
> > Bug: skia:10419
> > Bug: chromium:1202607
> > Change-Id: Ic12b10eaa60fddd212c66757bf7100749ee58d49
> > Reviewed-on: https://skia-review.googlesource.com/c/skia/+/408096
> > Reviewed-by: Robert Phillips <robertphillips@google.com>
> > Commit-Queue: Chris Dalton <csmartdalton@google.com>
>
> TBR=robertphillips@google.com
>
> Bug: skia:10419
> Bug: chromium:1202607
> Change-Id: Id1f8dfa133f446b9f30f2bf8493a3a7b99072e59
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/408616
> Reviewed-by: Chris Dalton <csmartdalton@google.com>
> Commit-Queue: Chris Dalton <csmartdalton@google.com>
TBR=robertphillips@google.com,csmartdalton@google.com,michaelludwig@google.com
Change-Id: I8a4c85bc6863fbe62ed34dc3110370662bacab67
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:10419
Bug: chromium:1202607
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/408677
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
diff --git a/src/gpu/tessellate/GrFillPathShader.cpp b/src/gpu/tessellate/GrFillPathShader.cpp
index 71fd72d..6274845 100644
--- a/src/gpu/tessellate/GrFillPathShader.cpp
+++ b/src/gpu/tessellate/GrFillPathShader.cpp
@@ -72,20 +72,16 @@
GrGLSLUniformHandler* uniformHandler) const {
v->codeAppend(R"(
float4x2 P = float4x2(input_points_0_1, input_points_2_3);
- if (isinf(P[3].y)) { // Is the curve a conic?
+ if (isinf(P[3].y)) {
+ // This curve is actually a conic. Convert the control points to a trapeziodal hull
+ // that circumcscribes the conic.
float w = P[3].x;
- if (isinf(w)) {
- // A conic with w=Inf is an exact triangle.
- P = float4x2(P[0], P[1], P[2], P[2]);
- } else {
- // Convert the control points to a trapeziodal hull that circumcscribes the conic.
- float2 p1w = P[1] * w;
- float T = .51; // Bias outward a bit to ensure we cover the outermost samples.
- float2 c1 = mix(P[0], p1w, T);
- float2 c2 = mix(P[2], p1w, T);
- float iw = 1 / mix(1, w, T);
- P = float4x2(P[0], c1 * iw, c2 * iw, P[2]);
- }
+ float2 p1w = P[1] * w;
+ float T = .51; // Bias outward a bit to ensure we cover the outermost samples.
+ float2 c1 = mix(P[0], p1w, T);
+ float2 c2 = mix(P[2], p1w, T);
+ float iw = 1 / mix(1, w, T);
+ P = float4x2(P[0], c1 * iw, c2 * iw, P[2]);
}
// Translate the points to v0..3 where v0=0.
diff --git a/src/gpu/tessellate/GrMiddleOutPolygonTriangulator.h b/src/gpu/tessellate/GrMiddleOutPolygonTriangulator.h
index fb17db1..b960ab5 100644
--- a/src/gpu/tessellate/GrMiddleOutPolygonTriangulator.h
+++ b/src/gpu/tessellate/GrMiddleOutPolygonTriangulator.h
@@ -13,7 +13,6 @@
#include "include/private/SkTemplates.h"
#include "src/core/SkMathPriv.h"
#include "src/core/SkPathPriv.h"
-#include <limits>
// This class emits a polygon triangulation with a "middle-out" topology. Conceptually, middle-out
// emits one large triangle with vertices on both endpoints and a middle point, then recurses on
@@ -41,12 +40,6 @@
// This class is designed to not know or store all the vertices in the polygon at once. The caller
// pushes each vertex in linear order (perhaps while parsing a path), then rather than relying on
// recursion, we manipulate an O(log N) stack to determine the correct middle-out triangulation.
-//
-// perTriangleVertexAdvance controls how much padding to put after triangles (namely, we append
-// "perTriangleVertexAdvance - 3" vertices of padding after each triangle, including the final one).
-// Padding vertices are filled with infinity. This has the effect, when perTriangleVertexAdvance is
-// 4, of defining a conic with w=Inf for tessellation shaders, which comes out to be an exact
-// triangle.
class GrMiddleOutPolygonTriangulator {
public:
GrMiddleOutPolygonTriangulator(SkPoint* vertexData, int perTriangleVertexAdvance,
@@ -173,10 +166,6 @@
fVertexData[0] = fTop[0].fPoint;
fVertexData[1] = fTop[1].fPoint;
fVertexData[2] = lastPt;
- for (int i = 3; i < fPerTriangleVertexAdvance; ++i) {
- fVertexData[i].set(std::numeric_limits<float>::infinity(),
- std::numeric_limits<float>::infinity());
- }
fVertexData += fPerTriangleVertexAdvance;
}
diff --git a/src/gpu/tessellate/GrPathTessellator.cpp b/src/gpu/tessellate/GrPathTessellator.cpp
index 7fe80ae..24db640 100644
--- a/src/gpu/tessellate/GrPathTessellator.cpp
+++ b/src/gpu/tessellate/GrPathTessellator.cpp
@@ -14,7 +14,6 @@
#include "src/gpu/tessellate/GrMiddleOutPolygonTriangulator.h"
#include "src/gpu/tessellate/GrMidpointContourParser.h"
#include "src/gpu/tessellate/GrStencilPathShader.h"
-#include <limits>
GrPathIndirectTessellator::GrPathIndirectTessellator(const SkMatrix& viewMatrix, const SkPath& path,
DrawInnerFan drawInnerFan)
@@ -93,9 +92,8 @@
}
SkPoint* breadcrumbData = instanceData + numTrianglesAtBeginningOfData * 4;
memcpy(breadcrumbData, p, sizeof(SkPoint) * 3);
- // Mark this instance as a triangle by setting it to a conic with w=Inf.
- breadcrumbData[3].set(std::numeric_limits<float>::infinity(),
- std::numeric_limits<float>::infinity());
+ // Duplicate the final point since it will also be used by the convex hull shader.
+ breadcrumbData[3] = p[2];
++numTrianglesAtBeginningOfData;
}
SkASSERT(count == breadcrumbTriangleList->count());
@@ -124,24 +122,29 @@
// location at each resolve level.
SkPoint* instanceLocations[kMaxResolveLevel + 1];
int runningInstanceCount = 0;
+ if (numTrianglesAtBeginningOfData) {
+ // The caller has already packed "triangleInstanceCount" triangles into 4-point instances
+ // at the beginning of the instance buffer. Add a special-case indirect draw here that will
+ // emit the triangles [P0, P1, P2] from these 4-point instances.
+ SkASSERT(fIndirectDrawCount < indirectLockCnt);
+ GrMiddleOutCubicShader::WriteDrawTrianglesIndirectCmd(&indirectWriter,
+ numTrianglesAtBeginningOfData,
+ fBaseInstance);
+ ++fIndirectDrawCount;
+ runningInstanceCount = numTrianglesAtBeginningOfData;
+ }
SkASSERT(fResolveLevelCounts[0] == 0);
for (int resolveLevel = 1; resolveLevel <= kMaxResolveLevel; ++resolveLevel) {
int instanceCountAtCurrLevel = fResolveLevelCounts[resolveLevel];
- if (resolveLevel == 1) {
- instanceCountAtCurrLevel += numTrianglesAtBeginningOfData;
- }
if (!instanceCountAtCurrLevel) {
SkDEBUGCODE(instanceLocations[resolveLevel] = nullptr;)
continue;
}
instanceLocations[resolveLevel] = instanceData + runningInstanceCount * 4;
- if (resolveLevel == 1) {
- instanceLocations[resolveLevel] += numTrianglesAtBeginningOfData * 4;
- }
SkASSERT(fIndirectDrawCount < indirectLockCnt);
- GrMiddleOutCubicShader::WriteDrawIndirectCmd(&indirectWriter, resolveLevel,
- instanceCountAtCurrLevel,
- fBaseInstance + runningInstanceCount);
+ GrMiddleOutCubicShader::WriteDrawCubicsIndirectCmd(&indirectWriter, resolveLevel,
+ instanceCountAtCurrLevel,
+ fBaseInstance + runningInstanceCount);
++fIndirectDrawCount;
runningInstanceCount += instanceCountAtCurrLevel;
}
diff --git a/src/gpu/tessellate/GrStencilPathShader.cpp b/src/gpu/tessellate/GrStencilPathShader.cpp
index d5643a2..85b1f42 100644
--- a/src/gpu/tessellate/GrStencilPathShader.cpp
+++ b/src/gpu/tessellate/GrStencilPathShader.cpp
@@ -367,25 +367,24 @@
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const auto& shader = args.fGeomProc.cast<GrMiddleOutCubicShader>();
args.fVaryingHandler->emitAttributes(shader);
- args.fVertBuilder->defineConstantf("float", "kInverseMaxVertexID", "(1.0 / float(%d))",
- 1 << kMaxResolveLevel);
+ args.fVertBuilder->defineConstantf("int", "kMaxVertexID", "%i", 1 << kMaxResolveLevel);
+ args.fVertBuilder->defineConstantf("float", "kInverseMaxVertexID",
+ "(1.0 / float(kMaxVertexID))");
args.fVertBuilder->insertFunction(kUnpackRationalCubicFn);
args.fVertBuilder->insertFunction(kEvalRationalCubicFn);
- args.fVertBuilder->codeAppendf(R"(
+ args.fVertBuilder->codeAppend(R"(
float2 pos;
- if (isinf(inputPoints_2_3.z)) {
- // A conic with w=Inf is an exact triangle.
- int idx = sk_VertexID >> %d/*kMaxResolveLevel - 1*/;
- pos = (idx < 1) ? inputPoints_0_1.xy
- : (idx == 1) ? inputPoints_0_1.zw
- : inputPoints_2_3.xy;
+ if (sk_VertexID > kMaxVertexID) {
+ // This is a special index value that instructs us to emit a specific point.
+ pos = ((sk_VertexID & 3) == 0) ? inputPoints_0_1.xy :
+ ((sk_VertexID & 2) == 0) ? inputPoints_0_1.zw : inputPoints_2_3.xy;
} else {
// Evaluate the cubic at T = (sk_VertexID / 2^kMaxResolveLevel).
float T = float(sk_VertexID) * kInverseMaxVertexID;
float4x3 P = unpack_rational_cubic(inputPoints_0_1.xy, inputPoints_0_1.zw,
inputPoints_2_3.xy, inputPoints_2_3.zw);
pos = eval_rational_cubic(P, T);
- })", kMaxResolveLevel - 1);
+ })");
GrShaderVar vertexPos("pos", kFloat2_GrSLType);
if (!shader.viewMatrix().isIdentity()) {
diff --git a/src/gpu/tessellate/GrStencilPathShader.h b/src/gpu/tessellate/GrStencilPathShader.h
index 203a184..7236dea 100644
--- a/src/gpu/tessellate/GrStencilPathShader.h
+++ b/src/gpu/tessellate/GrStencilPathShader.h
@@ -152,8 +152,9 @@
// Configures an indirect draw to render cubic instances with 2^resolveLevel evenly-spaced (in
// the parametric sense) line segments.
- static void WriteDrawIndirectCmd(GrDrawIndexedIndirectWriter* indirectWriter, int resolveLevel,
- uint32_t instanceCount, uint32_t baseInstance) {
+ static void WriteDrawCubicsIndirectCmd(GrDrawIndexedIndirectWriter* indirectWriter,
+ int resolveLevel, uint32_t instanceCount,
+ uint32_t baseInstance) {
SkASSERT(resolveLevel > 0 && resolveLevel <= GrTessellationPathRenderer::kMaxResolveLevel);
// Starting at baseIndex=3, the index buffer triangulates a cubic with 2^kMaxResolveLevel
// line segments. Each index value corresponds to a parametric T value on the curve. Since
@@ -163,6 +164,15 @@
indirectWriter->writeIndexed(indexCount, 3, instanceCount, baseInstance, 0);
}
+ // For performance reasons we can often express triangles as an indirect cubic draw and sneak
+ // them in alongside the other indirect draws. This method configures an indirect draw to emit
+ // the triangle [P0, P1, P2] from a 4-point instance.
+ static void WriteDrawTrianglesIndirectCmd(GrDrawIndexedIndirectWriter* indirectWriter,
+ uint32_t instanceCount, uint32_t baseInstance) {
+ // Indices 0,1,2 have special index values that emit points P0, P1, and P2 respectively.
+ indirectWriter->writeIndexed(3, 0, instanceCount, baseInstance, 0);
+ }
+
// Returns the index buffer that should be bound when drawing with this shader.
// (Our vertex shader uses raw index values directly, so there is no vertex buffer.)
static sk_sp<const GrGpuBuffer> FindOrMakeMiddleOutIndexBuffer(GrResourceProvider*);
