зеркало из https://github.com/mozilla/moz-skia.git
Add new module for distance field generation.
This improves the speed over the previous method by 10x+, and makes using distance fields practical. BUG=skia:2173 R=bsalomon@google.com, robertphillips@google.com Author: jvanverth@google.com Review URL: https://codereview.chromium.org/178543007 git-svn-id: http://skia.googlecode.com/svn/trunk@13729 2bbb7eff-a529-9590-31e7-b0007b416f81
This commit is contained in:
commit-bot@chromium.org
Родитель
bfce48e0bc
Коммит
bf99824083
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@ -46,6 +46,7 @@
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#ifdef SK_DEBUG
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static const bool kDebugOnly = true;
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#define GR_DUMP_FONT_CACHE 0
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#else
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static const bool kDebugOnly = false;
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#endif
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@ -2408,6 +2409,18 @@ int tool_main(int argc, char** argv) {
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}
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#endif
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#if GR_DUMP_FONT_CACHE
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for (int i = 0; i < configs.count(); i++) {
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ConfigData config = gRec[configs[i]];
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if (kGPU_Backend == config.fBackend) {
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GrContext* gr = grFactory->get(config.fGLContextType);
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gr->dumpFontCache();
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}
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}
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#endif
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delete grFactory;
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#endif
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SkGraphics::Term();
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@ -70,6 +70,8 @@
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'<(skia_src_path)/core/SkDeviceProfile.cpp',
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'<(skia_src_path)/lazy/SkDiscardableMemoryPool.cpp',
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'<(skia_src_path)/lazy/SkDiscardablePixelRef.cpp',
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'<(skia_src_path)/core/SkDistanceFieldGen.cpp',
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'<(skia_src_path)/core/SkDistanceFieldGen.h',
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'<(skia_src_path)/core/SkDither.cpp',
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'<(skia_src_path)/core/SkDraw.cpp',
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'<(skia_src_path)/core/SkDrawLooper.cpp',
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@ -1,31 +0,0 @@
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#
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# Copyright 2013 Google Inc.
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#
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# Use of this source code is governed by a BSD-style license that can be
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# found in the LICENSE file.
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#
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{
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'targets': [
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{
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'target_name': 'edtaa',
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'type': 'none',
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'conditions': [
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[ 'skia_distancefield_fonts', {
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'type': 'static_library',
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'sources': [
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'../third_party/edtaa/edtaa3func.cpp',
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],
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'include_dirs': [
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'../third_party/edtaa/',
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],
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'all_dependent_settings': {
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'include_dirs': [
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'../third_party/edtaa/',
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],
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},
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}],
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],
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},
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],
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}
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@ -83,7 +83,6 @@
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'standalone_static_library': 1,
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'dependencies': [
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'core.gyp:*',
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'edtaa.gyp:*',
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'utils.gyp:*',
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],
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'includes': [
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@ -0,0 +1,401 @@
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/*
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* Copyright 2014 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "SkDistanceFieldGen.h"
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#include "SkPoint.h"
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struct DFData {
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float fAlpha; // alpha value of source texel
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float fDistSq; // distance squared to nearest (so far) edge texel
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SkPoint fDistVector; // distance vector to nearest (so far) edge texel
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};
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// We treat an "edge" as a place where we cross from a texel >= 128 to a texel < 128,
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// or vice versa. This means we just need to check if the MSBs are different.
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static bool found_edge(const unsigned char* imagePtr, int width) {
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const int offsets[8] = {-1, 1, -width-1, -width, -width+1, width-1, width, width+1 };
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// search for an edge
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int checkVal = *imagePtr >> 7;
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for (int i = 0; i < 8; ++i) {
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const unsigned char* checkPtr = imagePtr + offsets[i];
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if (checkVal ^ (*checkPtr >> 7)) {
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return true;
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}
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}
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return false;
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}
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static void init_glyph_data(DFData* data, char* edges, const unsigned char* image,
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int dataWidth, int dataHeight,
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int imageWidth, int imageHeight,
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int pad) {
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data += pad*dataWidth;
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data += pad;
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edges += (pad*dataWidth + pad);
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for (int j = 0; j < imageHeight; ++j) {
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for (int i = 0; i < imageWidth; ++i) {
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if (255 == *image) {
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data->fAlpha = 1.0f;
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} else {
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data->fAlpha = (*image)*0.00392156862f; // 1/255
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}
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if (i > 0 && i < imageWidth-1 && j > 0 && j < imageHeight-1 &&
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found_edge(image, imageWidth)) {
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*edges = 255; // using 255 makes for convenient debug rendering
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}
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++data;
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++image;
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++edges;
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}
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data += 2*pad;
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edges += 2*pad;
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}
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}
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// from Gustavson (2011)
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// computes the distance to an edge given an edge normal vector and a pixel's alpha value
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// assumes that direction has been pre-normalized
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static float edge_distance(const SkPoint& direction, float alpha) {
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float dx = direction.fX;
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float dy = direction.fY;
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float distance;
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if (SkScalarNearlyZero(dx) || SkScalarNearlyZero(dy)) {
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distance = 0.5f - alpha;
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} else {
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// this is easier if we treat the direction as being in the first octant
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// (other octants are symmetrical)
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dx = SkScalarAbs(dx);
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dy = SkScalarAbs(dy);
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if (dx < dy) {
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SkTSwap(dx, dy);
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}
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// a1 = 0.5*dy/dx is the smaller fractional area chopped off by the edge
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// to avoid the divide, we just consider the numerator
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float a1num = 0.5f*dy;
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// we now compute the approximate distance, depending where the alpha falls
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// relative to the edge fractional area
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// if 0 <= alpha < a1
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if (alpha*dx < a1num) {
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// TODO: find a way to do this without square roots?
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distance = 0.5f*(dx + dy) - SkScalarSqrt(2.0f*dx*dy*alpha);
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// if a1 <= alpha <= 1 - a1
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} else if (alpha*dx < (dx - a1num)) {
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distance = (0.5f - alpha)*dx;
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// if 1 - a1 < alpha <= 1
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} else {
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// TODO: find a way to do this without square roots?
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distance = -0.5f*(dx + dy) + SkScalarSqrt(2.0f*dx*dy*(1.0f - alpha));
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}
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}
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return distance;
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}
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static void init_distances(DFData* data, char* edges, int width, int height) {
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// skip one pixel border
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DFData* currData = data;
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DFData* prevData = data - width;
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DFData* nextData = data + width;
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for (int j = 0; j < height; ++j) {
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for (int i = 0; i < width; ++i) {
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if (*edges) {
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// we should not be in the one-pixel outside band
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SkASSERT(i > 0 && i < width-1 && j > 0 && j < height-1);
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// gradient will point from low to high
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// +y is down in this case
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// i.e., if you're outside, gradient points towards edge
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// if you're inside, gradient points away from edge
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SkPoint currGrad;
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currGrad.fX = (prevData+1)->fAlpha - (prevData-1)->fAlpha
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+ SK_ScalarSqrt2*(currData+1)->fAlpha
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- SK_ScalarSqrt2*(currData-1)->fAlpha
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+ (nextData+1)->fAlpha - (nextData-1)->fAlpha;
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currGrad.fY = (nextData-1)->fAlpha - (prevData-1)->fAlpha
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+ SK_ScalarSqrt2*nextData->fAlpha
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- SK_ScalarSqrt2*prevData->fAlpha
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+ (nextData+1)->fAlpha - (prevData+1)->fAlpha;
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currGrad.setLengthFast(1.0f);
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// init squared distance to edge and distance vector
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float dist = edge_distance(currGrad, currData->fAlpha);
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currGrad.scale(dist, &currData->fDistVector);
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currData->fDistSq = dist*dist;
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} else {
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// init distance to "far away"
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currData->fDistSq = 2000000.f;
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currData->fDistVector.fX = 1000.f;
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currData->fDistVector.fY = 1000.f;
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}
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++currData;
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++prevData;
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++nextData;
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++edges;
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}
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}
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}
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// Danielsson's 8SSEDT
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// first stage forward pass
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// (forward in Y, forward in X)
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static void F1(DFData* curr, int width) {
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// upper left
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DFData* check = curr - width-1;
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SkPoint distVec = check->fDistVector;
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float distSq = check->fDistSq - 2.0f*(distVec.fX + distVec.fY - 1.0f);
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if (distSq < curr->fDistSq) {
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distVec.fX -= 1.0f;
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distVec.fY -= 1.0f;
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curr->fDistSq = distSq;
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curr->fDistVector = distVec;
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}
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// up
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check = curr - width;
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distVec = check->fDistVector;
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distSq = check->fDistSq - 2.0f*distVec.fY + 1.0f;
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if (distSq < curr->fDistSq) {
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distVec.fY -= 1.0f;
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curr->fDistSq = distSq;
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curr->fDistVector = distVec;
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}
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// upper right
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check = curr - width+1;
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distVec = check->fDistVector;
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distSq = check->fDistSq + 2.0f*(distVec.fX - distVec.fY + 1.0f);
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if (distSq < curr->fDistSq) {
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distVec.fX += 1.0f;
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distVec.fY -= 1.0f;
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curr->fDistSq = distSq;
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curr->fDistVector = distVec;
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}
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// left
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check = curr - 1;
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distVec = check->fDistVector;
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distSq = check->fDistSq - 2.0f*distVec.fX + 1.0f;
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if (distSq < curr->fDistSq) {
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distVec.fX -= 1.0f;
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curr->fDistSq = distSq;
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curr->fDistVector = distVec;
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}
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}
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// second stage forward pass
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// (forward in Y, backward in X)
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static void F2(DFData* curr, int width) {
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// right
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DFData* check = curr + 1;
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float distSq = check->fDistSq;
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SkPoint distVec = check->fDistVector;
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distSq = check->fDistSq + 2.0f*distVec.fX + 1.0f;
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if (distSq < curr->fDistSq) {
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distVec.fX += 1.0f;
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curr->fDistSq = distSq;
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curr->fDistVector = distVec;
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}
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}
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// first stage backward pass
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// (backward in Y, forward in X)
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static void B1(DFData* curr, int width) {
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// left
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DFData* check = curr - 1;
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SkPoint distVec = check->fDistVector;
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float distSq = check->fDistSq - 2.0f*distVec.fX + 1.0f;
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if (distSq < curr->fDistSq) {
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distVec.fX -= 1.0f;
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curr->fDistSq = distSq;
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curr->fDistVector = distVec;
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}
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}
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// second stage backward pass
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// (backward in Y, backwards in X)
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static void B2(DFData* curr, int width) {
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// right
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DFData* check = curr + 1;
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SkPoint distVec = check->fDistVector;
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float distSq = check->fDistSq + 2.0f*distVec.fX + 1.0f;
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if (distSq < curr->fDistSq) {
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distVec.fX += 1.0f;
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curr->fDistSq = distSq;
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curr->fDistVector = distVec;
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}
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// bottom left
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check = curr + width-1;
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distVec = check->fDistVector;
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distSq = check->fDistSq - 2.0f*(distVec.fX - distVec.fY - 1.0f);
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if (distSq < curr->fDistSq) {
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distVec.fX -= 1.0f;
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distVec.fY += 1.0f;
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curr->fDistSq = distSq;
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curr->fDistVector = distVec;
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}
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// bottom
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check = curr + width;
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distVec = check->fDistVector;
|
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distSq = check->fDistSq + 2.0f*distVec.fY + 1.0f;
|
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if (distSq < curr->fDistSq) {
|
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distVec.fY += 1.0f;
|
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curr->fDistSq = distSq;
|
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curr->fDistVector = distVec;
|
||||
}
|
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|
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// bottom right
|
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check = curr + width+1;
|
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distVec = check->fDistVector;
|
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distSq = check->fDistSq + 2.0f*(distVec.fX + distVec.fY + 1.0f);
|
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if (distSq < curr->fDistSq) {
|
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distVec.fX += 1.0f;
|
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distVec.fY += 1.0f;
|
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curr->fDistSq = distSq;
|
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curr->fDistVector = distVec;
|
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}
|
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}
|
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|
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static unsigned char pack_distance_field_val(float dist, float distanceMagnitude) {
|
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if (dist <= -distanceMagnitude) {
|
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return 255;
|
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} else if (dist > distanceMagnitude) {
|
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return 0;
|
||||
} else {
|
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return (unsigned char)((distanceMagnitude-dist)*128.0f/distanceMagnitude);
|
||||
}
|
||||
}
|
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|
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// assumes an 8-bit image and distance field
|
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bool SkGenerateDistanceFieldFromImage(unsigned char* distanceField,
|
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const unsigned char* image,
|
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int width, int height,
|
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int distanceMagnitude) {
|
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SkASSERT(NULL != distanceField);
|
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SkASSERT(NULL != image);
|
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|
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// the final distance field will have additional texels on each side to handle
|
||||
// the maximum distance
|
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// we expand our temp data by one more on each side to simplify
|
||||
// the scanning code -- will always be treated as infinitely far away
|
||||
int pad = distanceMagnitude+1;
|
||||
|
||||
// set params for distance field data
|
||||
int dataWidth = width + 2*pad;
|
||||
int dataHeight = height + 2*pad;
|
||||
|
||||
// create temp data
|
||||
size_t dataSize = dataWidth*dataHeight*sizeof(DFData);
|
||||
SkAutoSMalloc<1024> dfStorage(dataSize);
|
||||
DFData* dataPtr = (DFData*) dfStorage.get();
|
||||
sk_bzero(dataPtr, dataSize);
|
||||
|
||||
SkAutoSMalloc<1024> edgeStorage(dataWidth*dataHeight*sizeof(char));
|
||||
char* edgePtr = (char*) edgeStorage.get();
|
||||
sk_bzero(edgePtr, dataWidth*dataHeight*sizeof(char));
|
||||
|
||||
// copy glyph into distance field storage
|
||||
init_glyph_data(dataPtr, edgePtr, image,
|
||||
dataWidth, dataHeight,
|
||||
width, height, pad);
|
||||
|
||||
// create initial distance data, particularly at edges
|
||||
init_distances(dataPtr, edgePtr, dataWidth, dataHeight);
|
||||
|
||||
// now perform Euclidean distance transform to propagate distances
|
||||
|
||||
// forwards in y
|
||||
DFData* currData = dataPtr+dataWidth+1; // skip outer buffer
|
||||
char* currEdge = edgePtr+dataWidth+1;
|
||||
for (int j = 1; j < dataHeight-1; ++j) {
|
||||
// forwards in x
|
||||
for (int i = 1; i < dataWidth-1; ++i) {
|
||||
// don't need to calculate distance for edge pixels
|
||||
if (!*currEdge) {
|
||||
F1(currData, dataWidth);
|
||||
}
|
||||
++currData;
|
||||
++currEdge;
|
||||
}
|
||||
|
||||
// backwards in x
|
||||
--currData; // reset to end
|
||||
--currEdge;
|
||||
for (int i = 1; i < dataWidth-1; ++i) {
|
||||
// don't need to calculate distance for edge pixels
|
||||
if (!*currEdge) {
|
||||
F2(currData, dataWidth);
|
||||
}
|
||||
--currData;
|
||||
--currEdge;
|
||||
}
|
||||
|
||||
currData += dataWidth+1;
|
||||
currEdge += dataWidth+1;
|
||||
}
|
||||
|
||||
// backwards in y
|
||||
currData = dataPtr+dataWidth*(dataHeight-2) - 1; // skip outer buffer
|
||||
currEdge = edgePtr+dataWidth*(dataHeight-2) - 1;
|
||||
for (int j = 1; j < dataHeight-1; ++j) {
|
||||
// forwards in x
|
||||
for (int i = 1; i < dataWidth-1; ++i) {
|
||||
// don't need to calculate distance for edge pixels
|
||||
if (!*currEdge) {
|
||||
B1(currData, dataWidth);
|
||||
}
|
||||
++currData;
|
||||
++currEdge;
|
||||
}
|
||||
|
||||
// backwards in x
|
||||
--currData; // reset to end
|
||||
--currEdge;
|
||||
for (int i = 1; i < dataWidth-1; ++i) {
|
||||
// don't need to calculate distance for edge pixels
|
||||
if (!*currEdge) {
|
||||
B2(currData, dataWidth);
|
||||
}
|
||||
--currData;
|
||||
--currEdge;
|
||||
}
|
||||
|
||||
currData -= dataWidth-1;
|
||||
currEdge -= dataWidth-1;
|
||||
}
|
||||
|
||||
// copy results to final distance field data
|
||||
currData = dataPtr + dataWidth+1;
|
||||
currEdge = edgePtr + dataWidth+1;
|
||||
unsigned char *dfPtr = distanceField;
|
||||
for (int j = 1; j < dataHeight-1; ++j) {
|
||||
for (int i = 1; i < dataWidth-1; ++i) {
|
||||
float dist;
|
||||
if (currData->fAlpha > 0.5f) {
|
||||
dist = -SkScalarSqrt(currData->fDistSq);
|
||||
} else {
|
||||
dist = SkScalarSqrt(currData->fDistSq);
|
||||
}
|
||||
|
||||
*dfPtr++ = pack_distance_field_val(dist, (float)distanceMagnitude);
|
||||
++currData;
|
||||
++currEdge;
|
||||
}
|
||||
currData += 2;
|
||||
currEdge += 2;
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
|
@ -0,0 +1,25 @@
|
|||
/*
|
||||
* Copyright 2014 Google Inc.
|
||||
*
|
||||
* Use of this source code is governed by a BSD-style license that can be
|
||||
* found in the LICENSE file.
|
||||
*/
|
||||
#ifndef SkDistanceFieldGen_DEFINED
|
||||
#define SkDistanceFieldGen_DEFINED
|
||||
|
||||
/** Given 8-bit mask data, generate the associated distance field
|
||||
|
||||
* @param distanceField The distance field to be generated. Should already be allocated
|
||||
* by the client with the padding below.
|
||||
* @param image 8-bit mask we're using to generate the distance field.
|
||||
* @param w Width of the image.
|
||||
* @param h Height of the image.
|
||||
* @param distanceMagnitude Largest possible absolute value for the distance. The distance field
|
||||
* will be padded to w + 2*distanceMagnitude, h + 2*distanceMagnitude.
|
||||
*/
|
||||
bool SkGenerateDistanceFieldFromImage(unsigned char* distanceField,
|
||||
const unsigned char* image,
|
||||
int w, int h,
|
||||
int distanceMagnitude);
|
||||
|
||||
#endif
|
||||
|
|
@ -13,7 +13,7 @@
|
|||
#include "SkString.h"
|
||||
|
||||
#if SK_DISTANCEFIELD_FONTS
|
||||
#include "edtaa3.h"
|
||||
#include "SkDistanceFieldGen.h"
|
||||
#endif
|
||||
|
||||
///////////////////////////////////////////////////////////////////////////////
|
||||
|
|
@ -199,8 +199,9 @@ void GrFontCache::dump() const {
|
|||
#endif
|
||||
|
||||
#if SK_DISTANCEFIELD_FONTS
|
||||
#define DISTANCE_FIELD_PAD 4
|
||||
#define DISTANCE_FIELD_RANGE (4.0)
|
||||
// this acts as the max magnitude for the distance field,
|
||||
// as well as the pad we need around the glyph
|
||||
#define DISTANCE_FIELD_RANGE 4
|
||||
#endif
|
||||
|
||||
/*
|
||||
|
|
@ -253,10 +254,10 @@ GrGlyph* GrTextStrike::generateGlyph(GrGlyph::PackedID packed,
|
|||
#if SK_DISTANCEFIELD_FONTS
|
||||
// expand bounds to hold full distance field data
|
||||
if (fUseDistanceField) {
|
||||
bounds.fLeft -= DISTANCE_FIELD_PAD;
|
||||
bounds.fRight += DISTANCE_FIELD_PAD;
|
||||
bounds.fTop -= DISTANCE_FIELD_PAD;
|
||||
bounds.fBottom += DISTANCE_FIELD_PAD;
|
||||
bounds.fLeft -= DISTANCE_FIELD_RANGE;
|
||||
bounds.fRight += DISTANCE_FIELD_RANGE;
|
||||
bounds.fTop -= DISTANCE_FIELD_RANGE;
|
||||
bounds.fBottom += DISTANCE_FIELD_RANGE;
|
||||
}
|
||||
#endif
|
||||
glyph->init(packed, bounds);
|
||||
|
|
@ -294,15 +295,13 @@ bool GrTextStrike::addGlyphToAtlas(GrGlyph* glyph, GrFontScaler* scaler) {
|
|||
GrPlot* plot;
|
||||
#if SK_DISTANCEFIELD_FONTS
|
||||
if (fUseDistanceField) {
|
||||
SkASSERT(1 == bytesPerPixel);
|
||||
|
||||
// we've already expanded the glyph dimensions to match the final size
|
||||
// but must shrink back down to get the packed glyph data
|
||||
int dfWidth = glyph->width();
|
||||
int dfHeight = glyph->height();
|
||||
int width = dfWidth - 2*DISTANCE_FIELD_PAD;
|
||||
int height = dfHeight - 2*DISTANCE_FIELD_PAD;
|
||||
size_t stride = width*bytesPerPixel;
|
||||
int width = dfWidth - 2*DISTANCE_FIELD_RANGE;
|
||||
int height = dfHeight - 2*DISTANCE_FIELD_RANGE;
|
||||
int stride = width*bytesPerPixel;
|
||||
|
||||
size_t size = width * height * bytesPerPixel;
|
||||
SkAutoSMalloc<1024> storage(size);
|
||||
|
|
@ -314,14 +313,20 @@ bool GrTextStrike::addGlyphToAtlas(GrGlyph* glyph, GrFontScaler* scaler) {
|
|||
size_t dfSize = dfWidth * dfHeight * bytesPerPixel;
|
||||
SkAutoSMalloc<1024> dfStorage(dfSize);
|
||||
|
||||
// copy glyph into distance field storage
|
||||
if (1 == bytesPerPixel) {
|
||||
(void) SkGenerateDistanceFieldFromImage((unsigned char*)dfStorage.get(),
|
||||
(unsigned char*)storage.get(),
|
||||
width, height, DISTANCE_FIELD_RANGE);
|
||||
} else {
|
||||
// TODO: Fix color emoji
|
||||
// for now, copy glyph into distance field storage
|
||||
// this is not correct, but it won't crash
|
||||
sk_bzero(dfStorage.get(), dfSize);
|
||||
|
||||
unsigned char* ptr = (unsigned char*) storage.get();
|
||||
unsigned char* dfPtr = (unsigned char*) dfStorage.get();
|
||||
size_t dfStride = dfWidth*bytesPerPixel;
|
||||
dfPtr += DISTANCE_FIELD_PAD*dfStride;
|
||||
dfPtr += DISTANCE_FIELD_PAD*bytesPerPixel;
|
||||
dfPtr += DISTANCE_FIELD_RANGE*dfStride;
|
||||
dfPtr += DISTANCE_FIELD_RANGE*bytesPerPixel;
|
||||
|
||||
for (int i = 0; i < height; ++i) {
|
||||
memcpy(dfPtr, ptr, stride);
|
||||
|
|
@ -329,55 +334,6 @@ bool GrTextStrike::addGlyphToAtlas(GrGlyph* glyph, GrFontScaler* scaler) {
|
|||
dfPtr += dfStride;
|
||||
ptr += stride;
|
||||
}
|
||||
|
||||
// generate distance field data
|
||||
SkAutoSMalloc<1024> distXStorage(dfWidth*dfHeight*sizeof(short));
|
||||
SkAutoSMalloc<1024> distYStorage(dfWidth*dfHeight*sizeof(short));
|
||||
SkAutoSMalloc<1024> outerDistStorage(dfWidth*dfHeight*sizeof(double));
|
||||
SkAutoSMalloc<1024> innerDistStorage(dfWidth*dfHeight*sizeof(double));
|
||||
SkAutoSMalloc<1024> gxStorage(dfWidth*dfHeight*sizeof(double));
|
||||
SkAutoSMalloc<1024> gyStorage(dfWidth*dfHeight*sizeof(double));
|
||||
|
||||
short* distX = (short*) distXStorage.get();
|
||||
short* distY = (short*) distYStorage.get();
|
||||
double* outerDist = (double*) outerDistStorage.get();
|
||||
double* innerDist = (double*) innerDistStorage.get();
|
||||
double* gx = (double*) gxStorage.get();
|
||||
double* gy = (double*) gyStorage.get();
|
||||
|
||||
dfPtr = (unsigned char*) dfStorage.get();
|
||||
EDTAA::computegradient(dfPtr, dfWidth, dfHeight, gx, gy);
|
||||
EDTAA::edtaa3(dfPtr, gx, gy, dfWidth, dfHeight, distX, distY, outerDist);
|
||||
|
||||
for (int i = 0; i < dfWidth*dfHeight; ++i) {
|
||||
*dfPtr = 255 - *dfPtr;
|
||||
dfPtr++;
|
||||
}
|
||||
dfPtr = (unsigned char*) dfStorage.get();
|
||||
sk_bzero(gx, sizeof(double)*dfWidth*dfHeight);
|
||||
sk_bzero(gy, sizeof(double)*dfWidth*dfHeight);
|
||||
EDTAA::computegradient(dfPtr, dfWidth, dfHeight, gx, gy);
|
||||
EDTAA::edtaa3(dfPtr, gx, gy, dfWidth, dfHeight, distX, distY, innerDist);
|
||||
|
||||
for (int i = 0; i < dfWidth*dfHeight; ++i) {
|
||||
unsigned char val;
|
||||
double outerval = outerDist[i];
|
||||
if (outerval < 0.0) {
|
||||
outerval = 0.0;
|
||||
}
|
||||
double innerval = innerDist[i];
|
||||
if (innerval < 0.0) {
|
||||
innerval = 0.0;
|
||||
}
|
||||
double dist = outerval - innerval;
|
||||
if (dist <= -DISTANCE_FIELD_RANGE) {
|
||||
val = 255;
|
||||
} else if (dist > DISTANCE_FIELD_RANGE) {
|
||||
val = 0;
|
||||
} else {
|
||||
val = (unsigned char)((DISTANCE_FIELD_RANGE-dist)*128.0/DISTANCE_FIELD_RANGE);
|
||||
}
|
||||
*dfPtr++ = val;
|
||||
}
|
||||
|
||||
// copy to atlas
|
||||
|
|
|
|||
|
|
@ -1,21 +0,0 @@
|
|||
The MIT License (MIT)
|
||||
|
||||
Copyright (c) 2009-2012 Stefan Gustavson (stefan.gustavson@gmail.com)
|
||||
|
||||
Permission is hereby granted, free of charge, to any person obtaining a copy
|
||||
of this software and associated documentation files (the "Software"), to deal
|
||||
in the Software without restriction, including without limitation the rights
|
||||
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||||
copies of the Software, and to permit persons to whom the Software is
|
||||
furnished to do so, subject to the following conditions:
|
||||
|
||||
The above copyright notice and this permission notice shall be included in
|
||||
all copies or substantial portions of the Software.
|
||||
|
||||
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||||
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||||
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
||||
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
||||
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
||||
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
||||
THE SOFTWARE.
|
||||
|
|
@ -1,35 +0,0 @@
|
|||
/*
|
||||
Permission is hereby granted, free of charge, to any person obtaining a copy
|
||||
of this software and associated documentation files (the "Software"), to deal
|
||||
in the Software without restriction, including without limitation the rights
|
||||
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||||
copies of the Software, and to permit persons to whom the Software is
|
||||
furnished to do so, subject to the following conditions:
|
||||
|
||||
The above copyright notice and this permission notice shall be included in
|
||||
all copies or substantial portions of the Software.
|
||||
|
||||
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||||
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||||
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
||||
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
||||
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
||||
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
||||
THE SOFTWARE.
|
||||
*/
|
||||
|
||||
#define EDTAA_UNSIGNED_CHAR_INPUT 1
|
||||
|
||||
namespace EDTAA {
|
||||
|
||||
#if EDTAA_UNSIGNED_CHAR_INPUT
|
||||
typedef unsigned char EdtaaImageType;
|
||||
#else
|
||||
typedef double EdtaaImageType;
|
||||
#endif
|
||||
|
||||
void computegradient(EdtaaImageType *img, int w, int h, double *gx, double *gy);
|
||||
void edtaa3(EdtaaImageType *img, double *gx, double *gy, int w, int h,
|
||||
short *distx, short *disty, double *dist);
|
||||
|
||||
}
|
||||
|
|
@ -1,586 +0,0 @@
|
|||
/*
|
||||
* edtaa3()
|
||||
*
|
||||
* Sweep-and-update Euclidean distance transform of an
|
||||
* image. Positive pixels are treated as object pixels,
|
||||
* zero or negative pixels are treated as background.
|
||||
* An attempt is made to treat antialiased edges correctly.
|
||||
* The input image must have pixels in the range [0,1],
|
||||
* and the antialiased image should be a box-filter
|
||||
* sampling of the ideal, crisp edge.
|
||||
* If the antialias region is more than 1 pixel wide,
|
||||
* the result from this transform will be inaccurate.
|
||||
*
|
||||
* By Stefan Gustavson (stefan.gustavson@gmail.com).
|
||||
*
|
||||
* Originally written in 1994, based on a verbal
|
||||
* description of the SSED8 algorithm published in the
|
||||
* PhD dissertation of Ingemar Ragnemalm. This is his
|
||||
* algorithm, I only implemented it in C.
|
||||
*
|
||||
* Updated in 2004 to treat border pixels correctly,
|
||||
* and cleaned up the code to improve readability.
|
||||
*
|
||||
* Updated in 2009 to handle anti-aliased edges.
|
||||
*
|
||||
* Updated in 2011 to avoid a corner case infinite loop.
|
||||
*
|
||||
* Updated 2012 to change license from LGPL to MIT.
|
||||
*/
|
||||
|
||||
/*
|
||||
Copyright (C) 2009-2012 Stefan Gustavson (stefan.gustavson@gmail.com)
|
||||
The code in this file is distributed under the MIT license:
|
||||
|
||||
Permission is hereby granted, free of charge, to any person obtaining a copy
|
||||
of this software and associated documentation files (the "Software"), to deal
|
||||
in the Software without restriction, including without limitation the rights
|
||||
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||||
copies of the Software, and to permit persons to whom the Software is
|
||||
furnished to do so, subject to the following conditions:
|
||||
|
||||
The above copyright notice and this permission notice shall be included in
|
||||
all copies or substantial portions of the Software.
|
||||
|
||||
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||||
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||||
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
||||
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
||||
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
||||
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
||||
THE SOFTWARE.
|
||||
*/
|
||||
|
||||
#include "edtaa3.h"
|
||||
|
||||
#include <math.h>
|
||||
|
||||
#if EDTAA_UNSIGNED_CHAR_INPUT
|
||||
#define IMG(i) ((double)(img[i] & 0xff)/256.0)
|
||||
#else
|
||||
#define IMG(i) (img[i])
|
||||
#endif
|
||||
|
||||
namespace EDTAA {
|
||||
|
||||
/*
|
||||
* Compute the local gradient at edge pixels using convolution filters.
|
||||
* The gradient is computed only at edge pixels. At other places in the
|
||||
* image, it is never used, and it's mostly zero anyway.
|
||||
*/
|
||||
void computegradient(EdtaaImageType *img, int w, int h, double *gx, double *gy)
|
||||
{
|
||||
int i,j,k;
|
||||
double glength;
|
||||
#define SQRT2 1.4142136
|
||||
for(i = 1; i < h-1; i++) { // Avoid edges where the kernels would spill over
|
||||
for(j = 1; j < w-1; j++) {
|
||||
k = i*w + j;
|
||||
if((IMG(k)>0.0) && (IMG(k)<1.0)) { // Compute gradient for edge pixels only
|
||||
gx[k] = -IMG(k-w-1) - SQRT2*IMG(k-1) - IMG(k+w-1) + IMG(k-w+1) + SQRT2*IMG(k+1) + IMG(k+w+1);
|
||||
gy[k] = -IMG(k-w-1) - SQRT2*IMG(k-w) - IMG(k+w-1) + IMG(k-w+1) + SQRT2*IMG(k+w) + IMG(k+w+1);
|
||||
glength = gx[k]*gx[k] + gy[k]*gy[k];
|
||||
if(glength > 0.0) { // Avoid division by zero
|
||||
glength = sqrt(glength);
|
||||
gx[k]=gx[k]/glength;
|
||||
gy[k]=gy[k]/glength;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
// TODO: Compute reasonable values for gx, gy also around the image edges.
|
||||
// (These are zero now, which reduces the accuracy for a 1-pixel wide region
|
||||
// around the image edge.) 2x2 kernels would be suitable for this.
|
||||
}
|
||||
|
||||
/*
|
||||
* A somewhat tricky function to approximate the distance to an edge in a
|
||||
* certain pixel, with consideration to either the local gradient (gx,gy)
|
||||
* or the direction to the pixel (dx,dy) and the pixel greyscale value a.
|
||||
* The latter alternative, using (dx,dy), is the metric used by edtaa2().
|
||||
* Using a local estimate of the edge gradient (gx,gy) yields much better
|
||||
* accuracy at and near edges, and reduces the error even at distant pixels
|
||||
* provided that the gradient direction is accurately estimated.
|
||||
*/
|
||||
static double edgedf(double gx, double gy, double a)
|
||||
{
|
||||
double df, glength, temp, a1;
|
||||
|
||||
if ((gx == 0) || (gy == 0)) { // Either A) gu or gv are zero, or B) both
|
||||
df = 0.5-a; // Linear approximation is A) correct or B) a fair guess
|
||||
} else {
|
||||
glength = sqrt(gx*gx + gy*gy);
|
||||
if(glength>0) {
|
||||
gx = gx/glength;
|
||||
gy = gy/glength;
|
||||
}
|
||||
/* Everything is symmetric wrt sign and transposition,
|
||||
* so move to first octant (gx>=0, gy>=0, gx>=gy) to
|
||||
* avoid handling all possible edge directions.
|
||||
*/
|
||||
gx = fabs(gx);
|
||||
gy = fabs(gy);
|
||||
if(gx<gy) {
|
||||
temp = gx;
|
||||
gx = gy;
|
||||
gy = temp;
|
||||
}
|
||||
a1 = 0.5*gy/gx;
|
||||
if (a < a1) { // 0 <= a < a1
|
||||
df = 0.5*(gx + gy) - sqrt(2.0*gx*gy*a);
|
||||
} else if (a < (1.0-a1)) { // a1 <= a <= 1-a1
|
||||
df = (0.5-a)*gx;
|
||||
} else { // 1-a1 < a <= 1
|
||||
df = -0.5*(gx + gy) + sqrt(2.0*gx*gy*(1.0-a));
|
||||
}
|
||||
}
|
||||
return df;
|
||||
}
|
||||
|
||||
static double distaa3(EdtaaImageType *img, double *gximg, double *gyimg, int w, int c, int xc, int yc, int xi, int yi)
|
||||
{
|
||||
double di, df, dx, dy, gx, gy, a;
|
||||
int closest;
|
||||
|
||||
closest = c-xc-yc*w; // Index to the edge pixel pointed to from c
|
||||
a = IMG(closest); // Grayscale value at the edge pixel
|
||||
gx = gximg[closest]; // X gradient component at the edge pixel
|
||||
gy = gyimg[closest]; // Y gradient component at the edge pixel
|
||||
|
||||
if(a > 1.0) a = 1.0;
|
||||
if(a < 0.0) a = 0.0; // Clip grayscale values outside the range [0,1]
|
||||
if(a == 0.0) return 1000000.0; // Not an object pixel, return "very far" ("don't know yet")
|
||||
|
||||
dx = (double)xi;
|
||||
dy = (double)yi;
|
||||
di = sqrt(dx*dx + dy*dy); // Length of integer vector, like a traditional EDT
|
||||
if(di==0) { // Use local gradient only at edges
|
||||
// Estimate based on local gradient only
|
||||
df = edgedf(gx, gy, a);
|
||||
} else {
|
||||
// Estimate gradient based on direction to edge (accurate for large di)
|
||||
df = edgedf(dx, dy, a);
|
||||
}
|
||||
return di + df; // Same metric as edtaa2, except at edges (where di=0)
|
||||
}
|
||||
|
||||
// Shorthand macro: add ubiquitous parameters dist, gx, gy, img and w and call distaa3()
|
||||
#define DISTAA(c,xc,yc,xi,yi) (distaa3(img, gx, gy, w, c, xc, yc, xi, yi))
|
||||
|
||||
void edtaa3(EdtaaImageType *img, double *gx, double *gy, int w, int h, short *distx, short *disty, double *dist)
|
||||
{
|
||||
int x, y, i, c;
|
||||
int offset_u, offset_ur, offset_r, offset_rd,
|
||||
offset_d, offset_dl, offset_l, offset_lu;
|
||||
double olddist, newdist;
|
||||
int cdistx, cdisty, newdistx, newdisty;
|
||||
int changed;
|
||||
double epsilon = 1e-3;
|
||||
double a;
|
||||
|
||||
/* Initialize index offsets for the current image width */
|
||||
offset_u = -w;
|
||||
offset_ur = -w+1;
|
||||
offset_r = 1;
|
||||
offset_rd = w+1;
|
||||
offset_d = w;
|
||||
offset_dl = w-1;
|
||||
offset_l = -1;
|
||||
offset_lu = -w-1;
|
||||
|
||||
/* Initialize the distance images */
|
||||
for(i=0; i<w*h; i++) {
|
||||
distx[i] = 0; // At first, all pixels point to
|
||||
disty[i] = 0; // themselves as the closest known.
|
||||
a = IMG(i);
|
||||
if(a <= 0.0)
|
||||
{
|
||||
dist[i]= 1000000.0; // Big value, means "not set yet"
|
||||
}
|
||||
else if (a<1.0) {
|
||||
dist[i] = edgedf(gx[i], gy[i], a); // Gradient-assisted estimate
|
||||
}
|
||||
else {
|
||||
dist[i]= 0.0; // Inside the object
|
||||
}
|
||||
}
|
||||
|
||||
/* Perform the transformation */
|
||||
do
|
||||
{
|
||||
changed = 0;
|
||||
|
||||
/* Scan rows, except first row */
|
||||
for(y=1; y<h; y++)
|
||||
{
|
||||
|
||||
/* move index to leftmost pixel of current row */
|
||||
i = y*w;
|
||||
|
||||
/* scan right, propagate distances from above & left */
|
||||
|
||||
/* Leftmost pixel is special, has no left neighbors */
|
||||
olddist = dist[i];
|
||||
if(olddist > 0) // If non-zero distance or not set yet
|
||||
{
|
||||
c = i + offset_u; // Index of candidate for testing
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_ur;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
i++;
|
||||
|
||||
/* Middle pixels have all neighbors */
|
||||
for(x=1; x<w-1; x++, i++)
|
||||
{
|
||||
olddist = dist[i];
|
||||
if(olddist <= 0) continue; // No need to update further
|
||||
|
||||
c = i+offset_l;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_lu;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_u;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_ur;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
|
||||
/* Rightmost pixel of row is special, has no right neighbors */
|
||||
olddist = dist[i];
|
||||
if(olddist > 0) // If not already zero distance
|
||||
{
|
||||
c = i+offset_l;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_lu;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_u;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty+1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
|
||||
/* Move index to second rightmost pixel of current row. */
|
||||
/* Rightmost pixel is skipped, it has no right neighbor. */
|
||||
i = y*w + w-2;
|
||||
|
||||
/* scan left, propagate distance from right */
|
||||
for(x=w-2; x>=0; x--, i--)
|
||||
{
|
||||
olddist = dist[i];
|
||||
if(olddist <= 0) continue; // Already zero distance
|
||||
|
||||
c = i+offset_r;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* Scan rows in reverse order, except last row */
|
||||
for(y=h-2; y>=0; y--)
|
||||
{
|
||||
/* move index to rightmost pixel of current row */
|
||||
i = y*w + w-1;
|
||||
|
||||
/* Scan left, propagate distances from below & right */
|
||||
|
||||
/* Rightmost pixel is special, has no right neighbors */
|
||||
olddist = dist[i];
|
||||
if(olddist > 0) // If not already zero distance
|
||||
{
|
||||
c = i+offset_d;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_dl;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
i--;
|
||||
|
||||
/* Middle pixels have all neighbors */
|
||||
for(x=w-2; x>0; x--, i--)
|
||||
{
|
||||
olddist = dist[i];
|
||||
if(olddist <= 0) continue; // Already zero distance
|
||||
|
||||
c = i+offset_r;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_rd;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_d;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_dl;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
/* Leftmost pixel is special, has no left neighbors */
|
||||
olddist = dist[i];
|
||||
if(olddist > 0) // If not already zero distance
|
||||
{
|
||||
c = i+offset_r;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_rd;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx-1;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
olddist=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
|
||||
c = i+offset_d;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx;
|
||||
newdisty = cdisty-1;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
|
||||
/* Move index to second leftmost pixel of current row. */
|
||||
/* Leftmost pixel is skipped, it has no left neighbor. */
|
||||
i = y*w + 1;
|
||||
for(x=1; x<w; x++, i++)
|
||||
{
|
||||
/* scan right, propagate distance from left */
|
||||
olddist = dist[i];
|
||||
if(olddist <= 0) continue; // Already zero distance
|
||||
|
||||
c = i+offset_l;
|
||||
cdistx = distx[c];
|
||||
cdisty = disty[c];
|
||||
newdistx = cdistx+1;
|
||||
newdisty = cdisty;
|
||||
newdist = DISTAA(c, cdistx, cdisty, newdistx, newdisty);
|
||||
if(newdist < olddist-epsilon)
|
||||
{
|
||||
distx[i]=newdistx;
|
||||
disty[i]=newdisty;
|
||||
dist[i]=newdist;
|
||||
changed = 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
while(changed); // Sweep until no more updates are made
|
||||
|
||||
/* The transformation is completed. */
|
||||
|
||||
}
|
||||
|
||||
} // namespace EDTAA
|
||||
Загрузка…
Ссылка в новой задаче