From bff73e4c96fa4bf07534bd142302af08fa193bfa Mon Sep 17 00:00:00 2001 From: Lars Knoll Date: Wed, 21 Apr 2010 14:25:49 +0200 Subject: correctly position glyphs for complex languages Correctly use the positions calculated by getGlyphPositions to draw the glyphs. Simplify the logic a bit so that we don't need the glyphTransform anymore, but can instead just use the pathTransform for text drawing as well. Tested with latin, arabic, hebrew and Hindi text Task-number: QT-3300 Reviewed-by: Jason Barron --- src/openvg/qpaintengine_vg.cpp | 54 +++++++++++++++++------------------------- 1 file changed, 22 insertions(+), 32 deletions(-) diff --git a/src/openvg/qpaintengine_vg.cpp b/src/openvg/qpaintengine_vg.cpp index 7445fd7..cabb41c 100644 --- a/src/openvg/qpaintengine_vg.cpp +++ b/src/openvg/qpaintengine_vg.cpp @@ -183,7 +183,6 @@ public: qreal penScale; // Pen scaling factor from "transform". QTransform pathTransform; // Calculated VG path transformation. - QTransform glyphTransform; // Calculated VG glyph transformation. QTransform imageTransform; // Calculated VG image transformation. bool pathTransformSet; // True if path transform set in the VG context. @@ -508,24 +507,15 @@ void QVGPaintEnginePrivate::updateTransform(QPaintDevice *pdev) // | 1 0 0 | // | 0 -1 devh | // | 0 0 1 | - // The glyph transform uses a slightly different transformation: - // | 1 0 0 | | 1 0 0.5 | | 1 0 0.5 | - // | 0 -1 devh - 1 | * | 0 1 -0.5 | = | 0 -1 (devh - 0.5) | - // | 0 0 1 | | 0 0 1 | | 0 0 1 | // The full VG transform is effectively: // 1. Apply the user's transformation matrix. - // 2. Translate glyphs by an extra (0.5, -0.5). - // 3. Flip the co-ordinate system upside down. + // 2. Flip the co-ordinate system upside down. QTransform viewport(1.0f, 0.0f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, devh, 1.0f); - QTransform gviewport(1.0f, 0.0f, 0.0f, - 0.0f, -1.0f, 0.0f, - 0.5f, devh - 0.5f, 1.0f); // Compute the path transform and determine if it is projective. pathTransform = transform * viewport; - glyphTransform = transform * gviewport; bool projective = (pathTransform.m13() != 0.0f || pathTransform.m23() != 0.0f || pathTransform.m33() != 1.0f); @@ -534,7 +524,6 @@ void QVGPaintEnginePrivate::updateTransform(QPaintDevice *pdev) // so we will have to convert the co-ordinates ourselves. // Change the matrix to just the viewport transformation. pathTransform = viewport; - glyphTransform = gviewport; simpleTransform = false; } else { simpleTransform = true; @@ -3248,10 +3237,10 @@ void QVGFontGlyphCache::cacheGlyphs vgImageSubData(vgImage, qt_vg_imageBits(img), img.bytesPerLine(), VG_sARGB_8888_PRE, 0, 0, img.width(), img.height()); } } - origin[0] = -metrics.x.toReal() + 0.5f; - origin[1] = -metrics.y.toReal() + 0.5f; - escapement[0] = metrics.xoff.toReal(); - escapement[1] = metrics.yoff.toReal(); + origin[0] = -metrics.x.toReal(); + origin[1] = -metrics.y.toReal(); + escapement[0] = 0; + escapement[1] = 0; vgSetGlyphToImage(font, glyph, vgImage, origin, escapement); vgDestroyImage(vgImage); // Reduce reference count. #else @@ -3267,8 +3256,8 @@ void QVGFontGlyphCache::cacheGlyphs } origin[0] = 0; origin[1] = 0; - escapement[0] = metrics.xoff.toReal(); - escapement[1] = metrics.yoff.toReal(); + escapement[0] = 0; + escapement[1] = 0; vgSetGlyphToPath(font, glyph, vgPath, VG_FALSE, origin, escapement); vgDestroyPath(vgPath); // Reduce reference count. #endif // !defined(QVG_NO_IMAGE_GLYPHS) @@ -3293,10 +3282,8 @@ void QVGPaintEngine::drawTextItem(const QPointF &p, const QTextItem &textItem) // Get the glyphs and positions associated with the text item. QVarLengthArray positions; QVarLengthArray glyphs; - QTransform matrix = d->transform; - matrix.translate(p.x(), p.y()); - ti.fontEngine->getGlyphPositions - (ti.glyphs, matrix, ti.flags, glyphs, positions); + QTransform matrix; + ti.fontEngine->getGlyphPositions(ti.glyphs, matrix, ti.flags, glyphs, positions); // Find the glyph cache for this font. QVGFontCache::ConstIterator it = d->fontCache.constFind(ti.fontEngine); @@ -3320,7 +3307,7 @@ void QVGPaintEngine::drawTextItem(const QPointF &p, const QTextItem &textItem) } // Set the transformation to use for drawing the current glyphs. - QTransform glyphTransform(d->glyphTransform); + QTransform glyphTransform(d->pathTransform); glyphTransform.translate(p.x(), p.y()); #if defined(QVG_NO_IMAGE_GLYPHS) glyphTransform.scale(glyphCache->scaleX, glyphCache->scaleY); @@ -3330,10 +3317,18 @@ void QVGPaintEngine::drawTextItem(const QPointF &p, const QTextItem &textItem) // Add the glyphs from the text item into the glyph cache. glyphCache->cacheGlyphs(d, ti, glyphs); + // Create the array of adjustments between glyphs + QVarLengthArray adjustments_x(glyphs.size()); + QVarLengthArray adjustments_y(glyphs.size()); + for (int i = 1; i < glyphs.size(); ++i) { + adjustments_x[i-1] = (positions[i].x - positions[i-1].x).toReal(); + adjustments_y[i-1] = (positions[i].y - positions[i-1].y).toReal(); + } + // Set the glyph drawing origin. VGfloat origin[2]; - origin[0] = 0; - origin[1] = 0; + origin[0] = positions[0].x.toReal(); + origin[1] = positions[0].y.toReal(); vgSetfv(VG_GLYPH_ORIGIN, 2, origin); // Fast anti-aliasing for paths, better for images. @@ -3347,13 +3342,8 @@ void QVGPaintEngine::drawTextItem(const QPointF &p, const QTextItem &textItem) // Draw the glyphs. We need to fill with the brush associated with // the Qt pen, not the Qt brush. d->ensureBrush(state()->pen.brush()); - if (ti.renderFlags() & QTextItem::RightToLeft) { - for (int index = glyphs.size() - 1; index >= 0; --index) - vgDrawGlyph(glyphCache->font, glyphs[index], VG_FILL_PATH, VG_TRUE); - } else { - vgDrawGlyphs(glyphCache->font, glyphs.size(), (VGuint*)glyphs.data(), - NULL, NULL, VG_FILL_PATH, VG_TRUE); - } + vgDrawGlyphs(glyphCache->font, glyphs.size(), (VGuint*)glyphs.data(), + adjustments_x.data(), adjustments_y.data(), VG_FILL_PATH, VG_TRUE); #else // OpenGL 1.0 does not have support for VGFont and glyphs, // so fall back to the default Qt path stroking algorithm. -- cgit v0.12