/*
 * Copyright (c) 2008, Google Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "core/platform/graphics/skia/SkiaFontWin.h"

#include "core/platform/graphics/Gradient.h"
#include "core/platform/graphics/GraphicsContext.h"
#include "core/platform/graphics/Pattern.h"
#include "core/platform/graphics/SimpleFontData.h"
#include "core/platform/graphics/chromium/FontPlatformDataChromiumWin.h"
#include "platform/transforms/AffineTransform.h"
#include "third_party/skia/include/core/SkCanvas.h"
#include "third_party/skia/include/core/SkDevice.h"
#include "third_party/skia/include/core/SkPaint.h"
#include "third_party/skia/include/core/SkShader.h"
#include "third_party/skia/include/core/SkTemplates.h"
#include "wtf/RefPtr.h"

namespace WebCore {

static void skiaDrawText(GraphicsContext* context,
                         const SkPoint& point,
                         const SkRect& textRect,
                         SkPaint* paint,
                         const WORD* glyphs,
                         const int* advances,
                         const GOFFSET* offsets,
                         int numGlyphs)
{
    // Reserve space for 64 SkPoints on the stack. If numGlyphs is larger, the array
    // will dynamically allocate it space for numGlyph glyphs. This is used to store
    // the computed x,y locations. In the case where offsets==null, then we use it
    // to store (twice as many) SkScalars for x[]
    static const size_t kLocalGlyphMax = 64;

    SkScalar x = point.fX;
    SkScalar y = point.fY;
    if (offsets) {
        SkAutoSTArray<kLocalGlyphMax, SkPoint> storage(numGlyphs);
        SkPoint* pos = storage.get();
        for (int i = 0; i < numGlyphs; i++) {
            // GDI has dv go up, so we negate it
            pos[i].set(x + SkIntToScalar(offsets[i].du),
                       y + -SkIntToScalar(offsets[i].dv));
            x += SkIntToScalar(advances[i]);
        }
        context->drawPosText(glyphs, numGlyphs * sizeof(uint16_t), pos, textRect, *paint);
    } else {
        SkAutoSTArray<kLocalGlyphMax * 2, SkScalar> storage(numGlyphs);
        SkScalar* xpos = storage.get();
        for (int i = 0; i < numGlyphs; i++) {
            xpos[i] = x;
            x += SkIntToScalar(advances[i]);
        }
        context->drawPosTextH(glyphs, numGlyphs * sizeof(uint16_t),
                             xpos, y, textRect, *paint);
    }
}

static void paintSkiaText(GraphicsContext* context,
    const FontPlatformData& data,
    SkTypeface* face, float size, uint32_t textFlags,
    int numGlyphs,
    const WORD* glyphs,
    const int* advances,
    const GOFFSET* offsets,
    const SkPoint& origin,
    const SkRect& textRect)
{
    TextDrawingModeFlags textMode = context->textDrawingMode();

    // Filling (if necessary). This is the common case.
    SkPaint paint;
    context->setupPaintForFilling(&paint);
    paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
    data.setupPaint(&paint, context);

    // FIXME: Only needed to support the HFONT based paintSkiaText
    // version where a new typeface is created from the HFONT.
    // As such it can go away once the HFONT code path is removed.
    paint.setTypeface(face);

    bool didFill = false;

    if ((textMode & TextModeFill) && (SkColorGetA(paint.getColor()) || paint.getLooper())) {
        skiaDrawText(context, origin, textRect, &paint, &glyphs[0], &advances[0], &offsets[0], numGlyphs);
        didFill = true;
    }

    // Stroking on top (if necessary).
    if ((textMode & TextModeStroke)
        && context->strokeStyle() != NoStroke
        && context->strokeThickness() > 0) {

        paint.reset();
        context->setupPaintForStroking(&paint);
        paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
        data.setupPaint(&paint, context);
        paint.setTypeface(face);

        if (didFill) {
            // If there is a shadow and we filled above, there will already be
            // a shadow. We don't want to draw it again or it will be too dark
            // and it will go on top of the fill.
            //
            // Note that this isn't strictly correct, since the stroke could be
            // very thick and the shadow wouldn't account for this. The "right"
            // thing would be to draw to a new layer and then draw that layer
            // with a shadow. But this is a lot of extra work for something
            // that isn't normally an issue.
            paint.setLooper(0);
        }

        skiaDrawText(context, origin, textRect, &paint, &glyphs[0], &advances[0], &offsets[0], numGlyphs);
    }
}

///////////////////////////////////////////////////////////////////////////////////////////

void paintSkiaText(GraphicsContext* context,
                   const FontPlatformData& data,
                   int numGlyphs,
                   const WORD* glyphs,
                   const int* advances,
                   const GOFFSET* offsets,
                   const SkPoint& origin,
                   const SkRect& textRect)
{
    paintSkiaText(context, data, data.typeface(), data.size(), data.paintTextFlags(),
                  numGlyphs, glyphs, advances, offsets, origin, textRect);
}

void paintSkiaText(GraphicsContext* context,
    const FontPlatformData& data,
    HFONT hfont,
    int numGlyphs,
    const WORD* glyphs,
    const int* advances,
    const GOFFSET* offsets,
    const SkPoint& origin,
    const SkRect& textRect)
{
    int size;
    int paintTextFlags;

    // Ensure font load for printing, because PDF device needs it.
    if (context->isPrintingDevice())
        FontPlatformData::ensureFontLoaded(hfont);

    RefPtr<SkTypeface> face = CreateTypefaceFromHFont(hfont, &size, &paintTextFlags);
    paintSkiaText(context, data, face.get(), size, paintTextFlags, numGlyphs, glyphs, advances, offsets, origin, textRect);
}

}  // namespace WebCore