skia WIPjarred/canvas

1 files changed, 116 insertions, 0 deletions

diff --git a/src/deps/skia/include/sksl/DSLFunction.h b/src/deps/skia/include/sksl/DSLFunction.h
new file mode 100644
index 000000000..aa40bdfb6
--- /dev/null
+++ b/src/deps/skia/include/sksl/DSLFunction.h
@@ -0,0 +1,116 @@
+/*
+ * Copyright 2021 Google LLC.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SKSL_DSL_FUNCTION
+#define SKSL_DSL_FUNCTION
+
+#include "include/sksl/DSLBlock.h"
+#include "include/sksl/DSLExpression.h"
+#include "include/sksl/DSLType.h"
+#include "include/sksl/DSLVar.h"
+#include "include/sksl/DSLWrapper.h"
+
+namespace SkSL {
+
+class Block;
+class FunctionDeclaration;
+class Variable;
+
+namespace dsl {
+
+class DSLType;
+
+class DSLFunction {
+public:
+    template<class... Parameters>
+    DSLFunction(const DSLType& returnType, skstd::string_view name, Parameters&... parameters)
+        : DSLFunction(DSLModifiers(), returnType, name, parameters...) {}
+
+    template<class... Parameters>
+    DSLFunction(const DSLModifiers& modifiers, const DSLType& returnType, skstd::string_view name,
+                Parameters&... parameters) {
+        SkTArray<DSLParameter*> parameterArray;
+        parameterArray.reserve_back(sizeof...(parameters));
+
+        // in C++17, we could just do:
+        // (parameterArray.push_back(&parameters), ...);
+        int unused[] = {0, (static_cast<void>(parameterArray.push_back(&parameters)), 0)...};
+        static_cast<void>(unused);
+        // We can't have a default parameter and a template parameter pack at the same time, so
+        // unfortunately we can't capture position info from this overload.
+        this->init(modifiers, returnType, name, std::move(parameterArray), PositionInfo());
+    }
+
+    DSLFunction(const DSLType& returnType, skstd::string_view name,
+                SkTArray<DSLParameter*> parameters, PositionInfo pos = PositionInfo::Capture()) {
+        this->init(DSLModifiers(), returnType, name, std::move(parameters), pos);
+    }
+
+    DSLFunction(const DSLModifiers& modifiers, const DSLType& returnType, skstd::string_view name,
+                SkTArray<DSLParameter*> parameters, PositionInfo pos = PositionInfo::Capture()) {
+        this->init(modifiers, returnType, name, std::move(parameters), pos);
+    }
+
+    DSLFunction(const SkSL::FunctionDeclaration* decl)
+        : fDecl(decl) {}
+
+    virtual ~DSLFunction() = default;
+
+    template<class... Stmt>
+    void define(Stmt... stmts) {
+        DSLBlock block = DSLBlock(DSLStatement(std::move(stmts))...);
+        this->define(std::move(block));
+    }
+
+    void define(DSLBlock block, PositionInfo pos = PositionInfo::Capture());
+
+    /**
+     * Invokes the function with the given arguments.
+     */
+    template<class... Args>
+    DSLExpression operator()(Args&&... args) {
+        ExpressionArray argArray;
+        argArray.reserve_back(sizeof...(args));
+        this->collectArgs(argArray, std::forward<Args>(args)...);
+        return this->call(std::move(argArray));
+    }
+
+    /**
+     * Invokes the function with the given arguments.
+     */
+    DSLExpression call(SkTArray<DSLWrapper<DSLExpression>> args,
+            PositionInfo pos = PositionInfo::Capture());
+
+    DSLExpression call(ExpressionArray args, PositionInfo pos = PositionInfo::Capture());
+
+private:
+    void collectArgs(ExpressionArray& args) {}
+
+    template<class... RemainingArgs>
+    void collectArgs(ExpressionArray& args, DSLVar& var, RemainingArgs&&... remaining) {
+        args.push_back(DSLExpression(var).release());
+        collectArgs(args, std::forward<RemainingArgs>(remaining)...);
+    }
+
+    template<class... RemainingArgs>
+    void collectArgs(ExpressionArray& args, DSLExpression expr, RemainingArgs&&... remaining) {
+        args.push_back(expr.release());
+        collectArgs(args, std::forward<RemainingArgs>(remaining)...);
+    }
+
+    void init(DSLModifiers modifiers, const DSLType& returnType, skstd::string_view name,
+              SkTArray<DSLParameter*> params, PositionInfo pos);
+
+    const SkSL::FunctionDeclaration* fDecl = nullptr;
+    SkSL::PositionInfo fPosition;
+};
+
+} // namespace dsl
+
+} // namespace SkSL
+
+#endif