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freemheg: Correct font x-resolution
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The x-resolution used for size calculations of blocks of text is incorrect.
This most noticeably causes tables to be incorrectl;y formatted.

This patch also corrects a bug in the text block size calculation.

Signed-off-by: Lawrence Rust <lvr@softsystem.co.uk>
Signed-off-by: Stuart Morgan <smorgan@mythtv.org>
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@stuartm
Lawrence Rust authored and stuartm committed Jul 6, 2012
1 parent 8072c0e commit 462c6eb
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Showing 2 changed files with 50 additions and 23 deletions.
6 changes: 4 additions & 2 deletions mythtv/libs/libmythfreemheg/Text.cpp
View file
Expand Up @@ -520,8 +520,10 @@ MHTextLine::~MHTextLine()
}
}

// Tabs are set every 56 points (45 pixels).
#define TABSTOP 45
// Tabs are set every 56 pixels
// = (FONT_WIDTHRES * 56)/ 72 points - see libmythtv/mhi.cpp
// = (54 * 56)/72 = 42
#define TABSTOP 42 // pts
static inline int Tabs(int nXpos, int nTabCount)
{
int nNextTab = nXpos;
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67 changes: 46 additions & 21 deletions mythtv/libs/libmythtv/mhi.cpp
View file
Expand Up @@ -17,9 +17,10 @@
static bool ft_loaded = false;
static FT_Library ft_library;

#define FONT_WIDTHRES 48
#define FONT_HEIGHTRES 72
#define FONT_TO_USE "FreeSans.ttf"
#define FONT_WIDTHRES 54
#define FONT_HEIGHTRES 72 // 1 pixel per point
#define FONT_TO_USE "FreeSans.ttf" // Tiresias Screenfont.ttf is mandated


#define SCALED_X(arg1) (int)(((float)arg1 * m_xScale) + 0.5f)
#define SCALED_Y(arg1) (int)(((float)arg1 * m_yScale) + 0.5f)
Expand Down Expand Up @@ -107,7 +108,7 @@ bool MHIContext::LoadFont(QString name)
if (!errorD)
return true;

LOG(VB_GENERAL, LOG_ERR, QString("Unable to find font: %1").arg(name));
LOG(VB_GENERAL, LOG_ERR, QString("[mhi] Unable to find font: %1").arg(name));
return false;
}

Expand Down Expand Up @@ -947,6 +948,18 @@ void MHIText::SetFont(int size, bool isBold, bool isItalic)
// Bold and Italic are currently ignored.
}

// FT sizes are in 26.6 fixed point form
const int kShift = 6;
static inline FT_F26Dot6 Point2FT(int pt)
{
return pt << kShift;
}

static inline int FT2Point(FT_F26Dot6 fp)
{
return (fp + (1<<(kShift-1))) >> kShift;
}

// Return the bounding rectangle for a piece of text drawn in the
// current font. If maxSize is non-negative it sets strLen to the
// number of characters that will fit in the space and returns the
Expand All @@ -960,24 +973,31 @@ QRect MHIText::GetBounds(const QString &str, int &strLen, int maxSize)
return QRect(0,0,0,0);

FT_Face face = m_parent->GetFontFace();
FT_Error error = FT_Set_Char_Size(face, 0, m_fontsize*64,
FT_Error error = FT_Set_Char_Size(face, 0, Point2FT(m_fontsize),
FONT_WIDTHRES, FONT_HEIGHTRES);
if (error)
return QRect(0,0,0,0);

FT_GlyphSlot slot = face->glyph; /* a small shortcut */

int maxAscent = 0, maxDescent = 0, width = 0;
FT_Bool useKerning = FT_HAS_KERNING(face);
FT_UInt previous = 0;

for (int n = 0; n < strLen; n++)
{
QChar ch = str[n];
QChar ch = str.at(n);
FT_UInt glyphIndex = FT_Get_Char_Index(face, ch.unicode());

if (glyphIndex == 0)
{
LOG(VB_MHEG, LOG_INFO, QString("[mhi] Unknown glyph 0x%1")
.arg(ch.unicode(),0,16));
previous = 0;
continue;
}

int kerning = 0;

if (useKerning && previous != 0 && glyphIndex != 0)
if (useKerning && previous != 0)
{
FT_Vector delta;
FT_Get_Kerning(face, previous, glyphIndex,
Expand All @@ -990,9 +1010,12 @@ QRect MHIText::GetBounds(const QString &str, int &strLen, int maxSize)
if (error)
continue; // ignore errors.

FT_GlyphSlot slot = face->glyph; /* a small shortcut */
FT_Pos advance = slot->metrics.horiAdvance + kerning;

if (maxSize >= 0)
{
if ((width + slot->advance.x + kerning + (1<<6)-1) >> 6 > maxSize)
if (FT2Point(width + advance) > maxSize)
{
// There isn't enough space for this character.
strLen = n;
Expand All @@ -1008,15 +1031,11 @@ QRect MHIText::GetBounds(const QString &str, int &strLen, int maxSize)
if (descent > maxDescent)
maxDescent = descent;

width += slot->advance.x + kerning;
width += advance;
previous = glyphIndex;
}

maxAscent = (maxAscent + (1<<6)-1) >> 6;
maxDescent = (maxDescent + (1<<6)-1) >> 6;

return QRect(0, -maxAscent,
(width+(1<<6)-1) >> 6, maxAscent + maxDescent);
return QRect(0, -FT2Point(maxAscent), FT2Point(width), FT2Point(maxAscent + maxDescent));
}

// Reset the image and fill it with transparent ink.
Expand All @@ -1043,13 +1062,12 @@ void MHIText::AddText(int x, int y, const QString &str, MHRgba colour)
{
if (!m_parent->IsFaceLoaded()) return;
FT_Face face = m_parent->GetFontFace();
FT_GlyphSlot slot = face->glyph;
FT_Error error = FT_Set_Char_Size(face, 0, m_fontsize*64,
FT_Error error = FT_Set_Char_Size(face, 0, Point2FT(m_fontsize),
FONT_WIDTHRES, FONT_HEIGHTRES);

// X positions are computed to 64ths and rounded.
// Y positions are in pixels
int posX = x << 6;
int posX = Point2FT(x);
int pixelY = y;
FT_Bool useKerning = FT_HAS_KERNING(face);
FT_UInt previous = 0;
Expand All @@ -1060,7 +1078,13 @@ void MHIText::AddText(int x, int y, const QString &str, MHRgba colour)
// Load the glyph.
QChar ch = str[n];
FT_UInt glyphIndex = FT_Get_Char_Index(face, ch.unicode());
if (useKerning && previous != 0 && glyphIndex != 0)
if (glyphIndex == 0)
{
previous = 0;
continue;
}

if (useKerning && previous != 0)
{
FT_Vector delta;
FT_Get_Kerning(face, previous, glyphIndex,
Expand All @@ -1072,6 +1096,7 @@ void MHIText::AddText(int x, int y, const QString &str, MHRgba colour)
if (error)
continue; // ignore errors

FT_GlyphSlot slot = face->glyph;
if (slot->format != FT_GLYPH_FORMAT_BITMAP)
continue; // Problem

Expand All @@ -1080,7 +1105,7 @@ void MHIText::AddText(int x, int y, const QString &str, MHRgba colour)

unsigned char *source = slot->bitmap.buffer;
// Get the origin for the bitmap
int baseX = ((posX + (1 << 5)) >> 6) + slot->bitmap_left;
int baseX = FT2Point(posX) + slot->bitmap_left;
int baseY = pixelY - slot->bitmap_top;
// Copy the bitmap into the image.
for (int i = 0; i < slot->bitmap.rows; i++)
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