gecko-dev/gfx/thebes/gfxFontMissingGlyphs.cpp

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C++

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Corporation code.
*
* The Initial Developer of the Original Code is Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2007
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Robert O'Callahan <robert@ocallahan.org>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "gfxFontMissingGlyphs.h"
#define CHAR_BITS(b00, b01, b02, b10, b11, b12, b20, b21, b22, b30, b31, b32, b40, b41, b42) \
((b00 << 0) | (b01 << 1) | (b02 << 2) | (b10 << 3) | (b11 << 4) | (b12 << 5) | \
(b20 << 6) | (b21 << 7) | (b22 << 8) | (b30 << 9) | (b31 << 10) | (b32 << 11) | \
(b40 << 12) | (b41 << 13) | (b42 << 14))
static const PRUint16 glyphMicroFont[16] = {
CHAR_BITS(0, 1, 0,
1, 0, 1,
1, 0, 1,
1, 0, 1,
0, 1, 0),
CHAR_BITS(0, 1, 0,
0, 1, 0,
0, 1, 0,
0, 1, 0,
0, 1, 0),
CHAR_BITS(1, 1, 1,
0, 0, 1,
1, 1, 1,
1, 0, 0,
1, 1, 1),
CHAR_BITS(1, 1, 1,
0, 0, 1,
1, 1, 1,
0, 0, 1,
1, 1, 1),
CHAR_BITS(1, 0, 1,
1, 0, 1,
1, 1, 1,
0, 0, 1,
0, 0, 1),
CHAR_BITS(1, 1, 1,
1, 0, 0,
1, 1, 1,
0, 0, 1,
1, 1, 1),
CHAR_BITS(1, 1, 1,
1, 0, 0,
1, 1, 1,
1, 0, 1,
1, 1, 1),
CHAR_BITS(1, 1, 1,
0, 0, 1,
0, 0, 1,
0, 0, 1,
0, 0, 1),
CHAR_BITS(0, 1, 0,
1, 0, 1,
0, 1, 0,
1, 0, 1,
0, 1, 0),
CHAR_BITS(1, 1, 1,
1, 0, 1,
1, 1, 1,
0, 0, 1,
0, 0, 1),
CHAR_BITS(1, 1, 1,
1, 0, 1,
1, 1, 1,
1, 0, 1,
1, 0, 1),
CHAR_BITS(1, 1, 0,
1, 0, 1,
1, 1, 0,
1, 0, 1,
1, 1, 0),
CHAR_BITS(0, 1, 1,
1, 0, 0,
1, 0, 0,
1, 0, 0,
0, 1, 1),
CHAR_BITS(1, 1, 0,
1, 0, 1,
1, 0, 1,
1, 0, 1,
1, 1, 0),
CHAR_BITS(1, 1, 1,
1, 0, 0,
1, 1, 1,
1, 0, 0,
1, 1, 1),
CHAR_BITS(1, 1, 1,
1, 0, 0,
1, 1, 1,
1, 0, 0,
1, 0, 0)
};
/* Parameters that control the rendering of hexboxes. They look like this:
BMP codepoints non-BMP codepoints
(U+0000 - U+FFFF) (U+10000 - U+10FFFF)
+---------+ +-------------+
| | | |
| HHH HHH | | HHH HHH HHH |
| HHH HHH | | HHH HHH HHH |
| HHH HHH | | HHH HHH HHH |
| HHH HHH | | HHH HHH HHH |
| HHH HHH | | HHH HHH HHH |
| | | |
| HHH HHH | | HHH HHH HHH |
| HHH HHH | | HHH HHH HHH |
| HHH HHH | | HHH HHH HHH |
| HHH HHH | | HHH HHH HHH |
| HHH HHH | | HHH HHH HHH |
| | | |
+---------+ +-------------+
*/
/** Width of a minifont glyph (see above) */
static const int MINIFONT_WIDTH = 3;
/** Height of a minifont glyph (see above) */
static const int MINIFONT_HEIGHT = 5;
/**
* Gap between minifont glyphs (both horizontal and vertical) and also
* the minimum desired gap between the box border and the glyphs
*/
static const int HEX_CHAR_GAP = 1;
/**
* The amount of space between the vertical edge of the glyphbox and the
* box border. We make this nonzero so that when multiple missing glyphs
* occur consecutively there's a gap between their rendered boxes.
*/
static const int BOX_HORIZONTAL_INSET = 1;
/** The width of the border */
static const int BOX_BORDER_WIDTH = 1;
/**
* The scaling factor for the border opacity; this is multiplied by the current
* opacity being used to draw the text.
*/
static const gfxFloat BOX_BORDER_OPACITY = 0.5;
/**
* Draw a single hex character using the current color. A nice way to do this
* would be to fill in an A8 image surface and then use it as a mask
* to paint the current color. Tragically this doesn't currently work with the
* Quartz cairo backend which doesn't generally support masking with surfaces.
* So for now we just paint a bunch of rectangles...
*/
static void
DrawHexChar(gfxContext *aContext, const gfxPoint& aPt, PRUint32 aDigit)
{
aContext->NewPath();
PRUint32 glyphBits = glyphMicroFont[aDigit];
int x, y;
for (y = 0; y < MINIFONT_HEIGHT; ++y) {
for (x = 0; x < MINIFONT_WIDTH; ++x) {
if (glyphBits & 1) {
aContext->Rectangle(gfxRect(x, y, 1, 1) + aPt, PR_TRUE);
}
glyphBits >>= 1;
}
}
aContext->Fill();
}
void
gfxFontMissingGlyphs::DrawMissingGlyph(gfxContext *aContext, const gfxRect& aRect,
PRUint32 aChar)
{
aContext->Save();
gfxRGBA currentColor;
if (!aContext->GetDeviceColor(currentColor)) {
// We're currently drawing with some kind of pattern... Just draw
// the missing-glyph data in black.
currentColor = gfxRGBA(0,0,0,1);
}
// Stroke a rectangle so that the stroke's left edge is inset one pixel
// from the left edge of the glyph box and the stroke's right edge
// is inset one pixel from the right edge of the glyph box.
gfxFloat halfBorderWidth = BOX_BORDER_WIDTH/2.0;
gfxFloat borderLeft = aRect.X() + BOX_HORIZONTAL_INSET + halfBorderWidth;
gfxFloat borderRight = aRect.XMost() - BOX_HORIZONTAL_INSET - halfBorderWidth;
gfxRect borderStrokeRect(borderLeft, aRect.Y() + halfBorderWidth,
borderRight - borderLeft, aRect.Height() - 2*halfBorderWidth);
if (!borderStrokeRect.IsEmpty()) {
aContext->SetLineWidth(BOX_BORDER_WIDTH);
aContext->SetDash(gfxContext::gfxLineSolid);
aContext->SetLineCap(gfxContext::LINE_CAP_SQUARE);
aContext->SetLineJoin(gfxContext::LINE_JOIN_MITER);
gfxRGBA color = currentColor;
color.a *= BOX_BORDER_OPACITY;
aContext->SetDeviceColor(color);
aContext->NewPath();
aContext->Rectangle(borderStrokeRect);
#ifdef MOZ_GFX_OPTIMIZE_MOBILE
aContext->Fill();
#else
aContext->Stroke();
#endif
}
#ifndef MOZ_GFX_OPTIMIZE_MOBILE
gfxPoint center(aRect.X() + aRect.Width()/2,
aRect.Y() + aRect.Height()/2);
gfxFloat halfGap = HEX_CHAR_GAP/2.0;
gfxFloat top = -(MINIFONT_HEIGHT + halfGap);
if (aChar < 0x10000) {
if (aRect.Width() >= 2*MINIFONT_WIDTH + HEX_CHAR_GAP &&
aRect.Height() >= 2*MINIFONT_HEIGHT + HEX_CHAR_GAP) {
// Draw 4 digits for BMP
aContext->SetDeviceColor(currentColor);
gfxFloat left = -(MINIFONT_WIDTH + halfGap);
DrawHexChar(aContext,
center + gfxPoint(left, top), (aChar >> 12) & 0xF);
DrawHexChar(aContext,
center + gfxPoint(halfGap, top), (aChar >> 8) & 0xF);
DrawHexChar(aContext,
center + gfxPoint(left, halfGap), (aChar >> 4) & 0xF);
DrawHexChar(aContext,
center + gfxPoint(halfGap, halfGap), aChar & 0xF);
}
} else {
if (aRect.Width() >= 3*MINIFONT_WIDTH + 2*HEX_CHAR_GAP &&
aRect.Height() >= 2*MINIFONT_HEIGHT + HEX_CHAR_GAP) {
// Draw 6 digits for non-BMP
aContext->SetDeviceColor(currentColor);
gfxFloat first = -(MINIFONT_WIDTH * 1.5 + HEX_CHAR_GAP);
gfxFloat second = -(MINIFONT_WIDTH / 2.0);
gfxFloat third = (MINIFONT_WIDTH / 2.0 + HEX_CHAR_GAP);
DrawHexChar(aContext,
center + gfxPoint(first, top), (aChar >> 20) & 0xF);
DrawHexChar(aContext,
center + gfxPoint(second, top), (aChar >> 16) & 0xF);
DrawHexChar(aContext,
center + gfxPoint(third, top), (aChar >> 12) & 0xF);
DrawHexChar(aContext,
center + gfxPoint(first, halfGap), (aChar >> 8) & 0xF);
DrawHexChar(aContext,
center + gfxPoint(second, halfGap), (aChar >> 4) & 0xF);
DrawHexChar(aContext,
center + gfxPoint(third, halfGap), aChar & 0xF);
}
}
#endif
aContext->Restore();
}
gfxFloat
gfxFontMissingGlyphs::GetDesiredMinWidth(PRUint32 aChar)
{
/**
* The minimum desired width for a missing-glyph glyph box. I've laid it out
* like this so you can see what goes where.
*/
return BOX_HORIZONTAL_INSET + BOX_BORDER_WIDTH + HEX_CHAR_GAP +
MINIFONT_WIDTH + HEX_CHAR_GAP + MINIFONT_WIDTH +
((aChar < 0x10000) ? 0 : HEX_CHAR_GAP + MINIFONT_WIDTH) +
HEX_CHAR_GAP + BOX_BORDER_WIDTH + BOX_HORIZONTAL_INSET;
}