1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/gpu/GrSWMaskHelper.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,107 @@
1.4 +/*
1.5 + * Copyright 2012 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef GrSWMaskHelper_DEFINED
1.12 +#define GrSWMaskHelper_DEFINED
1.13 +
1.14 +#include "GrColor.h"
1.15 +#include "GrDrawState.h"
1.16 +#include "SkBitmap.h"
1.17 +#include "SkDraw.h"
1.18 +#include "SkMatrix.h"
1.19 +#include "SkRasterClip.h"
1.20 +#include "SkRegion.h"
1.21 +#include "SkTypes.h"
1.22 +
1.23 +class GrAutoScratchTexture;
1.24 +class GrContext;
1.25 +class GrTexture;
1.26 +class SkPath;
1.27 +class SkStrokeRec;
1.28 +class GrDrawTarget;
1.29 +
1.30 +/**
1.31 + * The GrSWMaskHelper helps generate clip masks using the software rendering
1.32 + * path. It is intended to be used as:
1.33 + *
1.34 + * GrSWMaskHelper helper(context);
1.35 + * helper.init(...);
1.36 + *
1.37 + * draw one or more paths/rects specifying the required boolean ops
1.38 + *
1.39 + * toTexture(); // to get it from the internal bitmap to the GPU
1.40 + *
1.41 + * The result of this process will be the final mask (on the GPU) in the
1.42 + * upper left hand corner of the texture.
1.43 + */
1.44 +class GrSWMaskHelper : public SkNoncopyable {
1.45 +public:
1.46 + GrSWMaskHelper(GrContext* context)
1.47 + : fContext(context) {
1.48 + }
1.49 +
1.50 + // set up the internal state in preparation for draws. Since many masks
1.51 + // may be accumulated in the helper during creation, "resultBounds"
1.52 + // allows the caller to specify the region of interest - to limit the
1.53 + // amount of work.
1.54 + bool init(const SkIRect& resultBounds, const SkMatrix* matrix);
1.55 +
1.56 + // Draw a single rect into the accumulation bitmap using the specified op
1.57 + void draw(const SkRect& rect, SkRegion::Op op,
1.58 + bool antiAlias, uint8_t alpha);
1.59 +
1.60 + // Draw a single path into the accumuation bitmap using the specified op
1.61 + void draw(const SkPath& path, const SkStrokeRec& stroke, SkRegion::Op op,
1.62 + bool antiAlias, uint8_t alpha);
1.63 +
1.64 + // Helper function to get a scratch texture suitable for capturing the
1.65 + // result (i.e., right size & format)
1.66 + bool getTexture(GrAutoScratchTexture* texture);
1.67 +
1.68 + // Move the mask generation results from the internal bitmap to the gpu.
1.69 + void toTexture(GrTexture* texture);
1.70 +
1.71 + // Reset the internal bitmap
1.72 + void clear(uint8_t alpha) {
1.73 + fBM.eraseColor(SkColorSetARGB(alpha, alpha, alpha, alpha));
1.74 + }
1.75 +
1.76 + // Canonical usage utility that draws a single path and uploads it
1.77 + // to the GPU. The result is returned in "result".
1.78 + static GrTexture* DrawPathMaskToTexture(GrContext* context,
1.79 + const SkPath& path,
1.80 + const SkStrokeRec& stroke,
1.81 + const SkIRect& resultBounds,
1.82 + bool antiAlias,
1.83 + SkMatrix* matrix);
1.84 +
1.85 + // This utility routine is used to add a path's mask to some other draw.
1.86 + // The ClipMaskManager uses it to accumulate clip masks while the
1.87 + // GrSoftwarePathRenderer uses it to fulfill a drawPath call.
1.88 + // It draws with "texture" as a path mask into "target" using "rect" as
1.89 + // geometry and the current drawState. The current drawState is altered to
1.90 + // accommodate the mask.
1.91 + // Note that this method assumes that the GrPaint::kTotalStages slot in
1.92 + // the draw state can be used to hold the mask texture stage.
1.93 + // This method is really only intended to be used with the
1.94 + // output of DrawPathMaskToTexture.
1.95 + static void DrawToTargetWithPathMask(GrTexture* texture,
1.96 + GrDrawTarget* target,
1.97 + const SkIRect& rect);
1.98 +
1.99 +protected:
1.100 +private:
1.101 + GrContext* fContext;
1.102 + SkMatrix fMatrix;
1.103 + SkBitmap fBM;
1.104 + SkDraw fDraw;
1.105 + SkRasterClip fRasterClip;
1.106 +
1.107 + typedef SkNoncopyable INHERITED;
1.108 +};
1.109 +
1.110 +#endif // GrSWMaskHelper_DEFINED
