DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (d8847129d134)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148
/*
 * Copyright 2013 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "SkErrorInternals.h"
#include "SkConvolver.h"
#include "SkBitmapProcState.h"
#include "SkBitmap.h"
#include "SkColor.h"
#include "SkColorPriv.h"
#include "SkConvolver.h"
#include "SkUnPreMultiply.h"
#include "SkShader.h"
#include "SkRTConf.h"
#include "SkMath.h"

// These are the per-scanline callbacks that are used when we must resort to
// resampling an image as it is blitted.  Typically these are used only when
// the image is rotated or has some other complex transformation applied.
// Scaled images will usually be rescaled directly before rasterization.

namespace {

template <typename Color, typename ColorPacker>
void highQualityFilter(ColorPacker pack, const SkBitmapProcState& s, int x, int y, Color* SK_RESTRICT colors, int count) {
    const int maxX = s.fBitmap->width();
    const int maxY = s.fBitmap->height();

    while (count-- > 0) {
        SkPoint srcPt;
        s.fInvProc(s.fInvMatrix, x + 0.5f,
                    y + 0.5f, &srcPt);
        srcPt.fX -= SK_ScalarHalf;
        srcPt.fY -= SK_ScalarHalf;

        SkScalar weight = 0;
        SkScalar fr = 0, fg = 0, fb = 0, fa = 0;

        int y0 = SkClampMax(SkScalarCeilToInt(srcPt.fY-s.getBitmapFilter()->width()), maxY);
        int y1 = SkClampMax(SkScalarFloorToInt(srcPt.fY+s.getBitmapFilter()->width()+1), maxY);
        int x0 = SkClampMax(SkScalarCeilToInt(srcPt.fX-s.getBitmapFilter()->width()), maxX);
        int x1 = SkClampMax(SkScalarFloorToInt(srcPt.fX+s.getBitmapFilter()->width())+1, maxX);

        for (int srcY = y0; srcY < y1; srcY++) {
            SkScalar yWeight = s.getBitmapFilter()->lookupScalar((srcPt.fY - srcY));

            for (int srcX = x0; srcX < x1 ; srcX++) {
                SkScalar xWeight = s.getBitmapFilter()->lookupScalar((srcPt.fX - srcX));

                SkScalar combined_weight = SkScalarMul(xWeight, yWeight);

                SkPMColor c = *s.fBitmap->getAddr32(srcX, srcY);
                fr += combined_weight * SkGetPackedR32(c);
                fg += combined_weight * SkGetPackedG32(c);
                fb += combined_weight * SkGetPackedB32(c);
                fa += combined_weight * SkGetPackedA32(c);
                weight += combined_weight;
            }
        }

        fr = SkScalarDiv(fr, weight);
        fg = SkScalarDiv(fg, weight);
        fb = SkScalarDiv(fb, weight);
        fa = SkScalarDiv(fa, weight);

        int a = SkClampMax(SkScalarRoundToInt(fa), 255);
        int r = SkClampMax(SkScalarRoundToInt(fr), a);
        int g = SkClampMax(SkScalarRoundToInt(fg), a);
        int b = SkClampMax(SkScalarRoundToInt(fb), a);

        *colors++ = pack(a, r, g, b);

        x++;
    }
}

uint16_t PackTo565(int /*a*/, int r, int g, int b) {
    return SkPack888ToRGB16(r, g, b);
}

}  // namespace

void highQualityFilter32(const SkBitmapProcState& s, int x, int y, SkPMColor* SK_RESTRICT colors, int count) {
    highQualityFilter(&SkPackARGB32, s, x, y, colors, count);
}

void highQualityFilter16(const SkBitmapProcState& s, int x, int y, uint16_t* SK_RESTRICT colors, int count) {
    highQualityFilter(&PackTo565, s, x, y, colors, count);
}


SK_CONF_DECLARE(const char *, c_bitmapFilter, "bitmap.filter", "mitchell", "Which scanline bitmap filter to use [mitchell, lanczos, hamming, gaussian, triangle, box]");

SkBitmapFilter *SkBitmapFilter::Allocate() {
    if (!strcmp(c_bitmapFilter, "mitchell")) {
        return SkNEW_ARGS(SkMitchellFilter,(1.f/3.f,1.f/3.f));
    } else if (!strcmp(c_bitmapFilter, "lanczos")) {
        return SkNEW(SkLanczosFilter);
    } else if (!strcmp(c_bitmapFilter, "hamming")) {
        return SkNEW(SkHammingFilter);
    } else if (!strcmp(c_bitmapFilter, "gaussian")) {
        return SkNEW_ARGS(SkGaussianFilter,(2));
    } else if (!strcmp(c_bitmapFilter, "triangle")) {
        return SkNEW(SkTriangleFilter);
    } else if (!strcmp(c_bitmapFilter, "box")) {
        return SkNEW(SkBoxFilter);
    } else {
        SkDEBUGFAIL("Unknown filter type");
    }

    return NULL;
}

bool SkBitmapProcState::setBitmapFilterProcs() {
    if (fFilterLevel != SkPaint::kHigh_FilterLevel) {
        return false;
    }

    if (fAlphaScale != 256) {
        return false;
    }

    // TODO: consider supporting other colortypes (e.g. 565, A8)
    if (fBitmap->colorType() != kN32_SkColorType) {
        return false;
    }

    // TODO: consider supporting repeat and mirror
    if (SkShader::kClamp_TileMode != fTileModeX || SkShader::kClamp_TileMode != fTileModeY) {
        return false;
    }

    // TODO: is this right?  do we want fBitmapFilter allocated even if we can't set shader procs?
    if (fInvType & (SkMatrix::kAffine_Mask | SkMatrix::kScale_Mask)) {
        fBitmapFilter = SkBitmapFilter::Allocate();
    }

    if (fInvType & SkMatrix::kScale_Mask) {
        fShaderProc32 = highQualityFilter32;
        fShaderProc16 = highQualityFilter16;
        return true;
    } else {
        return false;
    }
}