WebCore/platform/graphics/win/FontCGWin.cpp

   1 /*
   2  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "Font.h"
  28
  29 #include "AffineTransform.h"
  30 #include "FloatConversion.h"
  31 #include "GlyphBuffer.h"
  32 #include "GraphicsContext.h"
  33 #include "IntRect.h"
  34 #include "SimpleFontData.h"
  35 #include "UniscribeController.h"
  36 #include "WebCoreTextRenderer.h"
  37 #include <ApplicationServices/ApplicationServices.h>
  38 #include <WebKitSystemInterface/WebKitSystemInterface.h>
  39 #include <wtf/MathExtras.h>
  40
  41 namespace WebCore {
  42
  43 const int syntheticObliqueAngle = 14;
  44
  45 static inline CGFloat toCGFloat(FIXED f)
  46 {
  47     return f.value + f.fract / CGFloat(65536.0);
  48 }
  49
  50 static CGPathRef createPathForGlyph(HDC hdc, Glyph glyph)
  51 {
  52     CGMutablePathRef path = CGPathCreateMutable();
  53
  54     static const MAT2 identity = { 0, 1,  0, 0,  0, 0,  0, 1 };
  55     GLYPHMETRICS glyphMetrics;
  56     // GGO_NATIVE matches the outline perfectly when Windows font smoothing is off.
  57     // GGO_NATIVE | GGO_UNHINTED does not match perfectly either when Windows font smoothing is on or off.
  58     DWORD outlineLength = GetGlyphOutline(hdc, glyph, GGO_GLYPH_INDEX | GGO_NATIVE, &glyphMetrics, 0, 0, &identity);
  59     ASSERT(outlineLength >= 0);
  60     if (outlineLength < 0)
  61         return path;
  62
  63     Vector<UInt8> outline(outlineLength);
  64     GetGlyphOutline(hdc, glyph, GGO_GLYPH_INDEX | GGO_NATIVE, &glyphMetrics, outlineLength, outline.data(), &identity);
  65
  66     unsigned offset = 0;
  67     while (offset < outlineLength) {
  68         LPTTPOLYGONHEADER subpath = reinterpret_cast<LPTTPOLYGONHEADER>(outline.data() + offset);
  69         ASSERT(subpath->dwType == TT_POLYGON_TYPE);
  70         if (subpath->dwType != TT_POLYGON_TYPE)
  71             return path;
  72
  73         CGPathMoveToPoint(path, 0, toCGFloat(subpath->pfxStart.x), toCGFloat(subpath->pfxStart.y));
  74
  75         unsigned subpathOffset = sizeof(*subpath);
  76         while (subpathOffset < subpath->cb) {
  77             LPTTPOLYCURVE segment = reinterpret_cast<LPTTPOLYCURVE>(reinterpret_cast<UInt8*>(subpath) + subpathOffset);
  78             switch (segment->wType) {
  79                 case TT_PRIM_LINE:
  80                     for (unsigned i = 0; i < segment->cpfx; i++)
  81                         CGPathAddLineToPoint(path, 0, toCGFloat(segment->apfx[i].x), toCGFloat(segment->apfx[i].y));
  82                     break;
  83
  84                 case TT_PRIM_QSPLINE:
  85                     for (unsigned i = 0; i < segment->cpfx; i++) {
  86                         CGFloat x = toCGFloat(segment->apfx[i].x);
  87                         CGFloat y = toCGFloat(segment->apfx[i].y);
  88                         CGFloat cpx;
  89                         CGFloat cpy;
  90
  91                         if (i == segment->cpfx - 2) {
  92                             cpx = toCGFloat(segment->apfx[i + 1].x);
  93                             cpy = toCGFloat(segment->apfx[i + 1].y);
  94                             i++;
  95                         } else {
  96                             cpx = (toCGFloat(segment->apfx[i].x) + toCGFloat(segment->apfx[i + 1].x)) / 2;
  97                             cpy = (toCGFloat(segment->apfx[i].y) + toCGFloat(segment->apfx[i + 1].y)) / 2;
  98                         }
  99
 100                         CGPathAddQuadCurveToPoint(path, 0, x, y, cpx, cpy);
 101                     }
 102                     break;
 103
 104                 case TT_PRIM_CSPLINE:
 105                     for (unsigned i = 0; i < segment->cpfx; i += 3) {
 106                         CGFloat cp1x = toCGFloat(segment->apfx[i].x);
 107                         CGFloat cp1y = toCGFloat(segment->apfx[i].y);
 108                         CGFloat cp2x = toCGFloat(segment->apfx[i + 1].x);
 109                         CGFloat cp2y = toCGFloat(segment->apfx[i + 1].y);
 110                         CGFloat x = toCGFloat(segment->apfx[i + 2].x);
 111                         CGFloat y = toCGFloat(segment->apfx[i + 2].y);
 112
 113                         CGPathAddCurveToPoint(path, 0, cp1x, cp1y, cp2x, cp2y, x, y);
 114                     }
 115                     break;
 116
 117                 default:
 118                     ASSERT_NOT_REACHED();
 119                     return path;
 120             }
 121
 122             subpathOffset += sizeof(*segment) + (segment->cpfx - 1) * sizeof(segment->apfx[0]);
 123         }
 124         CGPathCloseSubpath(path);
 125         offset += subpath->cb;
 126     }
 127     return path;
 128 }
 129
 130 static void drawGDIGlyphs(GraphicsContext* graphicsContext, const SimpleFontData* font, const GlyphBuffer& glyphBuffer,
 131                       int from, int numGlyphs, const FloatPoint& point)
 132 {
 133     Color fillColor = graphicsContext->fillColor();
 134
 135     bool drawIntoBitmap = false;
 136     int drawingMode = graphicsContext->textDrawingMode();
 137     if (drawingMode == cTextFill) {
 138         if (!fillColor.alpha())
 139             return;
 140
 141         drawIntoBitmap = fillColor.alpha() != 255 || graphicsContext->inTransparencyLayer();
 142         if (!drawIntoBitmap) {
 143             FloatSize offset;
 144             float blur;
 145             Color color;
 146             graphicsContext->getShadow(offset, blur, color);
 147             drawIntoBitmap = offset.width() || offset.height() || blur;
 148         }
 149     }
 150
 151     // We have to convert CG's two-dimensional floating point advances to just horizontal integer advances.
 152     Vector<int, 2048> gdiAdvances;
 153     int totalWidth = 0;
 154     for (int i = 0; i < numGlyphs; i++) {
 155         gdiAdvances.append(lroundf(glyphBuffer.advanceAt(from + i)));
 156         totalWidth += gdiAdvances[i];
 157     }
 158
 159     HDC hdc = 0;
 160     OwnPtr<GraphicsContext::WindowsBitmap> bitmap;
 161     IntRect textRect;
 162     if (!drawIntoBitmap)
 163         hdc = graphicsContext->getWindowsContext(textRect, true, false);
 164     if (!hdc) {
 165         drawIntoBitmap = true;
 166         // We put slop into this rect, since glyphs can overflow the ascent/descent bounds and the left/right edges.
 167         // FIXME: Can get glyphs' optical bounds (even from CG) to get this right.
 168         int lineGap = font->lineGap();
 169         textRect = IntRect(point.x() - (font->ascent() + font->descent()) / 2, point.y() - font->ascent() - lineGap, totalWidth + font->ascent() + font->descent(), font->lineSpacing());
 170         bitmap.set(graphicsContext->createWindowsBitmap(textRect.size()));
 171         memset(bitmap->buffer(), 255, bitmap->bufferLength());
 172         hdc = bitmap->hdc();
 173
 174         XFORM xform;
 175         xform.eM11 = 1.0f;
 176         xform.eM12 = 0.0f;
 177         xform.eM21 = 0.0f;
 178         xform.eM22 = 1.0f;
 179         xform.eDx = -textRect.x();
 180         xform.eDy = -textRect.y();
 181         SetWorldTransform(hdc, &xform);
 182     }
 183
 184     SelectObject(hdc, font->platformData().hfont());
 185
 186     // Set the correct color.
 187     if (drawIntoBitmap)
 188         SetTextColor(hdc, RGB(0, 0, 0));
 189     else
 190         SetTextColor(hdc, RGB(fillColor.red(), fillColor.green(), fillColor.blue()));
 191
 192     SetBkMode(hdc, TRANSPARENT);
 193     SetTextAlign(hdc, TA_LEFT | TA_BASELINE);
 194
 195     // Uniscribe gives us offsets to help refine the positioning of combining glyphs.
 196     FloatSize translation = glyphBuffer.offsetAt(from);
 197     if (translation.width() || translation.height()) {
 198         XFORM xform;
 199         xform.eM11 = 1.0;
 200         xform.eM12 = 0;
 201         xform.eM21 = 0;
 202         xform.eM22 = 1.0;
 203         xform.eDx = translation.width();
 204         xform.eDy = translation.height();
 205         ModifyWorldTransform(hdc, &xform, MWT_LEFTMULTIPLY);
 206     }
 207
 208     if (drawingMode == cTextFill) {
 209         XFORM xform;
 210         xform.eM11 = 1.0;
 211         xform.eM12 = 0;
 212         xform.eM21 = font->platformData().syntheticOblique() ? -tanf(syntheticObliqueAngle * piFloat / 180.0f) : 0;
 213         xform.eM22 = 1.0;
 214         xform.eDx = point.x();
 215         xform.eDy = point.y();
 216         ModifyWorldTransform(hdc, &xform, MWT_LEFTMULTIPLY);
 217         ExtTextOut(hdc, 0, 0, ETO_GLYPH_INDEX, 0, reinterpret_cast<const WCHAR*>(glyphBuffer.glyphs(from)), numGlyphs, gdiAdvances.data());
 218         if (font->syntheticBoldOffset()) {
 219             xform.eM21 = 0;
 220             xform.eDx = font->syntheticBoldOffset();
 221             xform.eDy = 0;
 222             ModifyWorldTransform(hdc, &xform, MWT_LEFTMULTIPLY);
 223             ExtTextOut(hdc, 0, 0, ETO_GLYPH_INDEX, 0, reinterpret_cast<const WCHAR*>(glyphBuffer.glyphs(from)), numGlyphs, gdiAdvances.data());
 224         }
 225     } else {
 226         XFORM xform;
 227         GetWorldTransform(hdc, &xform);
 228         AffineTransform hdcTransform(xform.eM11, xform.eM21, xform.eM12, xform.eM22, xform.eDx, xform.eDy);
 229         CGAffineTransform initialGlyphTransform = hdcTransform.isInvertible() ? hdcTransform.inverse() : CGAffineTransformIdentity;
 230         if (font->platformData().syntheticOblique())
 231             initialGlyphTransform = CGAffineTransformConcat(initialGlyphTransform, CGAffineTransformMake(1, 0, tanf(syntheticObliqueAngle * piFloat / 180.0f), 1, 0, 0));
 232         initialGlyphTransform.tx = 0;
 233         initialGlyphTransform.ty = 0;
 234         CGContextRef cgContext = graphicsContext->platformContext();
 235
 236         CGContextSaveGState(cgContext);
 237
 238         BOOL fontSmoothingEnabled = false;
 239         SystemParametersInfo(SPI_GETFONTSMOOTHING, 0, &fontSmoothingEnabled, 0);
 240         CGContextSetShouldAntialias(cgContext, fontSmoothingEnabled);
 241
 242         CGContextScaleCTM(cgContext, 1.0, -1.0);
 243         CGContextTranslateCTM(cgContext, point.x() + glyphBuffer.offsetAt(from).width(), -(point.y() + glyphBuffer.offsetAt(from).height()));
 244
 245         for (unsigned i = 0; i < numGlyphs; ++i) {
 246             RetainPtr<CGPathRef> glyphPath(AdoptCF, createPathForGlyph(hdc, glyphBuffer.glyphAt(from + i)));
 247             CGContextSaveGState(cgContext);
 248             CGContextConcatCTM(cgContext, initialGlyphTransform);
 249
 250             if (drawingMode & cTextFill) {
 251                 CGContextAddPath(cgContext, glyphPath.get());
 252                 CGContextFillPath(cgContext);
 253                 if (font->syntheticBoldOffset()) {
 254                     CGContextTranslateCTM(cgContext, font->syntheticBoldOffset(), 0);
 255                     CGContextAddPath(cgContext, glyphPath.get());
 256                     CGContextFillPath(cgContext);
 257                     CGContextTranslateCTM(cgContext, -font->syntheticBoldOffset(), 0);
 258                 }
 259             }
 260             if (drawingMode & cTextStroke) {
 261                 CGContextAddPath(cgContext, glyphPath.get());
 262                 CGContextStrokePath(cgContext);
 263                 if (font->syntheticBoldOffset()) {
 264                     CGContextTranslateCTM(cgContext, font->syntheticBoldOffset(), 0);
 265                     CGContextAddPath(cgContext, glyphPath.get());
 266                     CGContextStrokePath(cgContext);
 267                     CGContextTranslateCTM(cgContext, -font->syntheticBoldOffset(), 0);
 268                 }
 269             }
 270
 271             CGContextRestoreGState(cgContext);
 272             CGContextTranslateCTM(cgContext, gdiAdvances[i], 0);
 273         }
 274
 275         CGContextRestoreGState(cgContext);
 276     }
 277
 278     if (drawIntoBitmap) {
 279         UInt8* buffer = bitmap->buffer();
 280         unsigned bufferLength = bitmap->bufferLength();
 281         for (unsigned i = 0; i < bufferLength; i += 4) {
 282             // Use green, which is always in the middle.
 283             UInt8 alpha = (255 - buffer[i + 1]) * fillColor.alpha() / 255;
 284             buffer[i] = fillColor.blue();
 285             buffer[i + 1] = fillColor.green();
 286             buffer[i + 2] = fillColor.red();
 287             buffer[i + 3] = alpha;
 288         }
 289         graphicsContext->drawWindowsBitmap(bitmap.get(), textRect.topLeft());
 290     } else
 291         graphicsContext->releaseWindowsContext(hdc, textRect, true, false);
 292 }
 293
 294 void Font::drawGlyphs(GraphicsContext* graphicsContext, const SimpleFontData* font, const GlyphBuffer& glyphBuffer,
 295                       int from, int numGlyphs, const FloatPoint& point) const
 296 {
 297     CGContextRef cgContext = graphicsContext->platformContext();
 298     bool shouldUseFontSmoothing = WebCoreShouldUseFontSmoothing();
 299
 300     switch(fontDescription().fontSmoothing()) {
 301     case Antialiased: {
 302         graphicsContext->setShouldAntialias(true);
 303         shouldUseFontSmoothing = false;
 304         break;
 305     }
 306     case SubpixelAntialiased: {
 307         graphicsContext->setShouldAntialias(true);
 308         shouldUseFontSmoothing = true;
 309         break;
 310     }
 311     case NoSmoothing: {
 312         graphicsContext->setShouldAntialias(false);
 313         shouldUseFontSmoothing = false;
 314         break;
 315     }
 316     case AutoSmoothing: {
 317         // For the AutoSmooth case, don't do anything! Keep the default settings.
 318         break;
 319     }
 320     default:
 321         ASSERT_NOT_REACHED();
 322     }
 323
 324     if (font->platformData().useGDI() && !shouldUseFontSmoothing) {
 325         drawGDIGlyphs(graphicsContext, font, glyphBuffer, from, numGlyphs, point);
 326         return;
 327     }
 328
 329     uint32_t oldFontSmoothingStyle = wkSetFontSmoothingStyle(cgContext, shouldUseFontSmoothing);
 330
 331     const FontPlatformData& platformData = font->platformData();
 332
 333     CGContextSetFont(cgContext, platformData.cgFont());
 334
 335     CGAffineTransform matrix = CGAffineTransformIdentity;
 336     matrix.b = -matrix.b;
 337     matrix.d = -matrix.d;
 338
 339     if (platformData.syntheticOblique()) {
 340         static float skew = -tanf(syntheticObliqueAngle * piFloat / 180.0f);
 341         matrix = CGAffineTransformConcat(matrix, CGAffineTransformMake(1, 0, skew, 1, 0, 0));
 342     }
 343
 344     CGContextSetTextMatrix(cgContext, matrix);
 345
 346     // Uniscribe gives us offsets to help refine the positioning of combining glyphs.
 347     FloatSize translation = glyphBuffer.offsetAt(from);
 348
 349     CGContextSetFontSize(cgContext, platformData.size());
 350     wkSetCGContextFontRenderingStyle(cgContext, font->isSystemFont(), false, font->platformData().useGDI());
 351
 352     FloatSize shadowOffset;
 353     float shadowBlur;
 354     Color shadowColor;
 355     graphicsContext->getShadow(shadowOffset, shadowBlur, shadowColor);
 356
 357     bool hasSimpleShadow = graphicsContext->textDrawingMode() == cTextFill && shadowColor.isValid() && !shadowBlur;
 358     if (hasSimpleShadow) {
 359         // Paint simple shadows ourselves instead of relying on CG shadows, to avoid losing subpixel antialiasing.
 360         graphicsContext->clearShadow();
 361         Color fillColor = graphicsContext->fillColor();
 362         Color shadowFillColor(shadowColor.red(), shadowColor.green(), shadowColor.blue(), shadowColor.alpha() * fillColor.alpha() / 255);
 363         graphicsContext->setFillColor(shadowFillColor, ColorSpaceDeviceRGB);
 364         CGContextSetTextPosition(cgContext, point.x() + translation.width() + shadowOffset.width(), point.y() + translation.height() + shadowOffset.height());
 365         CGContextShowGlyphsWithAdvances(cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
 366         if (font->syntheticBoldOffset()) {
 367             CGContextSetTextPosition(cgContext, point.x() + translation.width() + shadowOffset.width() + font->syntheticBoldOffset(), point.y() + translation.height() + shadowOffset.height());
 368             CGContextShowGlyphsWithAdvances(cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
 369         }
 370         graphicsContext->setFillColor(fillColor, ColorSpaceDeviceRGB);
 371     }
 372
 373     CGContextSetTextPosition(cgContext, point.x() + translation.width(), point.y() + translation.height());
 374     CGContextShowGlyphsWithAdvances(cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
 375     if (font->syntheticBoldOffset()) {
 376         CGContextSetTextPosition(cgContext, point.x() + translation.width() + font->syntheticBoldOffset(), point.y() + translation.height());
 377         CGContextShowGlyphsWithAdvances(cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
 378     }
 379
 380     if (hasSimpleShadow)
 381         graphicsContext->setShadow(shadowOffset, shadowBlur, shadowColor, ColorSpaceDeviceRGB);
 382
 383     wkRestoreFontSmoothingStyle(cgContext, oldFontSmoothingStyle);
 384 }
 385
 386 }