move SkMask.h to src

Bug: skia:
Change-Id: Ie51476412fb52df7cc07fdbd4dbbbfc89d9c08a7
Reviewed-on: https://skia-review.googlesource.com/104081
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>

1 files changed, 154 insertions, 0 deletions

diff --git a/src/core/SkMask.h b/src/core/SkMask.h
new file mode 100644
index 0000000000..d4c5e3599c
--- /dev/null
+++ b/src/core/SkMask.h
@@ -0,0 +1,154 @@
+
+/*
+ * Copyright 2006 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#ifndef SkMask_DEFINED
+#define SkMask_DEFINED
+
+#include "SkRect.h"
+
+/** \class SkMask
+    SkMask is used to describe alpha bitmaps, either 1bit, 8bit, or
+    the 3-channel 3D format. These are passed to SkMaskFilter objects.
+*/
+struct SkMask {
+    SkMask() : fImage(nullptr) {}
+
+    enum Format {
+        kBW_Format, //!< 1bit per pixel mask (e.g. monochrome)
+        kA8_Format, //!< 8bits per pixel mask (e.g. antialiasing)
+        k3D_Format, //!< 3 8bit per pixl planes: alpha, mul, add
+        kARGB32_Format,         //!< SkPMColor
+        kLCD16_Format,          //!< 565 alpha for r/g/b
+    };
+
+    enum {
+        kCountMaskFormats = kLCD16_Format + 1
+    };
+
+    uint8_t*    fImage;
+    SkIRect     fBounds;
+    uint32_t    fRowBytes;
+    Format      fFormat;
+
+    /** Returns true if the mask is empty: i.e. it has an empty bounds.
+     */
+    bool isEmpty() const { return fBounds.isEmpty(); }
+
+    /** Return the byte size of the mask, assuming only 1 plane.
+        Does not account for k3D_Format. For that, use computeTotalImageSize().
+        If there is an overflow of 32bits, then returns 0.
+    */
+    size_t computeImageSize() const;
+
+    /** Return the byte size of the mask, taking into account
+        any extra planes (e.g. k3D_Format).
+        If there is an overflow of 32bits, then returns 0.
+    */
+    size_t computeTotalImageSize() const;
+
+    /** Returns the address of the byte that holds the specified bit.
+        Asserts that the mask is kBW_Format, and that x,y are in range.
+        x,y are in the same coordiate space as fBounds.
+    */
+    uint8_t* getAddr1(int x, int y) const {
+        SkASSERT(kBW_Format == fFormat);
+        SkASSERT(fBounds.contains(x, y));
+        SkASSERT(fImage != nullptr);
+        return fImage + ((x - fBounds.fLeft) >> 3) + (y - fBounds.fTop) * fRowBytes;
+    }
+
+    /** Returns the address of the specified byte.
+        Asserts that the mask is kA8_Format, and that x,y are in range.
+        x,y are in the same coordiate space as fBounds.
+    */
+    uint8_t* getAddr8(int x, int y) const {
+        SkASSERT(kA8_Format == fFormat);
+        SkASSERT(fBounds.contains(x, y));
+        SkASSERT(fImage != nullptr);
+        return fImage + x - fBounds.fLeft + (y - fBounds.fTop) * fRowBytes;
+    }
+
+    /**
+     *  Return the address of the specified 16bit mask. In the debug build,
+     *  this asserts that the mask's format is kLCD16_Format, and that (x,y)
+     *  are contained in the mask's fBounds.
+     */
+    uint16_t* getAddrLCD16(int x, int y) const {
+        SkASSERT(kLCD16_Format == fFormat);
+        SkASSERT(fBounds.contains(x, y));
+        SkASSERT(fImage != nullptr);
+        uint16_t* row = (uint16_t*)(fImage + (y - fBounds.fTop) * fRowBytes);
+        return row + (x - fBounds.fLeft);
+    }
+
+    /**
+     *  Return the address of the specified 32bit mask. In the debug build,
+     *  this asserts that the mask's format is 32bits, and that (x,y)
+     *  are contained in the mask's fBounds.
+     */
+    uint32_t* getAddr32(int x, int y) const {
+        SkASSERT(kARGB32_Format == fFormat);
+        SkASSERT(fBounds.contains(x, y));
+        SkASSERT(fImage != nullptr);
+        uint32_t* row = (uint32_t*)(fImage + (y - fBounds.fTop) * fRowBytes);
+        return row + (x - fBounds.fLeft);
+    }
+
+    /**
+     *  Returns the address of the specified pixel, computing the pixel-size
+     *  at runtime based on the mask format. This will be slightly slower than
+     *  using one of the routines where the format is implied by the name
+     *  e.g. getAddr8 or getAddr32.
+     *
+     *  x,y must be contained by the mask's bounds (this is asserted in the
+     *  debug build, but not checked in the release build.)
+     *
+     *  This should not be called with kBW_Format, as it will give unspecified
+     *  results (and assert in the debug build).
+     */
+    void* getAddr(int x, int y) const;
+
+    enum AllocType {
+        kUninit_Alloc,
+        kZeroInit_Alloc,
+    };
+    static uint8_t* AllocImage(size_t bytes, AllocType = kUninit_Alloc);
+    static void FreeImage(void* image);
+
+    enum CreateMode {
+        kJustComputeBounds_CreateMode,      //!< compute bounds and return
+        kJustRenderImage_CreateMode,        //!< render into preallocate mask
+        kComputeBoundsAndRenderImage_CreateMode  //!< compute bounds, alloc image and render into it
+    };
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+/**
+ *  \class SkAutoMaskImage
+ *
+ *  Stack class used to manage the fImage buffer in a SkMask.
+ *  When this object loses scope, the buffer is freed with SkMask::FreeImage().
+ */
+class SkAutoMaskFreeImage {
+public:
+    SkAutoMaskFreeImage(uint8_t* maskImage) {
+        fImage = maskImage;
+    }
+
+    ~SkAutoMaskFreeImage() {
+        SkMask::FreeImage(fImage);
+    }
+
+private:
+    uint8_t* fImage;
+};
+#define SkAutoMaskFreeImage(...) SK_REQUIRE_LOCAL_VAR(SkAutoMaskFreeImage)
+
+#endif