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-rw-r--r--src/core/SkBitmapProcBicubic.cpp187
1 files changed, 187 insertions, 0 deletions
diff --git a/src/core/SkBitmapProcBicubic.cpp b/src/core/SkBitmapProcBicubic.cpp
new file mode 100644
index 0000000000..f2cd0e30e7
--- /dev/null
+++ b/src/core/SkBitmapProcBicubic.cpp
@@ -0,0 +1,187 @@
+/*
+ * 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 "SkBitmapProcState.h"
+#include "SkBitmap.h"
+#include "SkColor.h"
+#include "SkColorPriv.h"
+#include "SkUnPreMultiply.h"
+#include "SkRTConf.h"
+#include "SkShader.h"
+
+#define DS(x) SkDoubleToScalar(x)
+
+#define MUL(a, b) ((a) * (b))
+
+static inline SkPMColor cubicBlend(const SkFixed cc[4], SkPMColor c0, SkPMColor c1, SkPMColor c2, SkPMColor c3) {
+ SkFixed fa = MUL(cc[0], SkGetPackedA32(c0)) + MUL(cc[1], SkGetPackedA32(c1)) + MUL(cc[2], SkGetPackedA32(c2)) + MUL(cc[3], SkGetPackedA32(c3));
+ SkFixed fr = MUL(cc[0], SkGetPackedR32(c0)) + MUL(cc[1], SkGetPackedR32(c1)) + MUL(cc[2], SkGetPackedR32(c2)) + MUL(cc[3], SkGetPackedR32(c3));
+ SkFixed fg = MUL(cc[0], SkGetPackedG32(c0)) + MUL(cc[1], SkGetPackedG32(c1)) + MUL(cc[2], SkGetPackedG32(c2)) + MUL(cc[3], SkGetPackedG32(c3));
+ SkFixed fb = MUL(cc[0], SkGetPackedB32(c0)) + MUL(cc[1], SkGetPackedB32(c1)) + MUL(cc[2], SkGetPackedB32(c2)) + MUL(cc[3], SkGetPackedB32(c3));
+
+ int a = SkClampMax(SkFixedRoundToInt(fa), 255);
+ int r = SkClampMax(SkFixedRoundToInt(fr), a);
+ int g = SkClampMax(SkFixedRoundToInt(fg), a);
+ int b = SkClampMax(SkFixedRoundToInt(fb), a);
+
+ return SkPackARGB32(a, r, g, b);
+}
+
+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], 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;
+
+ while (count-- > 0) {
+ SkPoint srcPt;
+ s.fInvProc(*s.fInvMatrix, SkIntToScalar(x),
+ SkIntToScalar(y), &srcPt);
+ srcPt.fX -= SK_ScalarHalf;
+ srcPt.fY -= SK_ScalarHalf;
+ SkScalar fractx = srcPt.fX - SkScalarFloorToScalar(srcPt.fX);
+ SkScalar fracty = srcPt.fY - SkScalarFloorToScalar(srcPt.fY);
+
+ SkFixed coeffX[4], coeffY[4];
+ build_coeff4(coeffX, fractx);
+ build_coeff4(coeffY, fracty);
+
+ int sx = SkScalarFloorToInt(srcPt.fX);
+ int sy = SkScalarFloorToInt(srcPt.fY);
+
+ // 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);
+ int y0 = SkClampMax(sy - 1, maxY);
+ 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 );
+
+ x++;
+ }
+}
+
+SkBitmapProcState::ShaderProc32
+SkBitmapProcState::chooseBicubicFilterProc(const SkPaint& paint) {
+ // we need to be requested
+ uint32_t mask = SkPaint::kFilterBitmap_Flag
+ | SkPaint::kBicubicFilterBitmap_Flag
+ ;
+ if ((paint.getFlags() & mask) != mask) {
+ return NULL;
+ }
+
+ // TODO: consider supporting other configs (e.g. 565, A8)
+ if (fBitmap->config() != SkBitmap::kARGB_8888_Config) {
+ return NULL;
+ }
+
+ // TODO: consider supporting repeat and mirror
+ if (SkShader::kClamp_TileMode != fTileModeX || SkShader::kClamp_TileMode != fTileModeY) {
+ return NULL;
+ }
+
+ // TODO: support blending inside our procs
+ if (0xFF != paint.getAlpha()) {
+ return NULL;
+ }
+
+ if (fInvType & SkMatrix::kAffine_Mask) {
+ return bicubicFilter;
+ } else if (fInvType & SkMatrix::kScale_Mask) {
+ return bicubicFilter_ScaleOnly;
+ } else {
+ return NULL;
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-10 00:56:52 +0000