int QTextureGlyphCache::calculateSubPixelPositionCount(glyph_t glyph) const
{
    // Test 12 different subpixel positions since it factors into 3*4 so it gives
    // the coverage we need.

    QList<QImage> images;
    for (int i=0; i<12; ++i) {
        QImage img = textureMapForGlyph(glyph, QFixed::fromReal(i / 12.0));

        if (images.isEmpty()) {
            QPainterPath path;
            QFixedPoint point;
            m_current_fontengine->addGlyphsToPath(&glyph, &point, 1, &path, QTextItem::RenderFlags());

            // Glyph is space, return 0 to indicate that we need to keep trying
            if (path.isEmpty())
                break;

            images.append(img);
        } else {
            bool found = false;
            for (int j=0; j<images.size(); ++j) {
                if (images.at(j) == img) {
                    found = true;
                    break;
                }
            }
            if (!found)
                images.append(img);
        }
    }

    return images.size();
}
void QGLTextureGlyphCache::fillTexture(const Coord &c, glyph_t glyph)
{
    QImage mask = textureMapForGlyph(glyph);
    const int maskWidth = mask.width();
    const int maskHeight = mask.height();

    if (mask.format() == QImage::Format_Mono) {
        mask = mask.convertToFormat(QImage::Format_Indexed8);
        for (int y = 0; y < maskHeight; ++y) {
            uchar *src = (uchar *) mask.scanLine(y);
            for (int x = 0; x < maskWidth; ++x)
                src[x] = -src[x]; // convert 0 and 1 into 0 and 255
        }
    } else if (mask.format() == QImage::Format_RGB32) {
        // Make the alpha component equal to the average of the RGB values.
        // This is needed when drawing sub-pixel antialiased text on translucent targets.
        for (int y = 0; y < maskHeight; ++y) {
            quint32 *src = (quint32 *) mask.scanLine(y);
            for (int x = 0; x < maskWidth; ++x) {
                uchar r = src[x] >> 16;
                uchar g = src[x] >> 8;
                uchar b = src[x];
                quint32 avg = (quint32(r) + quint32(g) + quint32(b) + 1) / 3; // "+1" for rounding.
                src[x] = (src[x] & 0x00ffffff) | (avg << 24);
            }
        }
    }

    glBindTexture(GL_TEXTURE_2D, m_texture);
    if (mask.format() == QImage::Format_RGB32) {
        glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, GL_BGRA, GL_UNSIGNED_BYTE, mask.bits());
    } else {
#ifdef QT_OPENGL_ES2
        glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, GL_ALPHA, GL_UNSIGNED_BYTE, mask.bits());
#else
        // glTexSubImage2D() might cause some garbage to appear in the texture if the mask width is
        // not a multiple of four bytes. The bug appeared on a computer with 32-bit Windows Vista
        // and nVidia GeForce 8500GT. GL_UNPACK_ALIGNMENT is set to four bytes, 'mask' has a
        // multiple of four bytes per line, and most of the glyph shows up correctly in the
        // texture, which makes me think that this is a driver bug.
        // One workaround is to make sure the mask width is a multiple of four bytes, for instance
        // by converting it to a format with four bytes per pixel. Another is to copy one line at a
        // time.

        for (int i = 0; i < maskHeight; ++i)
            glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y + i, maskWidth, 1, GL_ALPHA, GL_UNSIGNED_BYTE, mask.scanLine(i));
#endif
    }
}
示例#3
0
void QGLTextureGlyphCache::fillTexture(const Coord &c, glyph_t glyph, QFixed subPixelPosition)
{
    if (ctx == 0) {
        qWarning("QGLTextureGlyphCache::fillTexture: Called with no context");
        return;
    }

    QGLGlyphTexture *glyphTexture = m_textureResource.value(ctx);
    if (ctx->d_ptr->workaround_brokenFBOReadBack) {
        QImageTextureGlyphCache::fillTexture(c, glyph, subPixelPosition);

        glBindTexture(GL_TEXTURE_2D, glyphTexture->m_texture);
        const QImage &texture = image();
        const uchar *bits = texture.constBits();
        bits += c.y * texture.bytesPerLine() + c.x;
        for (int i=0; i<c.h; ++i) {
            glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y + i, c.w, 1, GL_ALPHA, GL_UNSIGNED_BYTE, bits);
            bits += texture.bytesPerLine();
        }
        return;
    }

    QImage mask = textureMapForGlyph(glyph, subPixelPosition);
    const int maskWidth = mask.width();
    const int maskHeight = mask.height();

    if (mask.format() == QImage::Format_Mono) {
        mask = mask.convertToFormat(QImage::Format_Indexed8);
        for (int y = 0; y < maskHeight; ++y) {
            uchar *src = (uchar *) mask.scanLine(y);
            for (int x = 0; x < maskWidth; ++x)
                src[x] = -src[x]; // convert 0 and 1 into 0 and 255
        }
    } else if (mask.format() == QImage::Format_RGB32) {
        // Make the alpha component equal to the average of the RGB values.
        // This is needed when drawing sub-pixel antialiased text on translucent targets.
        for (int y = 0; y < maskHeight; ++y) {
            quint32 *src = (quint32 *) mask.scanLine(y);
            for (int x = 0; x < maskWidth; ++x) {
                uchar r = src[x] >> 16;
                uchar g = src[x] >> 8;
                uchar b = src[x];
                quint32 avg = (quint32(r) + quint32(g) + quint32(b) + 1) / 3; // "+1" for rounding.
                src[x] = (src[x] & 0x00ffffff) | (avg << 24);
            }
        }
    }

    glBindTexture(GL_TEXTURE_2D, glyphTexture->m_texture);
    if (mask.format() == QImage::Format_RGB32) {
        glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, GL_BGRA, GL_UNSIGNED_BYTE, mask.bits());
    } else {
        // glTexSubImage2D() might cause some garbage to appear in the texture if the mask width is
        // not a multiple of four bytes. The bug appeared on a computer with 32-bit Windows Vista
        // and nVidia GeForce 8500GT. GL_UNPACK_ALIGNMENT is set to four bytes, 'mask' has a
        // multiple of four bytes per line, and most of the glyph shows up correctly in the
        // texture, which makes me think that this is a driver bug.
        // One workaround is to make sure the mask width is a multiple of four bytes, for instance
        // by converting it to a format with four bytes per pixel. Another is to copy one line at a
        // time.

        if (!ctx->d_ptr->workaround_brokenAlphaTexSubImage_init) {
            // don't know which driver versions exhibit this bug, so be conservative for now
            const QByteArray versionString(reinterpret_cast<const char*>(glGetString(GL_VERSION)));
            ctx->d_ptr->workaround_brokenAlphaTexSubImage = versionString.indexOf("NVIDIA") >= 0;
            ctx->d_ptr->workaround_brokenAlphaTexSubImage_init = true;
        }
#ifndef QT_WEBOS
        if (ctx->d_ptr->workaround_brokenAlphaTexSubImage) {
            for (int i = 0; i < maskHeight; ++i)
                glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y + i, maskWidth, 1, GL_ALPHA, GL_UNSIGNED_BYTE, mask.scanLine(i));
        } else {
            glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y, maskWidth, maskHeight, GL_ALPHA, GL_UNSIGNED_BYTE, mask.bits());
        }
#else // QT_WEBOS
        for (int i = 0; i < maskHeight; ++i)
                glTexSubImage2D(GL_TEXTURE_2D, 0, c.x, c.y + i, maskWidth, 1, GL_ALPHA, GL_UNSIGNED_BYTE, mask.scanLine(i));
#endif
    }
}
void QImageTextureGlyphCache::fillTexture(const Coord &c, glyph_t g, QFixed subPixelPosition)
{
    QImage mask = textureMapForGlyph(g, subPixelPosition);

#ifdef CACHE_DEBUG
    printf("fillTexture of %dx%d at %d,%d in the cache of %dx%d\n", c.w, c.h, c.x, c.y, m_image.width(), m_image.height());
    if (mask.width() > c.w || mask.height() > c.h) {
        printf("   ERROR; mask is bigger than reserved space! %dx%d instead of %dx%d\n", mask.width(), mask.height(), c.w,c.h);
        return;
    }
#endif

    if (m_type == QFontEngineGlyphCache::Raster_RGBMask) {        
        QImage ref(m_image.bits() + (c.x * 4 + c.y * m_image.bytesPerLine()),
                   qMax(mask.width(), c.w), qMax(mask.height(), c.h), m_image.bytesPerLine(),
                   m_image.format());
        QPainter p(&ref);
        p.setCompositionMode(QPainter::CompositionMode_Source);
        p.fillRect(0, 0, c.w, c.h, QColor(0,0,0,0)); // TODO optimize this
        p.drawImage(0, 0, mask);
        p.end();
    } else if (m_type == QFontEngineGlyphCache::Raster_Mono) {
        if (mask.depth() > 1) {
            // TODO optimize this
            mask = mask.alphaChannel();
            mask.invertPixels();
            mask = mask.convertToFormat(QImage::Format_Mono);
        }

        int mw = qMin(mask.width(), c.w);
        int mh = qMin(mask.height(), c.h);
        uchar *d = m_image.bits();
        int dbpl = m_image.bytesPerLine();

        for (int y = 0; y < c.h; ++y) {
            uchar *dest = d + (c.y + y) *dbpl + c.x/8;

            if (y < mh) {
                uchar *src = mask.scanLine(y);
                for (int x = 0; x < c.w/8; ++x) {
                    if (x < (mw+7)/8)
                        dest[x] = src[x];
                    else
                        dest[x] = 0;
                }
            } else {
                for (int x = 0; x < c.w/8; ++x)
                    dest[x] = 0;
            }
        }
    } else { // A8
        int mw = qMin(mask.width(), c.w);
        int mh = qMin(mask.height(), c.h);
        uchar *d = m_image.bits();
        int dbpl = m_image.bytesPerLine();

        if (mask.depth() == 1) {
            for (int y = 0; y < c.h; ++y) {
                uchar *dest = d + (c.y + y) *dbpl + c.x;
                if (y < mh) {
                    uchar *src = (uchar *) mask.scanLine(y);
                    for (int x = 0; x < c.w; ++x) {
                        if (x < mw)
                            dest[x] = (src[x >> 3] & (1 << (7 - (x & 7)))) > 0 ? 255 : 0;
                    }
                }
            }
        } else if (mask.depth() == 8) {