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-rw-r--r--skia/sgl/SkScan_Antihair.cpp214
1 files changed, 155 insertions, 59 deletions
diff --git a/skia/sgl/SkScan_Antihair.cpp b/skia/sgl/SkScan_Antihair.cpp
index ca36739..04e4690 100644
--- a/skia/sgl/SkScan_Antihair.cpp
+++ b/skia/sgl/SkScan_Antihair.cpp
@@ -1,6 +1,6 @@
/* libs/graphics/sgl/SkScan_Antihair.cpp
**
-** Copyright 2006, Google Inc.
+** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
@@ -23,6 +23,12 @@
#define HLINE_STACK_BUFFER 100
+static inline int SmallDot6Scale(int value, int dot6) {
+ SkASSERT((int16_t)value == value);
+ SkASSERT((unsigned)dot6 <= 64);
+ return SkMulS16(value, dot6) >> 6;
+}
+
//#define TEST_GAMMA
#ifdef TEST_GAMMA
@@ -52,8 +58,9 @@
#define ApplyGamma(table, alpha) SkToU8(alpha)
#endif
+///////////////////////////////////////////////////////////////////////////////
-static void call_hline_blitter(SkBlitter* blitter, int x, int y, int count, uint8_t alpha)
+static void call_hline_blitter(SkBlitter* blitter, int x, int y, int count, U8CPU alpha)
{
SkASSERT(count > 0);
@@ -74,7 +81,7 @@ static void call_hline_blitter(SkBlitter* blitter, int x, int y, int count, uint
} while (count > 0);
}
-static void hline(int x, int stopx, SkFixed fy, SkFixed /*slope*/, SkBlitter* blitter)
+static SkFixed hline(int x, int stopx, SkFixed fy, SkFixed /*slope*/, SkBlitter* blitter, int mod64)
{
SkASSERT(x < stopx);
int count = stopx - x;
@@ -84,16 +91,21 @@ static void hline(int x, int stopx, SkFixed fy, SkFixed /*slope*/, SkBlitter* bl
uint8_t a = (uint8_t)(fy >> 8);
// lower line
- if (a)
- call_hline_blitter(blitter, x, y, count, a);
+ unsigned ma = SmallDot6Scale(a, mod64);
+ if (ma) {
+ call_hline_blitter(blitter, x, y, count, ma);
+ }
// upper line
- a = (uint8_t)(255 - a);
- if (a)
- call_hline_blitter(blitter, x, y - 1, count, a);
+ ma = SmallDot6Scale(255 - a, mod64);
+ if (ma) {
+ call_hline_blitter(blitter, x, y - 1, count, ma);
+ }
+
+ return fy - SK_Fixed1/2;
}
-static void horish(int x, int stopx, SkFixed fy, SkFixed dy, SkBlitter* blitter)
+static SkFixed horish(int x, int stopx, SkFixed fy, SkFixed dy, SkBlitter* blitter, int mod64)
{
SkASSERT(x < stopx);
@@ -110,19 +122,19 @@ static void horish(int x, int stopx, SkFixed fy, SkFixed dy, SkBlitter* blitter)
do {
int lower_y = fy >> 16;
uint8_t a = (uint8_t)(fy >> 8);
-
- if (a)
+ unsigned ma = SmallDot6Scale(a, mod64);
+ if (ma)
{
- aa[0] = ApplyGamma(gamma, a);
+ aa[0] = ApplyGamma(gamma, ma);
blitter->blitAntiH(x, lower_y, aa, runs);
// the clipping blitters might edit runs, but should not affect us
SkASSERT(runs[0] == 1);
SkASSERT(runs[1] == 0);
}
- a = (uint8_t)(255 - a);
- if (a)
+ ma = SmallDot6Scale(255 - a, mod64);
+ if (ma)
{
- aa[0] = ApplyGamma(gamma, a);
+ aa[0] = ApplyGamma(gamma, ma);
blitter->blitAntiH(x, lower_y - 1, aa, runs);
// the clipping blitters might edit runs, but should not affect us
SkASSERT(runs[0] == 1);
@@ -130,9 +142,11 @@ static void horish(int x, int stopx, SkFixed fy, SkFixed dy, SkBlitter* blitter)
}
fy += dy;
} while (++x < stopx);
+
+ return fy - SK_Fixed1/2;
}
-static void vline(int y, int stopy, SkFixed fx, SkFixed /*slope*/, SkBlitter* blitter)
+static SkFixed vline(int y, int stopy, SkFixed fx, SkFixed /*slope*/, SkBlitter* blitter, int mod64)
{
SkASSERT(y < stopy);
fx += SK_Fixed1/2;
@@ -140,14 +154,17 @@ static void vline(int y, int stopy, SkFixed fx, SkFixed /*slope*/, SkBlitter* bl
int x = fx >> 16;
int a = (uint8_t)(fx >> 8);
- if (a)
- blitter->blitV(x, y, stopy - y, ApplyGamma(gGammaTable, a));
- a = 255 - a;
- if (a)
- blitter->blitV(x - 1, y, stopy - y, ApplyGamma(gGammaTable, a));
+ unsigned ma = SmallDot6Scale(a, mod64);
+ if (ma)
+ blitter->blitV(x, y, stopy - y, ApplyGamma(gGammaTable, ma));
+ ma = SmallDot6Scale(255 - a, mod64);
+ if (ma)
+ blitter->blitV(x - 1, y, stopy - y, ApplyGamma(gGammaTable, ma));
+
+ return fx - SK_Fixed1/2;
}
-static void vertish(int y, int stopy, SkFixed fx, SkFixed dx, SkBlitter* blitter)
+static SkFixed vertish(int y, int stopy, SkFixed fx, SkFixed dx, SkBlitter* blitter, int mod64)
{
SkASSERT(y < stopy);
#ifdef TEST_GAMMA
@@ -164,8 +181,8 @@ static void vertish(int y, int stopy, SkFixed fx, SkFixed dx, SkBlitter* blitter
int x = fx >> 16;
uint8_t a = (uint8_t)(fx >> 8);
- aa[0] = ApplyGamma(gamma, 255 - a);
- aa[1] = ApplyGamma(gamma, a);
+ aa[0] = ApplyGamma(gamma, SmallDot6Scale(255 - a, mod64));
+ aa[1] = ApplyGamma(gamma, SmallDot6Scale(a, mod64));
// the clippng blitters might overwrite this guy, so we have to reset it each time
runs[1] = 1;
blitter->blitAntiH(x - 1, y, aa, runs);
@@ -174,9 +191,11 @@ static void vertish(int y, int stopy, SkFixed fx, SkFixed dx, SkBlitter* blitter
SkASSERT(runs[2] == 0);
fx += dx;
} while (++y < stopy);
+
+ return fx - SK_Fixed1/2;
}
-typedef void (*LineProc)(int istart, int istop, SkFixed fstart, SkFixed slope, SkBlitter*);
+typedef SkFixed (*LineProc)(int istart, int istop, SkFixed fstart, SkFixed slope, SkBlitter*, int);
static inline SkFixed fastfixdiv(SkFDot6 a, SkFDot6 b)
{
@@ -184,11 +203,6 @@ static inline SkFixed fastfixdiv(SkFDot6 a, SkFDot6 b)
SkASSERT(b != 0);
return (a << 16) / b;
}
-static inline SkFDot6 fastfixmul(SkFixed fixed, SkFDot6 b)
-{
- SkASSERT(SkAbs32(fixed) <= SK_Fixed1 && SkAbs32(b) <= SkIntToFDot6(511));
- return (fixed * b + 0x8000) >> 16;
-}
static void do_anti_hairline(SkFDot6 x0, SkFDot6 y0, SkFDot6 x1, SkFDot6 y1,
const SkIRect* clip, SkBlitter* blitter)
@@ -205,35 +219,40 @@ static void do_anti_hairline(SkFDot6 x0, SkFDot6 y0, SkFDot6 x1, SkFDot6 y1,
return;
}
+ int scaleStart, scaleStop;
int istart, istop;
SkFixed fstart, slope;
LineProc proc;
if (SkAbs32(x1 - x0) > SkAbs32(y1 - y0)) // mostly horizontal
{
- if (x0 > x1) // we want to go left-to-right
- {
+ if (x0 > x1) { // we want to go left-to-right
SkTSwap<SkFDot6>(x0, x1);
SkTSwap<SkFDot6>(y0, y1);
}
- istart = SkFDot6Round(x0);
- istop = SkFDot6Round(x1);
- if (istart == istop) // too short to draw
- return;
- if (y0 == y1) // completely horizontal, take fast case
- {
+ istart = SkFDot6Floor(x0);
+ istop = SkFDot6Ceil(x1);
+ fstart = SkFDot6ToFixed(y0);
+ if (y0 == y1) { // completely horizontal, take fast case
slope = 0;
- fstart = SkFDot6ToFixed(y0);
proc = hline;
- }
- else
- {
+ } else {
slope = fastfixdiv(y1 - y0, x1 - x0);
SkASSERT(slope >= -SK_Fixed1 && slope <= SK_Fixed1);
- fstart = SkFDot6ToFixed(y0 + fastfixmul(slope, (32 - x0) & 63));
+ fstart += (slope * (32 - (x0 & 63)) + 32) >> 6;
proc = horish;
}
+
+ SkASSERT(istop > istart);
+ if (istop - istart == 1) {
+ scaleStart = x1 - x0;
+ SkASSERT(scaleStart >= 0 && scaleStart <= 64);
+ scaleStop = 0;
+ } else {
+ scaleStart = 64 - (x0 & 63);
+ scaleStop = x1 & 63;
+ }
if (clip)
{
@@ -243,12 +262,16 @@ static void do_anti_hairline(SkFDot6 x0, SkFDot6 y0, SkFDot6 x1, SkFDot6 y1,
{
fstart += slope * (clip->fLeft - istart);
istart = clip->fLeft;
+ scaleStart = 64;
}
- if (istop > clip->fRight)
+ if (istop > clip->fRight) {
istop = clip->fRight;
+ scaleStop = 64;
+ }
SkASSERT(istart <= istop);
if (istart == istop)
return;
+
// now test if our Y values are completely inside the clip
int top, bottom;
if (slope >= 0) // T2B
@@ -274,25 +297,36 @@ static void do_anti_hairline(SkFDot6 x0, SkFDot6 y0, SkFDot6 x1, SkFDot6 y1,
SkTSwap<SkFDot6>(x0, x1);
SkTSwap<SkFDot6>(y0, y1);
}
- istart = SkFDot6Round(y0);
- istop = SkFDot6Round(y1);
- if (istart == istop) // too short to draw
- return;
+ istart = SkFDot6Floor(y0);
+ istop = SkFDot6Ceil(y1);
+ fstart = SkFDot6ToFixed(x0);
if (x0 == x1)
{
+ if (y0 == y1) { // are we zero length?
+ return; // nothing to do
+ }
slope = 0;
- fstart = SkFDot6ToFixed(x0);
proc = vline;
}
else
{
slope = fastfixdiv(x1 - x0, y1 - y0);
SkASSERT(slope <= SK_Fixed1 && slope >= -SK_Fixed1);
- fstart = SkFDot6ToFixed(x0 + fastfixmul(slope, (32 - y0) & 63));
+ fstart += (slope * (32 - (y0 & 63)) + 32) >> 6;
proc = vertish;
}
+ SkASSERT(istop > istart);
+ if (istop - istart == 1) {
+ scaleStart = y1 - y0;
+ SkASSERT(scaleStart >= 0 && scaleStart <= 64);
+ scaleStop = 0;
+ } else {
+ scaleStart = 64 - (y0 & 63);
+ scaleStop = y1 & 63;
+ }
+
if (clip)
{
if (istart >= clip->fBottom || istop <= clip->fTop)
@@ -301,12 +335,16 @@ static void do_anti_hairline(SkFDot6 x0, SkFDot6 y0, SkFDot6 x1, SkFDot6 y1,
{
fstart += slope * (clip->fTop - istart);
istart = clip->fTop;
+ scaleStart = 64;
}
- if (istop > clip->fBottom)
+ if (istop > clip->fBottom) {
istop = clip->fBottom;
+ scaleStop = 64;
+ }
SkASSERT(istart <= istop);
if (istart == istop)
return;
+
// now test if our X values are completely inside the clip
int left, right;
if (slope >= 0) // L2R
@@ -332,7 +370,16 @@ static void do_anti_hairline(SkFDot6 x0, SkFDot6 y0, SkFDot6 x1, SkFDot6 y1,
rectClipper.init(blitter, *clip);
blitter = &rectClipper;
}
- proc(istart, istop, fstart, slope, blitter);
+
+ fstart = proc(istart, istart + 1, fstart, slope, blitter, scaleStart);
+ istart += 1;
+ int fullSpans = istop - istart - 1;
+ if (fullSpans > 0) {
+ fstart = proc(istart, istart + fullSpans, fstart, slope, blitter, 64);
+ }
+ if (scaleStop > 0) {
+ proc(istop - 1, istop, fstart, slope, blitter, scaleStop);
+ }
}
void SkScan::AntiHairLine(const SkPoint& pt0, const SkPoint& pt1,
@@ -360,10 +407,10 @@ void SkScan::AntiHairLine(const SkPoint& pt0, const SkPoint& pt1,
SkFDot6 bottom = SkMax32(y0, y1);
SkIRect ir;
- ir.set( SkFDot6Round(left) - 1,
- SkFDot6Round(top) - 1,
- SkFDot6Round(right) + 1,
- SkFDot6Round(bottom) + 1);
+ ir.set( SkFDot6Floor(left) - 1,
+ SkFDot6Floor(top) - 1,
+ SkFDot6Ceil(right) + 1,
+ SkFDot6Ceil(bottom) + 1);
if (clip->quickReject(ir))
return;
@@ -536,12 +583,61 @@ void SkScan::AntiFillXRect(const SkXRect& xr, const SkRegion* clip,
#ifdef SK_SCALAR_IS_FLOAT
-void SkScan::AntiFillRect(const SkRect& r, const SkRegion* clip,
- SkBlitter* blitter) {
+/* This guy takes a float-rect, but with the key improvement that it has
+ already been clipped, so we know that it is safe to convert it into a
+ XRect (fixedpoint), as it won't overflow.
+*/
+static void antifillrect(const SkRect& r, SkBlitter* blitter) {
SkXRect xr;
XRect_set(&xr, r);
- SkScan::AntiFillXRect(xr, clip, blitter);
+ antifillrect(xr, blitter);
+}
+
+/* We repeat the clipping logic of AntiFillXRect because the float rect might
+ overflow if we blindly converted it to an XRect. This sucks that we have to
+ repeat the clipping logic, but I don't see how to share the code/logic.
+
+ We clip r (as needed) into one or more (smaller) float rects, and then pass
+ those to our version of antifillrect, which converts it into an XRect and
+ then calls the blit.
+*/
+void SkScan::AntiFillRect(const SkRect& r, const SkRegion* clip,
+ SkBlitter* blitter) {
+ if (clip) {
+ SkIRect outerBounds;
+ r.roundOut(&outerBounds);
+
+ if (clip->isRect()) {
+ const SkIRect& clipBounds = clip->getBounds();
+
+ if (clipBounds.contains(outerBounds)) {
+ antifillrect(r, blitter);
+ } else {
+ SkRect tmpR;
+ // this keeps our original edges fractional
+ tmpR.set(clipBounds);
+ if (tmpR.intersect(r)) {
+ antifillrect(tmpR, blitter);
+ }
+ }
+ } else {
+ SkRegion::Cliperator clipper(*clip, outerBounds);
+ const SkIRect& rr = clipper.rect();
+
+ while (!clipper.done()) {
+ SkRect tmpR;
+ // this keeps our original edges fractional
+ tmpR.set(rr);
+ if (tmpR.intersect(r)) {
+ antifillrect(tmpR, blitter);
+ }
+ clipper.next();
+ }
+ }
+ } else {
+ antifillrect(r, blitter);
+ }
}
#endif
generated by cgit v1.1 at 2025-01-27 09:43:52 +0000