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>

1 files changed, 13 insertions, 9 deletions

diff --git a/src/gpu/GrPipeline.cpp b/src/gpu/GrPipeline.cpp
index 8d1b926be1..9d8b2ef984 100644
--- a/src/gpu/GrPipeline.cpp
+++ b/src/gpu/GrPipeline.cpp
@@ -112,15 +112,19 @@ void GrPipeline::addDependenciesTo(GrRenderTargetProxy* rtp) const {
     }
 }
 
-GrPipeline::GrPipeline(GrRenderTarget* rt, SkBlendMode blendmode)
-        : fRenderTarget(rt)
-        , fScissorState()
-        , fWindowRectsState()
-        , fUserStencilSettings(&GrUserStencilSettings::kUnused)
-        , fFlags()
-        , fXferProcessor(GrPorterDuffXPFactory::MakeNoCoverageXP(blendmode))
-        , fFragmentProcessors()
-        , fNumColorProcessors(0) {}
+GrPipeline::GrPipeline(GrRenderTarget* rt, ScissorState scissorState, SkBlendMode blendmode)
+    : fRenderTarget(rt)
+    , fScissorState()
+    , fWindowRectsState()
+    , fUserStencilSettings(&GrUserStencilSettings::kUnused)
+    , fFlags()
+    , fXferProcessor(GrPorterDuffXPFactory::MakeNoCoverageXP(blendmode))
+    , fFragmentProcessors()
+    , fNumColorProcessors(0) {
+    if (ScissorState::kEnabled == scissorState) {
+        fScissorState.set({0, 0, 0, 0}); // caller will use the DynamicState struct.
+    }
+}
 
 ////////////////////////////////////////////////////////////////////////////////