[canvaskit] Add _RTShaderFactory for demos

Change-Id: Ib6dc1ff861efe4040508fea09c8a66d8d06db597
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/258568
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>

modules/canvaskit/canvaskit/extra.html

@@ -23,6 +23,10 @@
 <canvas id=sk_webfont width=500 height=500
         title='This shows loading of a custom font (e.g. WebFont)'></canvas>
 
+<h2> RT Shader </h2>
+<canvas id=rtshader width=300 height=300></canvas>
+
+
 <h2> Particles </h2>
 <canvas id=particles width=500 height=500></canvas>
 
@@ -68,6 +72,8 @@
     ParticlesAPI1(CanvasKit);
 
     ParagraphAPI1(CanvasKit, robotoData);
+
+    RTShaderAPI1(CanvasKit);
   });
 
   fetch('https://storage.googleapis.com/skia-cdn/misc/lego_loader.json').then((resp) => {
@@ -349,4 +355,38 @@ const curves = {
     document.getElementById('para1').addEventListener('pointermove', interact);
     return surface;
   }
+
+  function RTShaderAPI1(CanvasKit) {
+    if (!CanvasKit) {
+      return;
+    }
+    const prog = `
+
+  layout(ctype=SkRect) uniform half4 gColor;
+
+  void main(float x, float y, inout half4 color) {
+      color = half4(half(x)*(1.0/255), half(y)*(1.0/255), gColor.b, 1);
+  }
+`;
+    const surface = CanvasKit.MakeCanvasSurface('rtshader');
+    if (!surface) {
+      console.error('Could not make surface');
+      return;
+    }
+
+    const canvas = surface.getCanvas();
+
+    const fact = CanvasKit._RTShaderFactory.MakeFromProgram(prog, true);
+    const rot = CanvasKit.SkMatrix.rotated(90, 128, 128);
+    const shader = fact.make([1, 0, 0, 1], rot);
+
+    const paint = new CanvasKit.SkPaint();
+    paint.setShader(shader);
+    canvas.drawRect(CanvasKit.LTRBRect(0, 0, 256, 256), paint);
+
+    surface.flush();
+    shader.delete();
+    paint.delete();
+    fact.delete();
+  }
 </script>

modules/canvaskit/canvaskit_bindings.cpp

@@ -53,6 +53,7 @@
 #include "src/core/SkFontMgrPriv.h"
 #include "src/core/SkMakeUnique.h"
 #include "src/core/SkResourceCache.h"
+#include "src/shaders/SkRTShader.h"
 
 #include <iostream>
 #include <string>
@@ -1334,6 +1335,24 @@ EMSCRIPTEN_BINDINGS(Skia) {
     class_<SkShader>("SkShader")
         .smart_ptr<sk_sp<SkShader>>("sk_sp<SkShader>");
 
+    class_<SkRuntimeShaderFactory>("_RTShaderFactory")
+        .class_function("MakeFromProgram", optional_override([](std::string sksl, bool isOpaque)->SkRuntimeShaderFactory {
+            SkString s(sksl.c_str(), sksl.length());
+            return SkRuntimeShaderFactory(s, isOpaque);
+        }))
+        .function("_make", optional_override([](SkRuntimeShaderFactory& self, uintptr_t fptr, size_t len)->sk_sp<SkShader> {
+            uint8_t* floatData = reinterpret_cast<uint8_t*>(fptr);
+            sk_sp<SkData> bytes = SkData::MakeFromMalloc(floatData, len);
+            return self.make(bytes, nullptr);
+        }))
+        .function("_make", optional_override([](SkRuntimeShaderFactory& self, uintptr_t fptr, size_t len,
+                                                SimpleMatrix sm)->sk_sp<SkShader> {
+            uint8_t* floatData = reinterpret_cast<uint8_t*>(fptr);
+            sk_sp<SkData> bytes = SkData::MakeFromMalloc(floatData, len);
+            auto m = toSkMatrix(sm);
+            return self.make(bytes, &m);
+        }));
+
     class_<SkSurface>("SkSurface")
         .smart_ptr<sk_sp<SkSurface>>("sk_sp<SkSurface>")
         .function("_flush", select_overload<void()>(&SkSurface::flush))

modules/canvaskit/externs.js

@@ -124,6 +124,14 @@ var CanvasKit = {
 		_getRectsForRange: function() {},
 	},
 
+	_RTShaderFactory: {
+		// public API (from C++ bindings)
+		MakeFromProgram: function() {},
+
+		// private API
+		_make: function() {},
+	},
+
 	ParagraphStyle: function() {},
 	RSXFormBuilder: function() {},
 	SkColorBuilder: function() {},
@@ -784,6 +792,8 @@ CanvasKit.SkColorBuilder.prototype.delete = function() {};
 CanvasKit.SkColorBuilder.prototype.push = function() {};
 CanvasKit.SkColorBuilder.prototype.set = function() {};
 
+CanvasKit._RTShaderFactory.prototype.make = function() {};
+
 // Define StrokeOpts object
 var StrokeOpts = {};
 StrokeOpts.prototype.width;

modules/canvaskit/interface.js

@@ -216,6 +216,16 @@ CanvasKit.onRuntimeInitialized = function() {
     return m;
   }
 
+  CanvasKit._RTShaderFactory.prototype.make = function(floats, matrix) {
+    var fptr = copy1dArray(floats, CanvasKit.HEAPF32);
+    // Our array has 4 bytes per float, so be sure to account for that before
+    // sending it over the wire.
+    if (!matrix) {
+      return this._make(fptr, floats.length * 4);
+    }
+    return this._make(fptr, floats.length * 4, matrix);
+  }
+
   CanvasKit.SkPath.prototype.addArc = function(oval, startAngle, sweepAngle) {
     // see arc() for the HTMLCanvas version
     // note input angles are degrees.
@@ -1193,4 +1203,4 @@ CanvasKit.MakeSkVertices = function(mode, positions, textureCoordinates, colors,
   var idxCount = (indices && indices.length) || 0;
   // Create the vertices, which owns the memory that the builder had allocated.
   return builder.detach();
-};
+};

src/gpu/GrFragmentProcessor.h

@@ -530,8 +530,10 @@ public:
     operator bool() const { return !fFPStack.empty(); }
     bool operator!=(const EndIter&) { return (bool)*this; }
 
+    // Hopefully this does not actually get called because of RVO.
+    IterBase(const IterBase&) = default;
+
     // Because each iterator carries a stack we want to avoid copies.
-    IterBase(const IterBase&) = delete;
     IterBase& operator=(const IterBase&) = delete;
 
 protected: