src/gpu/ops/GrNonAAStrokeRectOp.cpp - skia - Git at Google

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "GrColor.h"
 #include "GrDefaultGeoProcFactory.h"
 #include "GrDrawOpTest.h"
 #include "GrMeshDrawOp.h"
 #include "GrOpFlushState.h"
 #include "GrRectOpFactory.h"
 #include "GrSimpleMeshDrawOpHelper.h"
 #include "SkRandom.h"
 #include "SkStrokeRec.h"

 /*  create a triangle strip that strokes the specified rect. There are 8
     unique vertices, but we repeat the last 2 to close up. Alternatively we
     could use an indices array, and then only send 8 verts, but not sure that
     would be faster.
     */
 static void init_stroke_rect_strip(SkPoint verts[10], const SkRect& rect, SkScalar width) {
     const SkScalar rad = SkScalarHalf(width);

     verts[0].set(rect.fLeft + rad, rect.fTop + rad);
     verts[1].set(rect.fLeft - rad, rect.fTop - rad);
     verts[2].set(rect.fRight - rad, rect.fTop + rad);
     verts[3].set(rect.fRight + rad, rect.fTop - rad);
     verts[4].set(rect.fRight - rad, rect.fBottom - rad);
     verts[5].set(rect.fRight + rad, rect.fBottom + rad);
     verts[6].set(rect.fLeft + rad, rect.fBottom - rad);
     verts[7].set(rect.fLeft - rad, rect.fBottom + rad);
     verts[8] = verts[0];
     verts[9] = verts[1];

     // TODO: we should be catching this higher up the call stack and just draw a single
     // non-AA rect
     if (2*rad >= rect.width()) {
         verts[0].fX = verts[2].fX = verts[4].fX = verts[6].fX = verts[8].fX = rect.centerX();
     }
     if (2*rad >= rect.height()) {
         verts[0].fY = verts[2].fY = verts[4].fY = verts[6].fY = verts[8].fY = rect.centerY();
     }
 }

 // Allow all hairlines and all miters, so long as the miter limit doesn't produce beveled corners.
 inline static bool allowed_stroke(const SkStrokeRec& stroke) {
     SkASSERT(stroke.getStyle() == SkStrokeRec::kStroke_Style ||
              stroke.getStyle() == SkStrokeRec::kHairline_Style);
     return !stroke.getWidth() ||
            (stroke.getJoin() == SkPaint::kMiter_Join && stroke.getMiter() > SK_ScalarSqrt2);
 }

 namespace {

 class NonAAStrokeRectOp final : public GrMeshDrawOp {
 private:
     using Helper = GrSimpleMeshDrawOpHelper;

 public:
     DEFINE_OP_CLASS_ID

     const char* name() const override { return "NonAAStrokeRectOp"; }

     void visitProxies(const VisitProxyFunc& func) const override {
         fHelper.visitProxies(func);
     }

     SkString dumpInfo() const override {
         SkString string;
         string.appendf(
                 "Color: 0x%08x, Rect [L: %.2f, T: %.2f, R: %.2f, B: %.2f], "
                 "StrokeWidth: %.2f\n",
                 fColor, fRect.fLeft, fRect.fTop, fRect.fRight, fRect.fBottom, fStrokeWidth);
         string += fHelper.dumpInfo();
         string += INHERITED::dumpInfo();
         return string;
     }

     static std::unique_ptr<GrDrawOp> Make(GrContext* context,
                                           GrPaint&& paint,
                                           const SkMatrix& viewMatrix,
                                           const SkRect& rect,
                                           const SkStrokeRec& stroke,
                                           GrAAType aaType) {
         if (!allowed_stroke(stroke)) {
             return nullptr;
         }
         Helper::Flags flags = Helper::Flags::kNone;
         // Depending on sub-pixel coordinates and the particular GPU, we may lose a corner of
         // hairline rects. We jam all the vertices to pixel centers to avoid this, but not
         // when MSAA is enabled because it can cause ugly artifacts.
         if (stroke.getStyle() == SkStrokeRec::kHairline_Style && aaType != GrAAType::kMSAA) {
             flags |= Helper::Flags::kSnapVerticesToPixelCenters;
         }
         return Helper::FactoryHelper<NonAAStrokeRectOp>(context, std::move(paint), flags,
                                                         viewMatrix, rect,
                                                         stroke, aaType);
     }

     NonAAStrokeRectOp(const Helper::MakeArgs& helperArgs, GrColor color, Helper::Flags flags,
                       const SkMatrix& viewMatrix, const SkRect& rect, const SkStrokeRec& stroke,
                       GrAAType aaType)
             : INHERITED(ClassID()), fHelper(helperArgs, aaType, flags) {
         fColor = color;
         fViewMatrix = viewMatrix;
         fRect = rect;
         // Sort the rect for hairlines
         fRect.sort();
         fStrokeWidth = stroke.getWidth();

         SkScalar rad = SkScalarHalf(fStrokeWidth);
         SkRect bounds = rect;
         bounds.outset(rad, rad);

         // If our caller snaps to pixel centers then we have to round out the bounds
         if (flags & Helper::Flags::kSnapVerticesToPixelCenters) {
             viewMatrix.mapRect(&bounds);
             // We want to be consistent with how we snap non-aa lines. To match what we do in
             // GrGLSLVertexShaderBuilder, we first floor all the vertex values and then add half a
             // pixel to force us to pixel centers.
             bounds.set(SkScalarFloorToScalar(bounds.fLeft),
                        SkScalarFloorToScalar(bounds.fTop),
                        SkScalarFloorToScalar(bounds.fRight),
                        SkScalarFloorToScalar(bounds.fBottom));
             bounds.offset(0.5f, 0.5f);
             this->setBounds(bounds, HasAABloat::kNo, IsZeroArea::kNo);
         } else {
             this->setTransformedBounds(bounds, fViewMatrix, HasAABloat::kNo, IsZeroArea::kNo);
         }
     }

     FixedFunctionFlags fixedFunctionFlags() const override { return fHelper.fixedFunctionFlags(); }

     RequiresDstTexture finalize(const GrCaps& caps, const GrAppliedClip* clip,
                                 GrPixelConfigIsClamped dstIsClamped) override {
         return fHelper.xpRequiresDstTexture(caps, clip, dstIsClamped,
                                             GrProcessorAnalysisCoverage::kNone, &fColor);
     }

 private:
     void onPrepareDraws(Target* target) override {
         sk_sp<GrGeometryProcessor> gp;
         {
             using namespace GrDefaultGeoProcFactory;
             Color color(fColor);
             LocalCoords::Type localCoordsType = fHelper.usesLocalCoords()
                                                         ? LocalCoords::kUsePosition_Type
                                                         : LocalCoords::kUnused_Type;
             gp = GrDefaultGeoProcFactory::Make(color, Coverage::kSolid_Type, localCoordsType,
                                                fViewMatrix);
         }

         static constexpr size_t kVertexStride = sizeof(GrDefaultGeoProcFactory::PositionAttr);

         SkASSERT(kVertexStride == gp->debugOnly_vertexStride());

         int vertexCount = kVertsPerHairlineRect;
         if (fStrokeWidth > 0) {
             vertexCount = kVertsPerStrokeRect;
         }

         const GrBuffer* vertexBuffer;
         int firstVertex;

         void* verts =
                 target->makeVertexSpace(kVertexStride, vertexCount, &vertexBuffer, &firstVertex);

         if (!verts) {
             SkDebugf("Could not allocate vertices\n");
             return;
         }

         SkPoint* vertex = reinterpret_cast<SkPoint*>(verts);

         GrPrimitiveType primType;
         if (fStrokeWidth > 0) {
             primType = GrPrimitiveType::kTriangleStrip;
             init_stroke_rect_strip(vertex, fRect, fStrokeWidth);
         } else {
             // hairline
             primType = GrPrimitiveType::kLineStrip;
             vertex[0].set(fRect.fLeft, fRect.fTop);
             vertex[1].set(fRect.fRight, fRect.fTop);
             vertex[2].set(fRect.fRight, fRect.fBottom);
             vertex[3].set(fRect.fLeft, fRect.fBottom);
             vertex[4].set(fRect.fLeft, fRect.fTop);
         }

         GrMesh mesh(primType);
         mesh.setNonIndexedNonInstanced(vertexCount);
         mesh.setVertexData(vertexBuffer, firstVertex);
         target->draw(gp.get(), fHelper.makePipeline(target), mesh);
     }

     bool onCombineIfPossible(GrOp* t, const GrCaps&) override {
         // NonAA stroke rects cannot combine right now
         // TODO make these combinable.
         return false;
     }

     Helper fHelper;
     GrColor fColor;
     SkMatrix fViewMatrix;
     SkRect fRect;
     SkScalar fStrokeWidth;

     const static int kVertsPerHairlineRect = 5;
     const static int kVertsPerStrokeRect = 10;

     typedef GrMeshDrawOp INHERITED;
 };

 }  // anonymous namespace

 namespace GrRectOpFactory {
 std::unique_ptr<GrDrawOp> MakeNonAAStroke(GrContext* context,
                                           GrPaint&& paint,
                                           const SkMatrix& viewMatrix,
                                           const SkRect& rect,
                                           const SkStrokeRec& stroke,
                                           GrAAType aaType) {
     return NonAAStrokeRectOp::Make(context, std::move(paint), viewMatrix, rect, stroke, aaType);
 }
 }  // namespace GrRectOpFactory

 #if GR_TEST_UTILS

 GR_DRAW_OP_TEST_DEFINE(NonAAStrokeRectOp) {
     SkMatrix viewMatrix = GrTest::TestMatrix(random);
     SkRect rect = GrTest::TestRect(random);
     SkScalar strokeWidth = random->nextBool() ? 0.0f : 2.0f;
     SkPaint strokePaint;
     strokePaint.setStrokeWidth(strokeWidth);
     strokePaint.setStyle(SkPaint::kStroke_Style);
     strokePaint.setStrokeJoin(SkPaint::kMiter_Join);
     SkStrokeRec strokeRec(strokePaint);
     GrAAType aaType = GrAAType::kNone;
     if (fsaaType == GrFSAAType::kUnifiedMSAA) {
         aaType = random->nextBool() ? GrAAType::kMSAA : GrAAType::kNone;
     }
     return NonAAStrokeRectOp::Make(context, std::move(paint), viewMatrix, rect, strokeRec, aaType);
 }

 #endif
	/*
	* Copyright 2015 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "GrColor.h"
	#include "GrDefaultGeoProcFactory.h"
	#include "GrDrawOpTest.h"
	#include "GrMeshDrawOp.h"
	#include "GrOpFlushState.h"
	#include "GrRectOpFactory.h"
	#include "GrSimpleMeshDrawOpHelper.h"
	#include "SkRandom.h"
	#include "SkStrokeRec.h"

	/* create a triangle strip that strokes the specified rect. There are 8
	unique vertices, but we repeat the last 2 to close up. Alternatively we
	could use an indices array, and then only send 8 verts, but not sure that
	would be faster.
	*/
	static void init_stroke_rect_strip(SkPoint verts[10], const SkRect& rect, SkScalar width) {
	const SkScalar rad = SkScalarHalf(width);

	verts[0].set(rect.fLeft + rad, rect.fTop + rad);
	verts[1].set(rect.fLeft - rad, rect.fTop - rad);
	verts[2].set(rect.fRight - rad, rect.fTop + rad);
	verts[3].set(rect.fRight + rad, rect.fTop - rad);
	verts[4].set(rect.fRight - rad, rect.fBottom - rad);
	verts[5].set(rect.fRight + rad, rect.fBottom + rad);
	verts[6].set(rect.fLeft + rad, rect.fBottom - rad);
	verts[7].set(rect.fLeft - rad, rect.fBottom + rad);
	verts[8] = verts[0];
	verts[9] = verts[1];

	// TODO: we should be catching this higher up the call stack and just draw a single
	// non-AA rect
	if (2*rad >= rect.width()) {
	verts[0].fX = verts[2].fX = verts[4].fX = verts[6].fX = verts[8].fX = rect.centerX();
	}
	if (2*rad >= rect.height()) {
	verts[0].fY = verts[2].fY = verts[4].fY = verts[6].fY = verts[8].fY = rect.centerY();
	}
	}

	// Allow all hairlines and all miters, so long as the miter limit doesn't produce beveled corners.
	inline static bool allowed_stroke(const SkStrokeRec& stroke) {
	SkASSERT(stroke.getStyle() == SkStrokeRec::kStroke_Style \|\|
	stroke.getStyle() == SkStrokeRec::kHairline_Style);
	return !stroke.getWidth() \|\|
	(stroke.getJoin() == SkPaint::kMiter_Join && stroke.getMiter() > SK_ScalarSqrt2);
	}

	namespace {

	class NonAAStrokeRectOp final : public GrMeshDrawOp {
	private:
	using Helper = GrSimpleMeshDrawOpHelper;

	public:
	DEFINE_OP_CLASS_ID

	const char* name() const override { return "NonAAStrokeRectOp"; }

	void visitProxies(const VisitProxyFunc& func) const override {
	fHelper.visitProxies(func);
	}

	SkString dumpInfo() const override {
	SkString string;
	string.appendf(
	"Color: 0x%08x, Rect [L: %.2f, T: %.2f, R: %.2f, B: %.2f], "
	"StrokeWidth: %.2f\n",
	fColor, fRect.fLeft, fRect.fTop, fRect.fRight, fRect.fBottom, fStrokeWidth);
	string += fHelper.dumpInfo();
	string += INHERITED::dumpInfo();
	return string;
	}

	static std::unique_ptr<GrDrawOp> Make(GrContext* context,
	GrPaint&& paint,
	const SkMatrix& viewMatrix,
	const SkRect& rect,
	const SkStrokeRec& stroke,
	GrAAType aaType) {
	if (!allowed_stroke(stroke)) {
	return nullptr;
	}
	Helper::Flags flags = Helper::Flags::kNone;
	// Depending on sub-pixel coordinates and the particular GPU, we may lose a corner of
	// hairline rects. We jam all the vertices to pixel centers to avoid this, but not
	// when MSAA is enabled because it can cause ugly artifacts.
	if (stroke.getStyle() == SkStrokeRec::kHairline_Style && aaType != GrAAType::kMSAA) {
	flags \|= Helper::Flags::kSnapVerticesToPixelCenters;
	}
	return Helper::FactoryHelper<NonAAStrokeRectOp>(context, std::move(paint), flags,
	viewMatrix, rect,
	stroke, aaType);
	}

	NonAAStrokeRectOp(const Helper::MakeArgs& helperArgs, GrColor color, Helper::Flags flags,
	const SkMatrix& viewMatrix, const SkRect& rect, const SkStrokeRec& stroke,
	GrAAType aaType)
	: INHERITED(ClassID()), fHelper(helperArgs, aaType, flags) {
	fColor = color;
	fViewMatrix = viewMatrix;
	fRect = rect;
	// Sort the rect for hairlines
	fRect.sort();
	fStrokeWidth = stroke.getWidth();

	SkScalar rad = SkScalarHalf(fStrokeWidth);
	SkRect bounds = rect;
	bounds.outset(rad, rad);

	// If our caller snaps to pixel centers then we have to round out the bounds
	if (flags & Helper::Flags::kSnapVerticesToPixelCenters) {
	viewMatrix.mapRect(&bounds);
	// We want to be consistent with how we snap non-aa lines. To match what we do in
	// GrGLSLVertexShaderBuilder, we first floor all the vertex values and then add half a
	// pixel to force us to pixel centers.
	bounds.set(SkScalarFloorToScalar(bounds.fLeft),
	SkScalarFloorToScalar(bounds.fTop),
	SkScalarFloorToScalar(bounds.fRight),
	SkScalarFloorToScalar(bounds.fBottom));
	bounds.offset(0.5f, 0.5f);
	this->setBounds(bounds, HasAABloat::kNo, IsZeroArea::kNo);
	} else {
	this->setTransformedBounds(bounds, fViewMatrix, HasAABloat::kNo, IsZeroArea::kNo);
	}
	}

	FixedFunctionFlags fixedFunctionFlags() const override { return fHelper.fixedFunctionFlags(); }

	RequiresDstTexture finalize(const GrCaps& caps, const GrAppliedClip* clip,
	GrPixelConfigIsClamped dstIsClamped) override {
	return fHelper.xpRequiresDstTexture(caps, clip, dstIsClamped,
	GrProcessorAnalysisCoverage::kNone, &fColor);
	}

	private:
	void onPrepareDraws(Target* target) override {
	sk_sp<GrGeometryProcessor> gp;
	{
	using namespace GrDefaultGeoProcFactory;
	Color color(fColor);
	LocalCoords::Type localCoordsType = fHelper.usesLocalCoords()
	? LocalCoords::kUsePosition_Type
	: LocalCoords::kUnused_Type;
	gp = GrDefaultGeoProcFactory::Make(color, Coverage::kSolid_Type, localCoordsType,
	fViewMatrix);
	}

	static constexpr size_t kVertexStride = sizeof(GrDefaultGeoProcFactory::PositionAttr);

	SkASSERT(kVertexStride == gp->debugOnly_vertexStride());

	int vertexCount = kVertsPerHairlineRect;
	if (fStrokeWidth > 0) {
	vertexCount = kVertsPerStrokeRect;
	}

	const GrBuffer* vertexBuffer;
	int firstVertex;

	void* verts =
	target->makeVertexSpace(kVertexStride, vertexCount, &vertexBuffer, &firstVertex);

	if (!verts) {
	SkDebugf("Could not allocate vertices\n");
	return;
	}

	SkPoint* vertex = reinterpret_cast<SkPoint*>(verts);

	GrPrimitiveType primType;
	if (fStrokeWidth > 0) {
	primType = GrPrimitiveType::kTriangleStrip;
	init_stroke_rect_strip(vertex, fRect, fStrokeWidth);
	} else {
	// hairline
	primType = GrPrimitiveType::kLineStrip;
	vertex[0].set(fRect.fLeft, fRect.fTop);
	vertex[1].set(fRect.fRight, fRect.fTop);
	vertex[2].set(fRect.fRight, fRect.fBottom);
	vertex[3].set(fRect.fLeft, fRect.fBottom);
	vertex[4].set(fRect.fLeft, fRect.fTop);
	}

	GrMesh mesh(primType);
	mesh.setNonIndexedNonInstanced(vertexCount);
	mesh.setVertexData(vertexBuffer, firstVertex);
	target->draw(gp.get(), fHelper.makePipeline(target), mesh);
	}

	bool onCombineIfPossible(GrOp* t, const GrCaps&) override {
	// NonAA stroke rects cannot combine right now
	// TODO make these combinable.
	return false;
	}

	Helper fHelper;
	GrColor fColor;
	SkMatrix fViewMatrix;
	SkRect fRect;
	SkScalar fStrokeWidth;

	const static int kVertsPerHairlineRect = 5;
	const static int kVertsPerStrokeRect = 10;

	typedef GrMeshDrawOp INHERITED;
	};

	} // anonymous namespace

	namespace GrRectOpFactory {
	std::unique_ptr<GrDrawOp> MakeNonAAStroke(GrContext* context,
	GrPaint&& paint,
	const SkMatrix& viewMatrix,
	const SkRect& rect,
	const SkStrokeRec& stroke,
	GrAAType aaType) {
	return NonAAStrokeRectOp::Make(context, std::move(paint), viewMatrix, rect, stroke, aaType);
	}
	} // namespace GrRectOpFactory

	#if GR_TEST_UTILS

	GR_DRAW_OP_TEST_DEFINE(NonAAStrokeRectOp) {
	SkMatrix viewMatrix = GrTest::TestMatrix(random);
	SkRect rect = GrTest::TestRect(random);
	SkScalar strokeWidth = random->nextBool() ? 0.0f : 2.0f;
	SkPaint strokePaint;
	strokePaint.setStrokeWidth(strokeWidth);
	strokePaint.setStyle(SkPaint::kStroke_Style);
	strokePaint.setStrokeJoin(SkPaint::kMiter_Join);
	SkStrokeRec strokeRec(strokePaint);
	GrAAType aaType = GrAAType::kNone;
	if (fsaaType == GrFSAAType::kUnifiedMSAA) {
	aaType = random->nextBool() ? GrAAType::kMSAA : GrAAType::kNone;
	}
	return NonAAStrokeRectOp::Make(context, std::move(paint), viewMatrix, rect, strokeRec, aaType);
	}

	#endif