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      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     TextDrawingModeFlags drawingMode = graphicsContext->textDrawingMode();
    137     if (drawingMode == TextModeFill) {
    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             ColorSpace shadowColorSpace;
    147 
    148             graphicsContext->getShadow(offset, blur, color, shadowColorSpace);
    149             drawIntoBitmap = offset.width() || offset.height() || blur;
    150         }
    151     }
    152 
    153     // We have to convert CG's two-dimensional floating point advances to just horizontal integer advances.
    154     Vector<int, 2048> gdiAdvances;
    155     int totalWidth = 0;
    156     for (int i = 0; i < numGlyphs; i++) {
    157         gdiAdvances.append(lroundf(glyphBuffer.advanceAt(from + i)));
    158         totalWidth += gdiAdvances[i];
    159     }
    160 
    161     HDC hdc = 0;
    162     OwnPtr<GraphicsContext::WindowsBitmap> bitmap;
    163     IntRect textRect;
    164     if (!drawIntoBitmap)
    165         hdc = graphicsContext->getWindowsContext(textRect, true, false);
    166     if (!hdc) {
    167         drawIntoBitmap = true;
    168         // We put slop into this rect, since glyphs can overflow the ascent/descent bounds and the left/right edges.
    169         // FIXME: Can get glyphs' optical bounds (even from CG) to get this right.
    170         const FontMetrics& fontMetrics = font->fontMetrics();
    171         int lineGap = fontMetrics.lineGap();
    172         textRect = IntRect(point.x() - (fontMetrics.ascent() + fontMetrics.descent()) / 2,
    173                            point.y() - fontMetrics.ascent() - lineGap,
    174                            totalWidth + fontMetrics.ascent() + fontMetrics.descent(),
    175                            fontMetrics.lineSpacing());
    176         bitmap.set(graphicsContext->createWindowsBitmap(textRect.size()));
    177         memset(bitmap->buffer(), 255, bitmap->bufferLength());
    178         hdc = bitmap->hdc();
    179 
    180         XFORM xform;
    181         xform.eM11 = 1.0f;
    182         xform.eM12 = 0.0f;
    183         xform.eM21 = 0.0f;
    184         xform.eM22 = 1.0f;
    185         xform.eDx = -textRect.x();
    186         xform.eDy = -textRect.y();
    187         SetWorldTransform(hdc, &xform);
    188     }
    189 
    190     SelectObject(hdc, font->platformData().hfont());
    191 
    192     // Set the correct color.
    193     if (drawIntoBitmap)
    194         SetTextColor(hdc, RGB(0, 0, 0));
    195     else
    196         SetTextColor(hdc, RGB(fillColor.red(), fillColor.green(), fillColor.blue()));
    197 
    198     SetBkMode(hdc, TRANSPARENT);
    199     SetTextAlign(hdc, TA_LEFT | TA_BASELINE);
    200 
    201     // Uniscribe gives us offsets to help refine the positioning of combining glyphs.
    202     FloatSize translation = glyphBuffer.offsetAt(from);
    203     if (translation.width() || translation.height()) {
    204         XFORM xform;
    205         xform.eM11 = 1.0;
    206         xform.eM12 = 0;
    207         xform.eM21 = 0;
    208         xform.eM22 = 1.0;
    209         xform.eDx = translation.width();
    210         xform.eDy = translation.height();
    211         ModifyWorldTransform(hdc, &xform, MWT_LEFTMULTIPLY);
    212     }
    213 
    214     if (drawingMode == TextModeFill) {
    215         XFORM xform;
    216         xform.eM11 = 1.0;
    217         xform.eM12 = 0;
    218         xform.eM21 = font->platformData().syntheticOblique() ? -tanf(syntheticObliqueAngle * piFloat / 180.0f) : 0;
    219         xform.eM22 = 1.0;
    220         xform.eDx = point.x();
    221         xform.eDy = point.y();
    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         if (font->syntheticBoldOffset()) {
    225             xform.eM21 = 0;
    226             xform.eDx = font->syntheticBoldOffset();
    227             xform.eDy = 0;
    228             ModifyWorldTransform(hdc, &xform, MWT_LEFTMULTIPLY);
    229             ExtTextOut(hdc, 0, 0, ETO_GLYPH_INDEX, 0, reinterpret_cast<const WCHAR*>(glyphBuffer.glyphs(from)), numGlyphs, gdiAdvances.data());
    230         }
    231     } else {
    232         XFORM xform;
    233         GetWorldTransform(hdc, &xform);
    234         AffineTransform hdcTransform(xform.eM11, xform.eM21, xform.eM12, xform.eM22, xform.eDx, xform.eDy);
    235         CGAffineTransform initialGlyphTransform = hdcTransform.isInvertible() ? hdcTransform.inverse() : CGAffineTransformIdentity;
    236         if (font->platformData().syntheticOblique())
    237             initialGlyphTransform = CGAffineTransformConcat(initialGlyphTransform, CGAffineTransformMake(1, 0, tanf(syntheticObliqueAngle * piFloat / 180.0f), 1, 0, 0));
    238         initialGlyphTransform.tx = 0;
    239         initialGlyphTransform.ty = 0;
    240         CGContextRef cgContext = graphicsContext->platformContext();
    241 
    242         CGContextSaveGState(cgContext);
    243 
    244         BOOL fontSmoothingEnabled = false;
    245         SystemParametersInfo(SPI_GETFONTSMOOTHING, 0, &fontSmoothingEnabled, 0);
    246         CGContextSetShouldAntialias(cgContext, fontSmoothingEnabled);
    247 
    248         CGContextScaleCTM(cgContext, 1.0, -1.0);
    249         CGContextTranslateCTM(cgContext, point.x() + glyphBuffer.offsetAt(from).width(), -(point.y() + glyphBuffer.offsetAt(from).height()));
    250 
    251         for (unsigned i = 0; i < numGlyphs; ++i) {
    252             RetainPtr<CGPathRef> glyphPath(AdoptCF, createPathForGlyph(hdc, glyphBuffer.glyphAt(from + i)));
    253             CGContextSaveGState(cgContext);
    254             CGContextConcatCTM(cgContext, initialGlyphTransform);
    255 
    256             if (drawingMode & TextModeFill) {
    257                 CGContextAddPath(cgContext, glyphPath.get());
    258                 CGContextFillPath(cgContext);
    259                 if (font->syntheticBoldOffset()) {
    260                     CGContextTranslateCTM(cgContext, font->syntheticBoldOffset(), 0);
    261                     CGContextAddPath(cgContext, glyphPath.get());
    262                     CGContextFillPath(cgContext);
    263                     CGContextTranslateCTM(cgContext, -font->syntheticBoldOffset(), 0);
    264                 }
    265             }
    266             if (drawingMode & TextModeStroke) {
    267                 CGContextAddPath(cgContext, glyphPath.get());
    268                 CGContextStrokePath(cgContext);
    269                 if (font->syntheticBoldOffset()) {
    270                     CGContextTranslateCTM(cgContext, font->syntheticBoldOffset(), 0);
    271                     CGContextAddPath(cgContext, glyphPath.get());
    272                     CGContextStrokePath(cgContext);
    273                     CGContextTranslateCTM(cgContext, -font->syntheticBoldOffset(), 0);
    274                 }
    275             }
    276 
    277             CGContextRestoreGState(cgContext);
    278             CGContextTranslateCTM(cgContext, gdiAdvances[i], 0);
    279         }
    280 
    281         CGContextRestoreGState(cgContext);
    282     }
    283 
    284     if (drawIntoBitmap) {
    285         UInt8* buffer = bitmap->buffer();
    286         unsigned bufferLength = bitmap->bufferLength();
    287         for (unsigned i = 0; i < bufferLength; i += 4) {
    288             // Use green, which is always in the middle.
    289             UInt8 alpha = (255 - buffer[i + 1]) * fillColor.alpha() / 255;
    290             buffer[i] = fillColor.blue();
    291             buffer[i + 1] = fillColor.green();
    292             buffer[i + 2] = fillColor.red();
    293             buffer[i + 3] = alpha;
    294         }
    295         graphicsContext->drawWindowsBitmap(bitmap.get(), textRect.location());
    296     } else
    297         graphicsContext->releaseWindowsContext(hdc, textRect, true, false);
    298 }
    299 
    300 void Font::drawGlyphs(GraphicsContext* graphicsContext, const SimpleFontData* font, const GlyphBuffer& glyphBuffer,
    301                       int from, int numGlyphs, const FloatPoint& point) const
    302 {
    303     CGContextRef cgContext = graphicsContext->platformContext();
    304     bool shouldUseFontSmoothing = WebCoreShouldUseFontSmoothing();
    305 
    306     switch(fontDescription().fontSmoothing()) {
    307     case Antialiased: {
    308         graphicsContext->setShouldAntialias(true);
    309         shouldUseFontSmoothing = false;
    310         break;
    311     }
    312     case SubpixelAntialiased: {
    313         graphicsContext->setShouldAntialias(true);
    314         shouldUseFontSmoothing = true;
    315         break;
    316     }
    317     case NoSmoothing: {
    318         graphicsContext->setShouldAntialias(false);
    319         shouldUseFontSmoothing = false;
    320         break;
    321     }
    322     case AutoSmoothing: {
    323         // For the AutoSmooth case, don't do anything! Keep the default settings.
    324         break;
    325     }
    326     default:
    327         ASSERT_NOT_REACHED();
    328     }
    329 
    330     if (font->platformData().useGDI() && !shouldUseFontSmoothing) {
    331         drawGDIGlyphs(graphicsContext, font, glyphBuffer, from, numGlyphs, point);
    332         return;
    333     }
    334 
    335     uint32_t oldFontSmoothingStyle = wkSetFontSmoothingStyle(cgContext, shouldUseFontSmoothing);
    336 
    337     const FontPlatformData& platformData = font->platformData();
    338 
    339     CGContextSetFont(cgContext, platformData.cgFont());
    340 
    341     CGAffineTransform matrix = CGAffineTransformIdentity;
    342     matrix.b = -matrix.b;
    343     matrix.d = -matrix.d;
    344 
    345     if (platformData.syntheticOblique()) {
    346         static float skew = -tanf(syntheticObliqueAngle * piFloat / 180.0f);
    347         matrix = CGAffineTransformConcat(matrix, CGAffineTransformMake(1, 0, skew, 1, 0, 0));
    348     }
    349 
    350     CGContextSetTextMatrix(cgContext, matrix);
    351 
    352     // Uniscribe gives us offsets to help refine the positioning of combining glyphs.
    353     FloatSize translation = glyphBuffer.offsetAt(from);
    354 
    355     CGContextSetFontSize(cgContext, platformData.size());
    356     wkSetCGContextFontRenderingStyle(cgContext, font->isSystemFont(), false, font->platformData().useGDI());
    357 
    358     FloatSize shadowOffset;
    359     float shadowBlur;
    360     Color shadowColor;
    361     ColorSpace shadowColorSpace;
    362     graphicsContext->getShadow(shadowOffset, shadowBlur, shadowColor, shadowColorSpace);
    363 
    364     bool hasSimpleShadow = graphicsContext->textDrawingMode() == TextModeFill && shadowColor.isValid() && !shadowBlur && (!graphicsContext->shadowsIgnoreTransforms() || graphicsContext->getCTM().isIdentityOrTranslationOrFlipped());
    365     if (hasSimpleShadow) {
    366         // Paint simple shadows ourselves instead of relying on CG shadows, to avoid losing subpixel antialiasing.
    367         graphicsContext->clearShadow();
    368         Color fillColor = graphicsContext->fillColor();
    369         Color shadowFillColor(shadowColor.red(), shadowColor.green(), shadowColor.blue(), shadowColor.alpha() * fillColor.alpha() / 255);
    370         graphicsContext->setFillColor(shadowFillColor, ColorSpaceDeviceRGB);
    371         float shadowTextX = point.x() + translation.width() + shadowOffset.width();
    372         // If shadows are ignoring transforms, then we haven't applied the Y coordinate flip yet, so down is negative.
    373         float shadowTextY = point.y() + translation.height() + shadowOffset.height() * (graphicsContext->shadowsIgnoreTransforms() ? -1 : 1);
    374         CGContextSetTextPosition(cgContext, shadowTextX, shadowTextY);
    375         CGContextShowGlyphsWithAdvances(cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
    376         if (font->syntheticBoldOffset()) {
    377             CGContextSetTextPosition(cgContext, point.x() + translation.width() + shadowOffset.width() + font->syntheticBoldOffset(), point.y() + translation.height() + shadowOffset.height());
    378             CGContextShowGlyphsWithAdvances(cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
    379         }
    380         graphicsContext->setFillColor(fillColor, ColorSpaceDeviceRGB);
    381     }
    382 
    383     CGContextSetTextPosition(cgContext, point.x() + translation.width(), point.y() + translation.height());
    384     CGContextShowGlyphsWithAdvances(cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
    385     if (font->syntheticBoldOffset()) {
    386         CGContextSetTextPosition(cgContext, point.x() + translation.width() + font->syntheticBoldOffset(), point.y() + translation.height());
    387         CGContextShowGlyphsWithAdvances(cgContext, glyphBuffer.glyphs(from), glyphBuffer.advances(from), numGlyphs);
    388     }
    389 
    390     if (hasSimpleShadow)
    391         graphicsContext->setShadow(shadowOffset, shadowBlur, shadowColor, ColorSpaceDeviceRGB);
    392 
    393     wkRestoreFontSmoothingStyle(cgContext, oldFontSmoothingStyle);
    394 }
    395 
    396 }
    397