specialize bicubic filtering for scale-only

BUG=

Review URL: https://codereview.chromium.org/15941012

git-svn-id: http://skia.googlecode.com/svn/trunk@9360 2bbb7eff-a529-9590-31e7-b0007b416f81
This commit is contained in:
humper@google.com 2013-05-31 12:49:18 +00:00
parent 9e6793541f
commit 1922c2e62e

View File

@ -35,22 +35,49 @@ static float poly_eval(const float cc[4], float t) {
return cc[0] + t * (cc[1] + t * (cc[2] + t * cc[3]));
}
static void build_coeff4(SkFixed dst[4], const float src[16], float t) {
dst[0] = SkFloatToFixed(poly_eval(&src[ 0], t));
dst[1] = SkFloatToFixed(poly_eval(&src[ 4], t));
dst[2] = SkFloatToFixed(poly_eval(&src[ 8], t));
dst[3] = SkFloatToFixed(poly_eval(&src[12], t));
}
static void bicubicFilter(const SkBitmapProcState& s, int x, int y,
SkPMColor* SK_RESTRICT colors, int count) {
static void build_coeff4(SkFixed dst[4], float t) {
static const SkScalar coefficients[16] = {
DS( 1.0 / 18.0), DS(-9.0 / 18.0), DS( 15.0 / 18.0), DS( -7.0 / 18.0),
DS(16.0 / 18.0), DS( 0.0 / 18.0), DS(-36.0 / 18.0), DS( 21.0 / 18.0),
DS( 1.0 / 18.0), DS( 9.0 / 18.0), DS( 27.0 / 18.0), DS(-21.0 / 18.0),
DS( 0.0 / 18.0), DS( 0.0 / 18.0), DS( -6.0 / 18.0), DS( 7.0 / 18.0),
};
dst[0] = SkFloatToFixed(poly_eval(&coefficients[ 0], t));
dst[1] = SkFloatToFixed(poly_eval(&coefficients[ 4], t));
dst[2] = SkFloatToFixed(poly_eval(&coefficients[ 8], t));
dst[3] = SkFloatToFixed(poly_eval(&coefficients[12], t));
}
static SkPMColor doBicubicFilter(const SkBitmap *bm, SkFixed coeffX[4], SkFixed coeffY[4],
int x0, int x1, int x2, int x3,
int y0, int y1, int y2, int y3 )
{
SkPMColor s00 = *bm->getAddr32(x0, y0);
SkPMColor s10 = *bm->getAddr32(x1, y0);
SkPMColor s20 = *bm->getAddr32(x2, y0);
SkPMColor s30 = *bm->getAddr32(x3, y0);
SkPMColor s0 = cubicBlend(coeffX, s00, s10, s20, s30);
SkPMColor s01 = *bm->getAddr32(x0, y1);
SkPMColor s11 = *bm->getAddr32(x1, y1);
SkPMColor s21 = *bm->getAddr32(x2, y1);
SkPMColor s31 = *bm->getAddr32(x3, y1);
SkPMColor s1 = cubicBlend(coeffX, s01, s11, s21, s31);
SkPMColor s02 = *bm->getAddr32(x0, y2);
SkPMColor s12 = *bm->getAddr32(x1, y2);
SkPMColor s22 = *bm->getAddr32(x2, y2);
SkPMColor s32 = *bm->getAddr32(x3, y2);
SkPMColor s2 = cubicBlend(coeffX, s02, s12, s22, s32);
SkPMColor s03 = *bm->getAddr32(x0, y3);
SkPMColor s13 = *bm->getAddr32(x1, y3);
SkPMColor s23 = *bm->getAddr32(x2, y3);
SkPMColor s33 = *bm->getAddr32(x3, y3);
SkPMColor s3 = cubicBlend(coeffX, s03, s13, s23, s33);
return cubicBlend(coeffY, s0, s1, s2, s3);
}
static void bicubicFilter(const SkBitmapProcState& s, int x, int y,
SkPMColor* SK_RESTRICT colors, int count) {
const int maxX = s.fBitmap->width() - 1;
const int maxY = s.fBitmap->height() - 1;
@ -65,8 +92,8 @@ static void bicubicFilter(const SkBitmapProcState& s, int x, int y,
SkScalar fracty = srcPt.fY - SkScalarFloorToScalar(srcPt.fY);
SkFixed coeffX[4], coeffY[4];
build_coeff4(coeffX, coefficients, fractx);
build_coeff4(coeffY, coefficients, fracty);
build_coeff4(coeffX, fractx);
build_coeff4(coeffY, fracty);
int sx = SkScalarFloorToInt(srcPt.fX);
int sy = SkScalarFloorToInt(srcPt.fY);
@ -80,28 +107,47 @@ static void bicubicFilter(const SkBitmapProcState& s, int x, int y,
int y1 = SkClampMax(sy , maxY);
int y2 = SkClampMax(sy + 1, maxY);
int y3 = SkClampMax(sy + 2, maxY);
*colors++ = doBicubicFilter( s.fBitmap, coeffX, coeffY, x0, x1, x2, x3, y0, y1, y2, y3 );
x++;
}
}
static void bicubicFilter_ScaleOnly(const SkBitmapProcState &s, int x, int y,
SkPMColor *SK_RESTRICT colors, int count) {
const int maxX = s.fBitmap->width() - 1;
const int maxY = s.fBitmap->height() - 1;
SkPoint srcPt;
s.fInvProc(*s.fInvMatrix, SkIntToScalar(x), SkIntToScalar(y), &srcPt);
srcPt.fY -= SK_ScalarHalf;
SkScalar fracty = srcPt.fY - SkScalarFloorToScalar(srcPt.fY);
SkFixed coeffX[4], coeffY[4];
build_coeff4(coeffY, fracty);
int sy = SkScalarFloorToInt(srcPt.fY);
int y0 = SkClampMax(sy - 1, maxY);
int y1 = SkClampMax(sy , maxY);
int y2 = SkClampMax(sy + 1, maxY);
int y3 = SkClampMax(sy + 2, maxY);
while (count-- > 0) {
s.fInvProc(*s.fInvMatrix, SkIntToScalar(x), SkIntToScalar(y), &srcPt);
srcPt.fX -= SK_ScalarHalf;
SkScalar fractx = srcPt.fX - SkScalarFloorToScalar(srcPt.fX);
build_coeff4(coeffX, fractx);
int sx = SkScalarFloorToInt(srcPt.fX);
// Here is where we can support other tile modes (e.g. repeat or mirror)
int x0 = SkClampMax(sx - 1, maxX);
int x1 = SkClampMax(sx , maxX);
int x2 = SkClampMax(sx + 1, maxX);
int x3 = SkClampMax(sx + 2, maxX);
*colors++ = doBicubicFilter( s.fBitmap, coeffX, coeffY, x0, x1, x2, x3, y0, y1, y2, y3 );
SkPMColor s00 = *s.fBitmap->getAddr32(x0, y0);
SkPMColor s10 = *s.fBitmap->getAddr32(x1, y0);
SkPMColor s20 = *s.fBitmap->getAddr32(x2, y0);
SkPMColor s30 = *s.fBitmap->getAddr32(x3, y0);
SkPMColor s0 = cubicBlend(coeffX, s00, s10, s20, s30);
SkPMColor s01 = *s.fBitmap->getAddr32(x0, y1);
SkPMColor s11 = *s.fBitmap->getAddr32(x1, y1);
SkPMColor s21 = *s.fBitmap->getAddr32(x2, y1);
SkPMColor s31 = *s.fBitmap->getAddr32(x3, y1);
SkPMColor s1 = cubicBlend(coeffX, s01, s11, s21, s31);
SkPMColor s02 = *s.fBitmap->getAddr32(x0, y2);
SkPMColor s12 = *s.fBitmap->getAddr32(x1, y2);
SkPMColor s22 = *s.fBitmap->getAddr32(x2, y2);
SkPMColor s32 = *s.fBitmap->getAddr32(x3, y2);
SkPMColor s2 = cubicBlend(coeffX, s02, s12, s22, s32);
SkPMColor s03 = *s.fBitmap->getAddr32(x0, y3);
SkPMColor s13 = *s.fBitmap->getAddr32(x1, y3);
SkPMColor s23 = *s.fBitmap->getAddr32(x2, y3);
SkPMColor s33 = *s.fBitmap->getAddr32(x3, y3);
SkPMColor s3 = cubicBlend(coeffX, s03, s13, s23, s33);
*colors++ = cubicBlend(coeffY, s0, s1, s2, s3);
x++;
}
}
@ -130,6 +176,12 @@ SkBitmapProcState::chooseBicubicFilterProc(const SkPaint& paint) {
if (0xFF != paint.getAlpha()) {
return NULL;
}
return bicubicFilter;
if (fInvType & SkMatrix::kAffine_Mask) {
return bicubicFilter;
} else if (fInvType & SkMatrix::kScale_Mask) {
return bicubicFilter_ScaleOnly;
} else {
return NULL;
}
}