Introduce dynamic pipeline state

Adds a DynamicState struct to GrPipeline that has a field for the
scissor rect. Eventually this should become the only way to specify a
scissor rectangle and may grow to contain more fields. Adds an array of
DynamicStates to GrGpuCommandBuffer::draw and implements support in GL
and Vulkan.

Bug: skia:
Change-Id: If5aebbf9da5d192acf7e68e7def4674ffc7ec310
Reviewed-on: https://skia-review.googlesource.com/18510
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>

3 files changed, 227 insertions, 10 deletions

diff --git a/tests/GpuSampleLocationsTest.cpp b/tests/GpuSampleLocationsTest.cpp
index 75d2846dd6..aaab98adda 100644
--- a/tests/GpuSampleLocationsTest.cpp
+++ b/tests/GpuSampleLocationsTest.cpp
@@ -91,10 +91,6 @@ public:
     virtual ~TestSampleLocationsInterface() {}
 };
 
-static sk_sp<GrPipeline> construct_dummy_pipeline(GrRenderTargetContext* dc) {
-    return sk_sp<GrPipeline>(new GrPipeline(dc->accessRenderTarget(), SkBlendMode::kSrcOver));
-}
-
 void assert_equal(skiatest::Reporter* reporter, const SamplePattern& pattern,
                   const GrGpu::MultisampleSpecs& specs, bool flipY) {
     GrAlwaysAssert(specs.fSampleLocations);
@@ -136,11 +132,13 @@ void test_sampleLocations(skiatest::Reporter* reporter, TestSampleLocationsInter
     for (int repeat = 0; repeat < 2; ++repeat) {
         for (int i = 0; i < numTestPatterns; ++i) {
             testInterface->overrideSamplePattern(kTestPatterns[i]);
-            for (GrRenderTargetContext* dc : {bottomUps[i].get(), topDowns[i].get()}) {
-                sk_sp<GrPipeline> dummyPipeline = construct_dummy_pipeline(dc);
-                GrRenderTarget* rt = dc->accessRenderTarget();
+            for (GrRenderTargetContext* rtc : {bottomUps[i].get(), topDowns[i].get()}) {
+                GrPipeline dummyPipeline(rtc->accessRenderTarget(),
+                                         GrPipeline::ScissorState::kDisabled,
+                                         SkBlendMode::kSrcOver);
+                GrRenderTarget* rt = rtc->accessRenderTarget();
                 assert_equal(reporter, kTestPatterns[i],
-                             rt->renderTargetPriv().getMultisampleSpecs(*dummyPipeline),
+                             rt->renderTargetPriv().getMultisampleSpecs(dummyPipeline),
                              kBottomLeft_GrSurfaceOrigin == rt->origin());
             }
         }
diff --git a/tests/GrMeshTest.cpp b/tests/GrMeshTest.cpp
index 3a2be784a5..dd2a2d9e33 100644
--- a/tests/GrMeshTest.cpp
+++ b/tests/GrMeshTest.cpp
@@ -364,9 +364,9 @@ sk_sp<const GrBuffer> DrawMeshHelper::getIndexBuffer() {
 
 void DrawMeshHelper::drawMesh(const GrMesh& mesh) {
     GrRenderTarget* rt = fState->drawOpArgs().fRenderTarget;
-    GrPipeline pipeline(rt, SkBlendMode::kSrc);
+    GrPipeline pipeline(rt, GrPipeline::ScissorState::kDisabled, SkBlendMode::kSrc);
     GrMeshTestProcessor mtp(mesh.isInstanced(), mesh.hasVertexData());
-    fState->commandBuffer()->draw(pipeline, mtp, &mesh, 1,
+    fState->commandBuffer()->draw(pipeline, mtp, &mesh, nullptr, 1,
                                   SkRect::MakeIWH(kImageWidth, kImageHeight));
 }
 
diff --git a/tests/GrPipelineDynamicStateTest.cpp b/tests/GrPipelineDynamicStateTest.cpp
new file mode 100644
index 0000000000..4c5843aeb1
--- /dev/null
+++ b/tests/GrPipelineDynamicStateTest.cpp
@@ -0,0 +1,219 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkTypes.h"
+#include "Test.h"
+
+#if SK_SUPPORT_GPU
+
+#include "GrContext.h"
+#include "GrColor.h"
+#include "GrGeometryProcessor.h"
+#include "GrOpFlushState.h"
+#include "GrRenderTargetContext.h"
+#include "GrRenderTargetContextPriv.h"
+#include "GrResourceProvider.h"
+#include "SkMakeUnique.h"
+#include "glsl/GrGLSLVertexShaderBuilder.h"
+#include "glsl/GrGLSLFragmentShaderBuilder.h"
+#include "glsl/GrGLSLGeometryProcessor.h"
+#include "glsl/GrGLSLVarying.h"
+
+/**
+ * This is a GPU-backend specific test for dynamic pipeline state. It draws boxes using dynamic
+ * scissor rectangles then reads back the result to verify a successful test.
+ */
+
+using ScissorState = GrPipeline::ScissorState;
+
+static constexpr int kScreenSize = 6;
+static constexpr int kNumMeshes = 4;
+static constexpr int kScreenSplitX = kScreenSize/2;
+static constexpr int kScreenSplitY = kScreenSize/2;
+
+static const GrPipeline::DynamicState kDynamicStates[kNumMeshes] = {
+    {SkIRect::MakeLTRB(0,              0,              kScreenSplitX,  kScreenSplitY)},
+    {SkIRect::MakeLTRB(0,              kScreenSplitY,  kScreenSplitX,  kScreenSize)},
+    {SkIRect::MakeLTRB(kScreenSplitX,  0,              kScreenSize,    kScreenSplitY)},
+    {SkIRect::MakeLTRB(kScreenSplitX,  kScreenSplitY,  kScreenSize,    kScreenSize)},
+};
+
+static const GrColor kMeshColors[kNumMeshes] {
+    GrColorPackRGBA(255, 0, 0, 255),
+    GrColorPackRGBA(0, 255, 0, 255),
+    GrColorPackRGBA(0, 0, 255, 255),
+    GrColorPackRGBA(0, 0, 0, 255)
+};
+
+struct Vertex {
+    float     fX;
+    float     fY;
+    GrColor   fColor;
+};
+
+class GrPipelineDynamicStateTestProcessor : public GrGeometryProcessor {
+public:
+    GrPipelineDynamicStateTestProcessor()
+        : fVertex(this->addVertexAttrib("vertex", kVec2f_GrVertexAttribType))
+        , fColor(this->addVertexAttrib("color", kVec4ub_GrVertexAttribType)) {
+        this->initClassID<GrPipelineDynamicStateTestProcessor>();
+    }
+
+    const char* name() const override { return "GrPipelineDynamicStateTest Processor"; }
+
+    void getGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const final {}
+
+    GrGLSLPrimitiveProcessor* createGLSLInstance(const GrShaderCaps&) const final;
+
+protected:
+    const Attribute& fVertex;
+    const Attribute& fColor;
+
+    friend class GLSLPipelineDynamicStateTestProcessor;
+    typedef GrGeometryProcessor INHERITED;
+};
+
+class GLSLPipelineDynamicStateTestProcessor : public GrGLSLGeometryProcessor {
+    void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor&,
+                 FPCoordTransformIter&& transformIter) final {}
+
+    void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) final {
+        const GrPipelineDynamicStateTestProcessor& mp =
+            args.fGP.cast<GrPipelineDynamicStateTestProcessor>();
+
+        GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
+        varyingHandler->emitAttributes(mp);
+        varyingHandler->addPassThroughAttribute(&mp.fColor, args.fOutputColor);
+
+        GrGLSLVertexBuilder* v = args.fVertBuilder;
+        v->codeAppendf("vec2 vertex = %s;", mp.fVertex.fName);
+        gpArgs->fPositionVar.set(kVec2f_GrSLType, "vertex");
+
+        GrGLSLPPFragmentBuilder* f = args.fFragBuilder;
+        f->codeAppendf("%s = vec4(1);", args.fOutputCoverage);
+    }
+};
+
+GrGLSLPrimitiveProcessor*
+GrPipelineDynamicStateTestProcessor::createGLSLInstance(const GrShaderCaps&) const {
+    return new GLSLPipelineDynamicStateTestProcessor;
+}
+
+class GrPipelineDynamicStateTestOp : public GrDrawOp {
+public:
+    DEFINE_OP_CLASS_ID
+
+    GrPipelineDynamicStateTestOp(ScissorState scissorState, sk_sp<const GrBuffer> vbuff)
+        : INHERITED(ClassID())
+        , fScissorState(scissorState)
+        , fVertexBuffer(std::move(vbuff)) {
+        this->setBounds(SkRect::MakeIWH(kScreenSize, kScreenSize),
+                        HasAABloat::kNo, IsZeroArea::kNo);
+    }
+
+private:
+    const char* name() const override { return "GrPipelineDynamicStateTestOp"; }
+    FixedFunctionFlags fixedFunctionFlags() const override { return FixedFunctionFlags::kNone; }
+    bool xpRequiresDstTexture(const GrCaps&, const GrAppliedClip*) override { return false; }
+    bool onCombineIfPossible(GrOp* other, const GrCaps& caps) override { return false; }
+    void onPrepare(GrOpFlushState*) override {}
+    void onExecute(GrOpFlushState* state) override {
+        GrRenderTarget* rt = state->drawOpArgs().fRenderTarget;
+        GrPipeline pipeline(rt, fScissorState, SkBlendMode::kSrc);
+        SkSTArray<kNumMeshes, GrMesh> meshes;
+        for (int i = 0; i < kNumMeshes; ++i) {
+            GrMesh& mesh = meshes.emplace_back(kTriangleStrip_GrPrimitiveType);
+            mesh.setNonIndexedNonInstanced(4);
+            mesh.setVertexData(fVertexBuffer.get(), 4 * i);
+        }
+        state->commandBuffer()->draw(pipeline, GrPipelineDynamicStateTestProcessor(),
+                                     meshes.begin(), kDynamicStates, 4,
+                                     SkRect::MakeIWH(kScreenSize, kScreenSize));
+    }
+
+    ScissorState                fScissorState;
+    const sk_sp<const GrBuffer> fVertexBuffer;
+
+    typedef GrDrawOp INHERITED;
+};
+
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(GrPipelineDynamicStateTest, reporter, ctxInfo) {
+    GrContext* const context = ctxInfo.grContext();
+    GrResourceProvider* rp = context->resourceProvider();
+
+    sk_sp<GrRenderTargetContext> rtc(
+        context->makeDeferredRenderTargetContext(SkBackingFit::kExact, kScreenSize, kScreenSize,
+                                                 kRGBA_8888_GrPixelConfig, nullptr));
+    if (!rtc) {
+        ERRORF(reporter, "could not create render target context.");
+        return;
+    }
+
+    constexpr float d = (float) kScreenSize;
+    Vertex vdata[kNumMeshes * 4] = {
+        {0, 0, kMeshColors[0]},
+        {0, d, kMeshColors[0]},
+        {d, 0, kMeshColors[0]},
+        {d, d, kMeshColors[0]},
+
+        {0, 0, kMeshColors[1]},
+        {0, d, kMeshColors[1]},
+        {d, 0, kMeshColors[1]},
+        {d, d, kMeshColors[1]},
+
+        {0, 0, kMeshColors[2]},
+        {0, d, kMeshColors[2]},
+        {d, 0, kMeshColors[2]},
+        {d, d, kMeshColors[2]},
+
+        {0, 0, kMeshColors[3]},
+        {0, d, kMeshColors[3]},
+        {d, 0, kMeshColors[3]},
+        {d, d, kMeshColors[3]}
+    };
+
+    sk_sp<const GrBuffer> vbuff(rp->createBuffer(sizeof(vdata), kVertex_GrBufferType,
+                                                 kDynamic_GrAccessPattern,
+                                                 GrResourceProvider::kNoPendingIO_Flag |
+                                                 GrResourceProvider::kRequireGpuMemory_Flag,
+                                                 vdata));
+    if (!vbuff) {
+        ERRORF(reporter, "vbuff is null.");
+        return;
+    }
+
+    uint32_t resultPx[kScreenSize * kScreenSize];
+
+    for (ScissorState scissorState : {ScissorState::kEnabled, ScissorState::kDisabled}) {
+        rtc->clear(nullptr, 0xbaaaaaad, true);
+        rtc->priv().testingOnly_addDrawOp(
+            skstd::make_unique<GrPipelineDynamicStateTestOp>(scissorState, vbuff));
+        rtc->readPixels(SkImageInfo::Make(kScreenSize, kScreenSize,
+                                          kRGBA_8888_SkColorType, kPremul_SkAlphaType),
+                        resultPx, 4 * kScreenSize, 0, 0, 0);
+        for (int y = 0; y < kScreenSize; ++y) {
+            for (int x = 0; x < kScreenSize; ++x) {
+                int expectedColorIdx;
+                if (ScissorState::kEnabled == scissorState) {
+                    expectedColorIdx = (x < kScreenSplitX ? 0 : 2) + (y < kScreenSplitY ? 0 : 1);
+                } else {
+                    expectedColorIdx = kNumMeshes - 1;
+                }
+                uint32_t expected = kMeshColors[expectedColorIdx];
+                uint32_t actual = resultPx[y * kScreenSize + x];
+                if (expected != actual) {
+                    ERRORF(reporter, "[scissor=%s] pixel (%i,%i): got 0x%x expected 0x%x",
+                           ScissorState::kEnabled == scissorState ? "enabled" : "disabled", x, y,
+                           actual, expected);
+                    return;
+                }
+            }
+        }
+    }
+}
+
+#endif