protot/3rdparty/bgfx/examples/common/font/text_metrics.cpp

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2016-08-29 22:31:11 +02:00
/*
* Copyright 2013 Jeremie Roy. All rights reserved.
* License: https://github.com/bkaradzic/bgfx#license-bsd-2-clause
*/
#include <wchar.h> // wcslen
#include "text_metrics.h"
#include "utf8.h"
TextMetrics::TextMetrics(FontManager* _fontManager)
: m_fontManager(_fontManager)
, m_width(0)
, m_height(0)
, m_x(0)
, m_lineHeight(0)
, m_lineGap(0)
{
}
void TextMetrics::appendText(FontHandle _fontHandle, const char* _string)
{
const FontInfo& font = m_fontManager->getFontInfo(_fontHandle);
if (font.lineGap > m_lineGap)
{
m_lineGap = font.lineGap;
}
if ( (font.ascender - font.descender) > m_lineHeight)
{
m_height -= m_lineHeight;
m_lineHeight = font.ascender - font.descender;
m_height += m_lineHeight;
}
CodePoint codepoint = 0;
uint32_t state = 0;
for (; *_string; ++_string)
{
if (!utf8_decode(&state, (uint32_t*)&codepoint, *_string) )
{
const GlyphInfo* glyph = m_fontManager->getGlyphInfo(_fontHandle, codepoint);
if (NULL != glyph)
{
if (codepoint == L'\n')
{
m_height += m_lineGap + font.ascender - font.descender;
m_lineGap = font.lineGap;
m_lineHeight = font.ascender - font.descender;
m_x = 0;
break;
}
m_x += glyph->advance_x;
if(m_x > m_width)
{
m_width = m_x;
}
}
else
{
BX_CHECK(false, "Glyph not found");
}
}
}
BX_CHECK(state == UTF8_ACCEPT, "The string is not well-formed");
}
void TextMetrics::appendText(FontHandle _fontHandle, const wchar_t* _string)
{
const FontInfo& font = m_fontManager->getFontInfo(_fontHandle);
if (font.lineGap > m_lineGap)
{
m_lineGap = font.lineGap;
}
if ( (font.ascender - font.descender) > m_lineHeight)
{
m_height -= m_lineHeight;
m_lineHeight = font.ascender - font.descender;
m_height += m_lineHeight;
}
for (uint32_t ii = 0, end = (uint32_t)wcslen(_string); ii < end; ++ii)
{
uint32_t codepoint = _string[ii];
const GlyphInfo* glyph = m_fontManager->getGlyphInfo(_fontHandle, codepoint);
if (NULL != glyph)
{
if (codepoint == L'\n')
{
m_height += m_lineGap + font.ascender - font.descender;
m_lineGap = font.lineGap;
m_lineHeight = font.ascender - font.descender;
m_x = 0;
break;
}
m_x += glyph->advance_x;
if(m_x > m_width)
{
m_width = m_x;
}
}
else
{
BX_CHECK(false, "Glyph not found");
}
}
}
TextLineMetrics::TextLineMetrics(const FontInfo& _fontInfo)
{
m_lineHeight = _fontInfo.ascender - _fontInfo.descender + _fontInfo.lineGap;
}
uint32_t TextLineMetrics::getLineCount(const char* _string) const
{
CodePoint codepoint = 0;
uint32_t state = 0;
uint32_t lineCount = 1;
for (; *_string; ++_string)
{
if (utf8_decode(&state, (uint32_t*)&codepoint, *_string) == UTF8_ACCEPT)
{
if(codepoint == L'\n')
{
++lineCount;
}
}
}
BX_CHECK(state == UTF8_ACCEPT, "The string is not well-formed");
return lineCount;
}
uint32_t TextLineMetrics::getLineCount(const wchar_t* _string) const
{
uint32_t lineCount = 1;
for ( ;*_string != L'\0'; ++_string)
{
if(*_string == L'\n')
{
++lineCount;
}
}
return lineCount;
}
void TextLineMetrics::getSubText(const char* _string, uint32_t _firstLine, uint32_t _lastLine, const char*& _begin, const char*& _end)
{
CodePoint codepoint = 0;
uint32_t state = 0;
// y is bottom of a text line
uint32_t currentLine = 0;
while(*_string && (currentLine < _firstLine) )
{
for (; *_string; ++_string)
{
if (utf8_decode(&state, (uint32_t*)&codepoint, *_string) == UTF8_ACCEPT)
{
if (codepoint == L'\n')
{
++currentLine;
++_string;
break;
}
}
}
}
BX_CHECK(state == UTF8_ACCEPT, "The string is not well-formed");
_begin = _string;
while ( (*_string) && (currentLine < _lastLine) )
{
for (; *_string; ++_string)
{
if(utf8_decode(&state, (uint32_t*)&codepoint, *_string) == UTF8_ACCEPT)
{
if(codepoint == L'\n')
{
++currentLine;
++_string;
break;
}
}
}
}
BX_CHECK(state == UTF8_ACCEPT, "The string is not well-formed");
_end = _string;
}
void TextLineMetrics::getSubText(const wchar_t* _string, uint32_t _firstLine, uint32_t _lastLine, const wchar_t*& _begin, const wchar_t*& _end)
{
uint32_t currentLine = 0;
while ( (*_string != L'\0') && (currentLine < _firstLine) )
{
for ( ;*_string != L'\0'; ++_string)
{
if(*_string == L'\n')
{
++currentLine;
++_string;
break;
}
}
}
_begin = _string;
while ( (*_string != L'\0') && (currentLine < _lastLine) )
{
for ( ;*_string != L'\0'; ++_string)
{
if(*_string == L'\n')
{
++currentLine;
++_string;
break;
}
}
}
_end = _string;
}
void TextLineMetrics::getVisibleText(const char* _string, float _top, float _bottom, const char*& _begin, const char*& _end)
{
CodePoint codepoint = 0;
uint32_t state = 0;
// y is bottom of a text line
float y = m_lineHeight;
while (*_string && (y < _top) )
{
for (; *_string; ++_string)
{
if(utf8_decode(&state, (uint32_t*)&codepoint, *_string) == UTF8_ACCEPT)
{
if(codepoint == L'\n')
{
y += m_lineHeight;
++_string;
break;
}
}
}
}
BX_CHECK(state == UTF8_ACCEPT, "The string is not well-formed");
_begin = _string;
// y is now top of a text line
y -= m_lineHeight;
while ( (*_string) && (y < _bottom) )
{
for (; *_string; ++_string)
{
if(utf8_decode(&state, (uint32_t*)&codepoint, *_string) == UTF8_ACCEPT)
{
if(codepoint == L'\n')
{
y += m_lineHeight;
++_string;
break;
}
}
}
}
BX_CHECK(state == UTF8_ACCEPT, "The string is not well-formed");
_end = _string;
}
void TextLineMetrics::getVisibleText(const wchar_t* _string, float _top, float _bottom, const wchar_t*& _begin, const wchar_t*& _end)
{
// y is bottom of a text line
float y = m_lineHeight;
const wchar_t* _textEnd = _string + wcslen(_string);
while (y < _top)
{
for (const wchar_t* _current = _string; _current < _textEnd; ++_current)
{
if(*_current == L'\n')
{
y += m_lineHeight;
++_string;
break;
}
}
}
_begin = _string;
// y is now top of a text line
y -= m_lineHeight;
while (y < _bottom )
{
for (const wchar_t* _current = _string; _current < _textEnd; ++_current)
{
if(*_current == L'\n')
{
y += m_lineHeight;
++_string;
break;
}
}
}
_end = _string;
}