1 files changed, 194 insertions, 0 deletions
diff --git a/src/effects/gradients/Sk4fGradientPriv.h b/src/effects/gradients/Sk4fGradientPriv.h
new file mode 100644
index 0000000000..b8f4bcaee1
--- /dev/null
+++ b/src/effects/gradients/Sk4fGradientPriv.h
@@ -0,0 +1,194 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef Sk4fGradientPriv_DEFINED
+#define Sk4fGradientPriv_DEFINED
+
+#include "SkColor.h"
+#include "SkHalf.h"
+#include "SkImageInfo.h"
+#include "SkNx.h"
+#include "SkPM4f.h"
+#include "SkPM4fPriv.h"
+#include "SkUtils.h"
+
+// Templates shared by various 4f gradient flavors.
+
+namespace {
+
+enum class ApplyPremul { True, False };
+
+enum class DstType {
+    L32,  // Linear 32bit.  Used for both shader/blitter paths.
+    S32,  // SRGB 32bit.  Used for the blitter path only.
+    F16,  // Linear half-float.  Used for blitters only.
+    F32,  // Linear float.  Used for shaders only.
+};
+
+template <ApplyPremul>
+struct PremulTraits;
+
+template <>
+struct PremulTraits<ApplyPremul::False> {
+    static Sk4f apply(const Sk4f& c) { return c; }
+};
+
+template <>
+struct PremulTraits<ApplyPremul::True> {
+    static Sk4f apply(const Sk4f& c) {
+        const float alpha = c[SkPM4f::A];
+        // FIXME: portable swizzle?
+        return c * Sk4f(alpha, alpha, alpha, 1);
+    }
+};
+
+// Struct encapsulating various dest-dependent ops:
+//
+//   - load()       Load a SkPM4f value into Sk4f.  Normally called once per interval
+//                  advance.  Also applies a scale and swizzle suitable for DstType.
+//
+//   - store()      Store one Sk4f to dest.  Optionally handles premul, color space
+//                  conversion, etc.
+//
+//   - store(count) Store the Sk4f value repeatedly to dest, count times.
+//
+//   - store4x()    Store 4 Sk4f values to dest (opportunistic optimization).
+//
+template <DstType, ApplyPremul premul>
+struct DstTraits;
+
+template <ApplyPremul premul>
+struct DstTraits<DstType::L32, premul> {
+    using PM   = PremulTraits<premul>;
+    using Type = SkPMColor;
+
+    // For L32, prescaling by 255 saves a per-pixel multiplication when premul is not needed.
+    static Sk4f load(const SkPM4f& c) {
+        return premul == ApplyPremul::False
+            ? c.to4f_pmorder() * Sk4f(255)
+            : c.to4f_pmorder();
+    }
+
+    static void store(const Sk4f& c, Type* dst) {
+        if (premul == ApplyPremul::False) {
+            // c is prescaled by 255, just store.
+            SkNx_cast<uint8_t>(c).store(dst);
+        } else {
+            *dst = Sk4f_toL32(PM::apply(c));
+        }
+    }
+
+    static void store(const Sk4f& c, Type* dst, int n) {
+        Type pmc;
+        store(c, &pmc);
+        sk_memset32(dst, pmc, n);
+    }
+
+    static void store4x(const Sk4f& c0, const Sk4f& c1,
+                        const Sk4f& c2, const Sk4f& c3,
+                        Type* dst) {
+        if (premul == ApplyPremul::False) {
+            Sk4f_ToBytes((uint8_t*)dst, c0, c1, c2, c3);
+        } else {
+            store(c0, dst + 0);
+            store(c1, dst + 1);
+            store(c2, dst + 2);
+            store(c3, dst + 3);
+        }
+    }
+};
+
+template <ApplyPremul premul>
+struct DstTraits<DstType::S32, premul> {
+    using PM   = PremulTraits<premul>;
+    using Type = SkPMColor;
+
+    static Sk4f load(const SkPM4f& c) {
+        return c.to4f_pmorder();
+    }
+
+    static void store(const Sk4f& c, Type* dst) {
+        // FIXME: this assumes opaque colors.  Handle unpremultiplication.
+        *dst = Sk4f_toS32(PM::apply(c));
+    }
+
+    static void store(const Sk4f& c, Type* dst, int n) {
+        sk_memset32(dst, Sk4f_toS32(PM::apply(c)), n);
+    }
+
+    static void store4x(const Sk4f& c0, const Sk4f& c1,
+                        const Sk4f& c2, const Sk4f& c3,
+                        Type* dst) {
+        store(c0, dst + 0);
+        store(c1, dst + 1);
+        store(c2, dst + 2);
+        store(c3, dst + 3);
+    }
+};
+
+template <ApplyPremul premul>
+struct DstTraits<DstType::F16, premul> {
+    using PM   = PremulTraits<premul>;
+    using Type = uint64_t;
+
+    static Sk4f load(const SkPM4f& c) {
+        return c.to4f();
+    }
+
+    static void store(const Sk4f& c, Type* dst) {
+        SkFloatToHalf_finite_ftz(PM::apply(c)).store(dst);
+    }
+
+    static void store(const Sk4f& c, Type* dst, int n) {
+        uint64_t color;
+        SkFloatToHalf_finite_ftz(PM::apply(c)).store(&color);
+        sk_memset64(dst, color, n);
+    }
+
+    static void store4x(const Sk4f& c0, const Sk4f& c1,
+                        const Sk4f& c2, const Sk4f& c3,
+                        Type* dst) {
+        store(c0, dst + 0);
+        store(c1, dst + 1);
+        store(c2, dst + 2);
+        store(c3, dst + 3);
+    }
+};
+
+template <ApplyPremul premul>
+struct DstTraits<DstType::F32, premul> {
+    using PM   = PremulTraits<premul>;
+    using Type = SkPM4f;
+
+    static Sk4f load(const SkPM4f& c) {
+        return c.to4f();
+    }
+
+    static void store(const Sk4f& c, Type* dst) {
+        PM::apply(c).store(dst->fVec);
+    }
+
+    static void store(const Sk4f& c, Type* dst, int n) {
+        const Sk4f pmc = PM::apply(c);
+        for (int i = 0; i < n; ++i) {
+            pmc.store(dst[i].fVec);
+        }
+    }
+
+    static void store4x(const Sk4f& c0, const Sk4f& c1,
+                        const Sk4f& c2, const Sk4f& c3,
+                        Type* dst) {
+        store(c0, dst + 0);
+        store(c1, dst + 1);
+        store(c2, dst + 2);
+        store(c3, dst + 3);
+    }
+};
+
+} // anonymous namespace
+
+#endif // Sk4fGradientPriv_DEFINED