Remove the remainder of the skia source code from the Chromium repo....

skia/sgl/SkEdge.cpp

Index: skia/sgl/SkEdge.cpp
===================================================================
--- skia/sgl/SkEdge.cpp	(revision 16859)
+++ skia/sgl/SkEdge.cpp	(working copy)
@@ -1,506 +0,0 @@
-/* libs/graphics/sgl/SkEdge.cpp
-**
-** 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. 
-** You may obtain a copy of the License at 
-**
-**     http://www.apache.org/licenses/LICENSE-2.0 
-**
-** Unless required by applicable law or agreed to in writing, software 
-** distributed under the License is distributed on an "AS IS" BASIS, 
-** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
-** See the License for the specific language governing permissions and 
-** limitations under the License.
-*/
-
-#include "SkEdge.h"
-#include "SkFDot6.h"
-#include <limits>
-
-/*
-    In setLine, setQuadratic, setCubic, the first thing we do is to convert
-    the points into FDot6. This is modulated by the shift parameter, which
-    will either be 0, or something like 2 for antialiasing.
-
-    In the float case, we want to turn the float into .6 by saying pt * 64,
-    or pt * 256 for antialiasing. This is implemented as 1 << (shift + 6).
-
-    In the fixed case, we want to turn the fixed into .6 by saying pt >> 10,
-    or pt >> 8 for antialiasing. This is implemented as pt >> (10 - shift).
-*/
-
-/////////////////////////////////////////////////////////////////////////
-
-int SkEdge::setLine(const SkPoint& p0, const SkPoint& p1, const SkIRect* clip,
-                    int shift) {
-    SkFDot6 x0, y0, x1, y1;
-
-    {
-#ifdef SK_SCALAR_IS_FLOAT
-        float scale = float(1 << (shift + 6));
-        x0 = int(p0.fX * scale);
-        y0 = int(p0.fY * scale);
-        x1 = int(p1.fX * scale);
-        y1 = int(p1.fY * scale);
-#else
-        shift = 10 - shift;
-        x0 = p0.fX >> shift;
-        y0 = p0.fY >> shift;
-        x1 = p1.fX >> shift;
-        y1 = p1.fY >> shift;
-#endif
-    }
-
-    int winding = 1;
-
-    if (y0 > y1) {
-        SkTSwap(x0, x1);
-        SkTSwap(y0, y1);
-        winding = -1;
-    }
-
-    int top = SkFDot6Round(y0);
-    int bot = SkFDot6Round(y1);
-
-    // are we a zero-height line?
-    if (top == bot) {
-        return 0;
-    }
-    // are we completely above or below the clip?
-    if (NULL != clip && (top >= clip->fBottom || bot <= clip->fTop)) {
-        return 0;
-    }
-
-    SkFixed slope = SkFDot6Div(x1 - x0, y1 - y0);
-
-    fX          = SkFDot6ToFixed(x0 + SkFixedMul(slope, (32 - y0) & 63));   // + SK_Fixed1/2
-    fDX         = slope;
-#if 0
-    // CHANGED FOR CHROME
-    fFirstY     = top;
-    fLastY      = bot - 1;
-#else
-    fFirstY     = top;
-    if (top != (long)fFirstY) {
-        if (fFirstY < top) {
-            fFirstY = std::numeric_limits<int16_t>::max();
-        } else {
-            fFirstY = std::numeric_limits<int16_t>::min();
-        }
-        fX -= fDX * (top - (long)fFirstY);
-    }
-    fLastY      = bot - 1;
-    if (bot-1 != (long)fLastY) {
-        if (fLastY < bot-1) {
-            fLastY = std::numeric_limits<int16_t>::max();
-        } else {
-            fLastY = std::numeric_limits<int16_t>::min();
-        }
-    }
-#endif
-    fCurveCount = 0;
-    fWinding    = SkToS8(winding);
-    fCurveShift = 0;
-
-    if (clip) {
-        this->chopLineWithClip(*clip);
-    }
-    return 1;
-}
-
-// called from a curve subclass
-int SkEdge::updateLine(SkFixed x0, SkFixed y0, SkFixed x1, SkFixed y1)
-{
-    SkASSERT(fWinding == 1 || fWinding == -1);
-    SkASSERT(fCurveCount != 0);
-//    SkASSERT(fCurveShift != 0);
-
-    y0 >>= 10;
-    y1 >>= 10;
-
-    SkASSERT(y0 <= y1);
-
-    int top = SkFDot6Round(y0);
-    int bot = SkFDot6Round(y1);
-
-//  SkASSERT(top >= fFirstY);
-
-    // are we a zero-height line?
-    if (top == bot)
-        return 0;
-
-    x0 >>= 10;
-    x1 >>= 10;
-
-    SkFixed slope = SkFDot6Div(x1 - x0, y1 - y0);
-
-    fX          = SkFDot6ToFixed(x0 + SkFixedMul(slope, (32 - y0) & 63));   // + SK_Fixed1/2
-    fDX         = slope;
-    fFirstY     = top;
-    fLastY      = bot - 1;
-
-    return 1;
-}
-
-void SkEdge::chopLineWithClip(const SkIRect& clip)
-{
-    int top = fFirstY;
-
-    SkASSERT(top < clip.fBottom);
-
-    // clip the line to the top
-    if (top < clip.fTop)
-    {
-        SkASSERT(fLastY >= clip.fTop);
-        fX += fDX * (clip.fTop - top);
-        fFirstY = clip.fTop;
-    }
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-/*  We store 1<<shift in a (signed) byte, so its maximum value is 1<<6 == 64.
-    Note that this limits the number of lines we use to approximate a curve.
-    If we need to increase this, we need to store fCurveCount in something
-    larger than int8_t.
-*/
-#define MAX_COEFF_SHIFT     6
-
-static inline SkFDot6 cheap_distance(SkFDot6 dx, SkFDot6 dy)
-{
-    dx = SkAbs32(dx);
-    dy = SkAbs32(dy);
-    // return max + min/2
-    if (dx > dy)
-        dx += dy >> 1;
-    else
-        dx = dy + (dx >> 1);
-    return dx;
-}
-
-static inline int diff_to_shift(SkFDot6 dx, SkFDot6 dy)
-{
-    // cheap calc of distance from center of p0-p2 to the center of the curve
-    SkFDot6 dist = cheap_distance(dx, dy);
-
-    // shift down dist (it is currently in dot6)
-    // down by 5 should give us 1/2 pixel accuracy (assuming our dist is accurate...)
-    // this is chosen by heuristic: make it as big as possible (to minimize segments)
-    // ... but small enough so that our curves still look smooth
-    dist = (dist + (1 << 4)) >> 5;
-
-    // each subdivision (shift value) cuts this dist (error) by 1/4
-    return (32 - SkCLZ(dist)) >> 1;
-}
-
-int SkQuadraticEdge::setQuadratic(const SkPoint pts[3], const SkIRect* clip, int shift)
-{
-    SkFDot6 x0, y0, x1, y1, x2, y2;
-
-    {
-#ifdef SK_SCALAR_IS_FLOAT
-        float scale = float(1 << (shift + 6));
-        x0 = int(pts[0].fX * scale);
-        y0 = int(pts[0].fY * scale);
-        x1 = int(pts[1].fX * scale);
-        y1 = int(pts[1].fY * scale);
-        x2 = int(pts[2].fX * scale);
-        y2 = int(pts[2].fY * scale);
-#else
-        shift = 10 - shift;
-        x0 = pts[0].fX >> shift;
-        y0 = pts[0].fY >> shift;
-        x1 = pts[1].fX >> shift;
-        y1 = pts[1].fY >> shift;
-        x2 = pts[2].fX >> shift;
-        y2 = pts[2].fY >> shift;
-#endif
-    }
-
-    int winding = 1;
-    if (y0 > y2)
-    {
-        SkTSwap(x0, x2);
-        SkTSwap(y0, y2);
-        winding = -1;
-    }
-    SkASSERT(y0 <= y1 && y1 <= y2);
-
-    int top = SkFDot6Round(y0);
-    int bot = SkFDot6Round(y2);
-
-    // are we a zero-height quad (line)?
-    if (top == bot)
-        return 0;
-    // are we completely above or below the clip?
-    if (clip && (top >= clip->fBottom || bot <= clip->fTop))
-        return 0;
-
-    // compute number of steps needed (1 << shift)
-    {
-        SkFDot6 dx = ((x1 << 1) - x0 - x2) >> 2;
-        SkFDot6 dy = ((y1 << 1) - y0 - y2) >> 2;
-        shift = diff_to_shift(dx, dy);
-        SkASSERT(shift >= 0);
-    }
-    // need at least 1 subdivision for our bias trick
-    if (shift == 0) {
-        shift = 1;
-    } else if (shift > MAX_COEFF_SHIFT) {
-        shift = MAX_COEFF_SHIFT;
-    }
-    
-    fWinding    = SkToS8(winding);
-    fCurveShift = SkToU8(shift);
-    //fCubicDShift only set for cubics
-    fCurveCount = SkToS8(1 << shift);
-
-    SkFixed A = SkFDot6ToFixed(x0 - x1 - x1 + x2);
-    SkFixed B = SkFDot6ToFixed(x1 - x0 + x1 - x0);
-
-    fQx     = SkFDot6ToFixed(x0);
-    fQDx    = B + (A >> shift);     // biased by shift
-    fQDDx   = A >> (shift - 1);     // biased by shift
-
-    A = SkFDot6ToFixed(y0 - y1 - y1 + y2);
-    B = SkFDot6ToFixed(y1 - y0 + y1 - y0);
-
-    fQy     = SkFDot6ToFixed(y0);
-    fQDy    = B + (A >> shift);     // biased by shift
-    fQDDy   = A >> (shift - 1);     // biased by shift
-
-    fQLastX = SkFDot6ToFixed(x2);
-    fQLastY = SkFDot6ToFixed(y2);
-
-    if (clip)
-    {
-        do {
-            for (;!this->updateQuadratic();)
-                ;
-        } while (!this->intersectsClip(*clip));
-        this->chopLineWithClip(*clip);
-        return 1;
-    }
-    return this->updateQuadratic();
-}
-
-int SkQuadraticEdge::updateQuadratic()
-{
-    int     success;
-    int     count = fCurveCount;
-    SkFixed oldx = fQx;
-    SkFixed oldy = fQy;
-    SkFixed dx = fQDx;
-    SkFixed dy = fQDy;
-    SkFixed newx, newy;
-    int     shift = fCurveShift;
-
-    SkASSERT(count > 0);
-
-    do {
-        if (--count > 0)
-        {
-            newx    = oldx + (dx >> shift);
-            dx    += fQDDx;
-            newy    = oldy + (dy >> shift);
-            dy    += fQDDy;
-        }
-        else    // last segment
-        {
-            newx    = fQLastX;
-            newy    = fQLastY;
-        }
-        success = this->updateLine(oldx, oldy, newx, newy);
-        oldx = newx;
-        oldy = newy;
-    } while (count > 0 && !success);
-
-    fQx         = newx;
-    fQy         = newy;
-    fQDx        = dx;
-    fQDy        = dy;
-    fCurveCount = SkToS16(count);
-    return success;
-}
-
-/////////////////////////////////////////////////////////////////////////
-
-static inline int SkFDot6UpShift(SkFDot6 x, int upShift) {
-    SkASSERT((x << upShift >> upShift) == x);
-    return x << upShift;
-}
-
-/*  f(1/3) = (8a + 12b + 6c + d) / 27
-    f(2/3) = (a + 6b + 12c + 8d) / 27
-
-    f(1/3)-b = (8a - 15b + 6c + d) / 27
-    f(2/3)-c = (a + 6b - 15c + 8d) / 27
-
-    use 16/512 to approximate 1/27
-*/
-static SkFDot6 cubic_delta_from_line(SkFDot6 a, SkFDot6 b, SkFDot6 c, SkFDot6 d)
-{
-    SkFDot6 oneThird = ((a << 3) - ((b << 4) - b) + 6*c + d) * 19 >> 9;
-    SkFDot6 twoThird = (a + 6*b - ((c << 4) - c) + (d << 3)) * 19 >> 9;
-
-    return SkMax32(SkAbs32(oneThird), SkAbs32(twoThird));
-}
-
-int SkCubicEdge::setCubic(const SkPoint pts[4], const SkIRect* clip, int shift)
-{
-    SkFDot6 x0, y0, x1, y1, x2, y2, x3, y3;
-
-    {
-#ifdef SK_SCALAR_IS_FLOAT
-        float scale = float(1 << (shift + 6));
-        x0 = int(pts[0].fX * scale);
-        y0 = int(pts[0].fY * scale);
-        x1 = int(pts[1].fX * scale);
-        y1 = int(pts[1].fY * scale);
-        x2 = int(pts[2].fX * scale);
-        y2 = int(pts[2].fY * scale);
-        x3 = int(pts[3].fX * scale);
-        y3 = int(pts[3].fY * scale);
-#else
-        shift = 10 - shift;
-        x0 = pts[0].fX >> shift;
-        y0 = pts[0].fY >> shift;
-        x1 = pts[1].fX >> shift;
-        y1 = pts[1].fY >> shift;
-        x2 = pts[2].fX >> shift;
-        y2 = pts[2].fY >> shift;
-        x3 = pts[3].fX >> shift;
-        y3 = pts[3].fY >> shift;
-#endif
-    }
-
-    int winding = 1;
-    if (y0 > y3)
-    {
-        SkTSwap(x0, x3);
-        SkTSwap(x1, x2);
-        SkTSwap(y0, y3);
-        SkTSwap(y1, y2);
-        winding = -1;
-    }
-
-    int top = SkFDot6Round(y0);
-    int bot = SkFDot6Round(y3);
-
-    // are we a zero-height cubic (line)?
-    if (top == bot)
-        return 0;
-
-    // are we completely above or below the clip?
-    if (clip && (top >= clip->fBottom || bot <= clip->fTop))
-        return 0;
-
-    // compute number of steps needed (1 << shift)
-    {
-        // Can't use (center of curve - center of baseline), since center-of-curve
-        // need not be the max delta from the baseline (it could even be coincident)
-        // so we try just looking at the two off-curve points
-        SkFDot6 dx = cubic_delta_from_line(x0, x1, x2, x3);
-        SkFDot6 dy = cubic_delta_from_line(y0, y1, y2, y3);
-        // add 1 (by observation)
-        shift = diff_to_shift(dx, dy) + 1;
-    }
-    // need at least 1 subdivision for our bias trick
-    SkASSERT(shift > 0);
-    if (shift > MAX_COEFF_SHIFT) {
-        shift = MAX_COEFF_SHIFT;
-    }
-
-    /*  Since our in coming data is initially shifted down by 10 (or 8 in
-        antialias). That means the most we can shift up is 8. However, we
-        compute coefficients with a 3*, so the safest upshift is really 6
-    */
-    int upShift = 6;    // largest safe value
-    int downShift = shift + upShift - 10;
-    if (downShift < 0) {
-        downShift = 0;
-        upShift = 10 - shift;
-    }
-
-    fWinding    = SkToS8(winding);
-    fCurveCount = SkToS8(-1 << shift);
-    fCurveShift = SkToU8(shift);
-    fCubicDShift = SkToU8(downShift);
-
-    SkFixed B = SkFDot6UpShift(3 * (x1 - x0), upShift);
-    SkFixed C = SkFDot6UpShift(3 * (x0 - x1 - x1 + x2), upShift);
-    SkFixed D = SkFDot6UpShift(x3 + 3 * (x1 - x2) - x0, upShift);
-
-    fCx     = SkFDot6ToFixed(x0);
-    fCDx    = B + (C >> shift) + (D >> 2*shift);    // biased by shift
-    fCDDx   = 2*C + (3*D >> (shift - 1));           // biased by 2*shift
-    fCDDDx  = 3*D >> (shift - 1);                   // biased by 2*shift
-
-    B = SkFDot6UpShift(3 * (y1 - y0), upShift);
-    C = SkFDot6UpShift(3 * (y0 - y1 - y1 + y2), upShift);
-    D = SkFDot6UpShift(y3 + 3 * (y1 - y2) - y0, upShift);
-
-    fCy     = SkFDot6ToFixed(y0);
-    fCDy    = B + (C >> shift) + (D >> 2*shift);    // biased by shift
-    fCDDy   = 2*C + (3*D >> (shift - 1));           // biased by 2*shift
-    fCDDDy  = 3*D >> (shift - 1);                   // biased by 2*shift
-
-    fCLastX = SkFDot6ToFixed(x3);
-    fCLastY = SkFDot6ToFixed(y3);
-
-    if (clip)
-    {
-        do {
-            for (;!this->updateCubic();)
-                ;
-        } while (!this->intersectsClip(*clip));
-        this->chopLineWithClip(*clip);
-        return 1;
-    }
-    return this->updateCubic();
-}
-
-int SkCubicEdge::updateCubic()
-{
-    int     success;
-    int     count = fCurveCount;
-    SkFixed oldx = fCx;
-    SkFixed oldy = fCy;
-    SkFixed newx, newy;
-    const int ddshift = fCurveShift;
-    const int dshift = fCubicDShift;
-
-    SkASSERT(count < 0);
-
-    do {
-        if (++count < 0)
-        {
-            newx    = oldx + (fCDx >> dshift);
-            fCDx    += fCDDx >> ddshift;
-            fCDDx   += fCDDDx;
-
-            newy    = oldy + (fCDy >> dshift);
-            fCDy    += fCDDy >> ddshift;
-            fCDDy   += fCDDDy;
-        }
-        else    // last segment
-        {
-        //  SkDebugf("LastX err=%d, LastY err=%d\n", (oldx + (fCDx >> shift) - fLastX), (oldy + (fCDy >> shift) - fLastY));
-            newx    = fCLastX;
-            newy    = fCLastY;
-        }
-        success = this->updateLine(oldx, oldy, newx, newy);
-        oldx = newx;
-        oldy = newy;
-    } while (count < 0 && !success);
-
-    fCx         = newx;
-    fCy         = newy;
-    fCurveCount = SkToS16(count);
-    return success;
-}
-
-
-