[skotty,sksg] Initial gradient support
TBR=
Change-Id: I61e4d46ac14660f4c9ea757be2278e4098131a6b
Reviewed-on: https://skia-review.googlesource.com/94121
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
diff --git a/experimental/sksg/paint/SkSGGradient.cpp b/experimental/sksg/paint/SkSGGradient.cpp
new file mode 100644
index 0000000..98e7f39
--- /dev/null
+++ b/experimental/sksg/paint/SkSGGradient.cpp
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkSGGradient.h"
+
+#include "SkGradientShader.h"
+#include "SkPaint.h"
+
+namespace sksg {
+
+void Gradient::onApplyToPaint(SkPaint* paint) const {
+ if (fColorStops.empty()) {
+ paint->setShader(nullptr);
+ return;
+ }
+
+ std::vector<SkColor> colors;
+ std::vector<SkScalar> positions;
+ colors.reserve(fColorStops.size());
+ positions.reserve(fColorStops.size());
+
+ SkScalar position = 0;
+ for (const auto& stop : fColorStops) {
+ colors.push_back(stop.fColor);
+ position = SkTPin(stop.fPosition, position, 1.0f);
+ positions.push_back(position);
+ }
+
+ // TODO: detect even stop distributions, pass null for positions.
+ paint->setShader(this->onMakeShader(colors, positions));
+}
+
+sk_sp<SkShader> LinearGradient::onMakeShader(const std::vector<SkColor>& colors,
+ const std::vector<SkScalar>& positions) const {
+ SkASSERT(colors.size() == positions.size());
+
+ const SkPoint pts[] = { fStartPoint, fEndPoint };
+ return SkGradientShader::MakeLinear(pts, colors.data(), positions.data(), colors.size(),
+ this->getTileMode());
+}
+
+sk_sp<SkShader> RadialGradient::onMakeShader(const std::vector<SkColor>& colors,
+ const std::vector<SkScalar>& positions) const {
+ SkASSERT(colors.size() == positions.size());
+
+ return (fStartRadius <= 0 && fStartCenter == fEndCenter)
+ ? SkGradientShader::MakeRadial(fEndCenter, fEndRadius,
+ colors.data(), positions.data(), colors.size(),
+ this->getTileMode())
+ : SkGradientShader::MakeTwoPointConical(fStartCenter, fStartRadius,
+ fEndCenter, fEndRadius,
+ colors.data(), positions.data(), colors.size(),
+ this->getTileMode());
+}
+
+} //namespace sksg