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Font: Fix uploading missing glyphs during font rendering. (ref bug #226)
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@dscharrer
dscharrer committed Apr 20, 2012
1 parent 03bcef6 commit 2abfd30
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Showing 5 changed files with 233 additions and 178 deletions.
143 changes: 97 additions & 46 deletions src/graphics/font/Font.cpp
View file
Expand Up @@ -47,13 +47,13 @@ Font::Font(const res::path & fontFile, unsigned int fontSize, FT_Face face)

// Insert all the glyphs into texture pages
m_Textures = new PackedTexture(TEXTURE_SIZE, Image::Format_A8);
m_Textures->BeginPacking();

for(unsigned int chr = 32; chr < 256; ++chr) {
InsertGlyph(chr);
// Pre-load common glyphs
for(u32 chr = 32; chr < 256; ++chr) {
insertGlyph(chr);
}

m_Textures->EndPacking();
m_Textures->upload();
}

Font::~Font() {
Expand All @@ -64,36 +64,45 @@ Font::~Font() {
FT_Done_Face(m_FTFace);
}

bool Font::InsertGlyph(unsigned int character) {
void Font::insertPlaceholderGlyph(u32 character) {

// Glyp does not exist - insert something so we don't look it up for every render pass.
if(character < 256) {

// ignore non-displayable ANSI characters (and some more)
Glyph & glyph = m_Glyphs[character];
glyph.size = Vec2i::ZERO;
glyph.advance = Vec2f::ZERO;
glyph.lsb_delta = glyph.rsb_delta = 0;
glyph.draw_offset = Vec2i::ZERO;
glyph.uv_start = Vec2f::ZERO;
glyph.uv_end = Vec2f::ZERO;
glyph.texture = 0;

} else {
m_Glyphs[character] = m_Glyphs['?'];
LogWarning << "No glyph for character U+" << std::hex << character;
}
}

bool Font::insertGlyph(u32 character) {

FT_Error error;
FT_UInt glyphIndex = FT_Get_Char_Index(m_FTFace, character);
if(!glyphIndex) {
// Glyp does not exist - inser something so we don't look it up for every render pass.
if(character < 256) {
// ignore non-displayable ANSI characters (and some more)
Glyph & glyph = m_Glyphs[character];
glyph.size = Vec2i::ZERO;
glyph.advance = Vec2f::ZERO;
glyph.lsb_delta = glyph.rsb_delta = 0;
glyph.draw_offset = Vec2i::ZERO;
glyph.uv_start = Vec2f::ZERO;
glyph.uv_end = Vec2f::ZERO;
glyph.texture = 0;
} else {
m_Glyphs[character] = m_Glyphs['?'];
LogWarning << "No glyph for character U+" << std::hex << character;
}
insertPlaceholderGlyph(character);
return false;
}

error = FT_Load_Glyph(m_FTFace, glyphIndex, FT_LOAD_FORCE_AUTOHINT);
if(error) {
insertPlaceholderGlyph(character);
return false;
}

error = FT_Render_Glyph(m_FTFace->glyph, FT_RENDER_MODE_NORMAL);
if(error) {
insertPlaceholderGlyph(character);
return false;
}

Expand Down Expand Up @@ -125,16 +134,15 @@ bool Font::InsertGlyph(unsigned int character) {
unsigned char* dst = imgGlyph.GetData();
memcpy(dst, src, glyph.size.x * glyph.size.y);

int glyphPosX;
int glyphPosY;
m_Textures->InsertImage(imgGlyph, glyphPosX, glyphPosY, glyph.texture);
Vec2i offset;
m_Textures->insertImage(imgGlyph, glyph.texture, offset);

// Compute UV mapping for each glyph.
const float TEXTURE_SIZE = m_Textures->GetTextureSize();
glyph.uv_start.x = glyphPosX / TEXTURE_SIZE;
glyph.uv_start.y = glyphPosY / TEXTURE_SIZE;
glyph.uv_end.x = (glyphPosX + glyph.size.x) / TEXTURE_SIZE;
glyph.uv_end.y = (glyphPosY + glyph.size.y) / TEXTURE_SIZE;
const float textureSize = m_Textures->getTextureSize();
glyph.uv_start.x = offset.x / textureSize;
glyph.uv_start.y = offset.y / textureSize;
glyph.uv_end.x = (offset.x + glyph.size.x) / textureSize;
glyph.uv_end.y = (offset.y + glyph.size.y) / textureSize;
}

return true;
Expand All @@ -144,8 +152,8 @@ bool Font::WriteToDisk() {

bool ok = true;

for(unsigned int i = 0; i < m_Textures->GetTextureCount(); ++i) {
Texture2D & tex = m_Textures->GetTexture(i);
for(unsigned int i = 0; i < m_Textures->getTextureCount(); ++i) {
Texture2D & tex = m_Textures->getTexture(i);

std::stringstream ss;
ss << m_FTFace->family_name;
Expand All @@ -165,7 +173,7 @@ bool Font::WriteToDisk() {
return ok;
}

inline static bool read_utf8(string::const_iterator & it, string::const_iterator end, u32 & chr) {
inline static bool read_utf8(Font::text_iterator & it, Font::text_iterator end, u32 & chr) {

if(it == end) {
return false;
Expand Down Expand Up @@ -208,11 +216,56 @@ inline static bool read_utf8(string::const_iterator & it, string::const_iterator
return true;
}

void Font::Draw(int x, int y, const std::string& str, Color color) {
Draw(x, y, str.begin(), str.end(), color);
bool Font::insertMissingGlyphs(text_iterator begin, text_iterator end) {

u32 chr;
bool changed = false;

for(text_iterator it = begin; !read_utf8(it, end, chr); ) {
if(m_Glyphs.find(chr) == m_Glyphs.end()) {
if(chr >= 256 && insertGlyph(chr)) {
changed = true;
}
}
}

return changed;
}

void Font::Draw(int x, int y, std::string::const_iterator itStart, std::string::const_iterator itEnd, Color color) {
Font::glyph_iterator Font::getNextGlyph(text_iterator & it, text_iterator end) {

u32 chr;
if(!read_utf8(it, end, chr)) {
return m_Glyphs.end();
}

glyph_iterator glyph = m_Glyphs.find(chr);
if(glyph != m_Glyphs.end()) {
return glyph; // an existing glyph
}

if(chr < 256) {
// We pre-load all glyphs for charactres < 256, se there is no point in checking again
return m_Glyphs.end();
}

if(!insertGlyph(chr)) {
// No new glyph was inserted but the character was mapped to an existing one
return m_Glyphs.find(chr);
}

arx_assert(m_Glyphs.find(chr) != m_Glyphs.end());

// As we need to re-upload the textures now, first check for more missing glyphs
insertMissingGlyphs(it, end);

// Re-upload the changed textures
m_Textures->upload();

return m_Glyphs.find(chr); // the newly inserted glyph
}

void Font::Draw(int x, int y, text_iterator itStart, text_iterator itEnd, Color color) {

GRenderer->SetRenderState(Renderer::Lighting, false);
GRenderer->SetRenderState(Renderer::AlphaBlending, true);
Expand Down Expand Up @@ -245,17 +298,15 @@ void Font::Draw(int x, int y, std::string::const_iterator itStart, std::string::
FT_Pos prevRsbDelta = 0;

u32 chr;
for(string::const_iterator it = itStart; read_utf8(it, itEnd, chr); ) {
for(text_iterator it = itStart; it != itEnd; ) {

// Get glyph in glyph map
std::map<unsigned int, Glyph>::const_iterator itGlyph = m_Glyphs.find(chr);
glyph_iterator itGlyph = getNextGlyph(it, itEnd);
if(itGlyph == m_Glyphs.end()) {
if(chr < 256 || !InsertGlyph(chr) || (itGlyph = m_Glyphs.find(chr)) == m_Glyphs.end()) {
continue;
}
continue;
}

const Glyph & glyph = (*itGlyph).second;
const Glyph & glyph = itGlyph->second;

// Kerning
if(FT_HAS_KERNING(m_FTFace)) {
Expand All @@ -277,7 +328,7 @@ void Font::Draw(int x, int y, std::string::const_iterator itStart, std::string::
prevRsbDelta = glyph.rsb_delta;

// Draw
GRenderer->SetTexture(0, &m_Textures->GetTexture(glyph.texture));
GRenderer->SetTexture(0, &m_Textures->getTexture(glyph.texture));
GRenderer->DrawTexturedRect(((int)penX) + glyph.draw_offset.x, ((int)penY) - glyph.draw_offset.y, glyph.size.x, -glyph.size.y, glyph.uv_start.x, glyph.uv_end.y, glyph.uv_end.x, glyph.uv_start.y, color);

// Advance
Expand All @@ -303,7 +354,7 @@ Vec2i Font::GetTextSize(const std::string & str) {
return GetTextSize(str.begin(), str.end());
}

Vec2i Font::GetTextSize(std::string::const_iterator itStart, std::string::const_iterator itEnd) {
Vec2i Font::GetTextSize(text_iterator itStart, text_iterator itEnd) {

FT_UInt currentGlyph;
FT_UInt previousGlyph = 0;
Expand All @@ -314,16 +365,16 @@ Vec2i Font::GetTextSize(std::string::const_iterator itStart, std::string::const_
FT_Pos prevRsbDelta = 0;

u32 chr;
for(string::const_iterator it = itStart; read_utf8(it, itEnd, chr); ) {
for(text_iterator it = itStart; read_utf8(it, itEnd, chr); ) {

std::map<unsigned int, Glyph>::const_iterator itGlyph = m_Glyphs.find(chr);
glyph_iterator itGlyph = m_Glyphs.find(chr);
if(itGlyph == m_Glyphs.end()) {
if(chr < 256 || !InsertGlyph(chr) || (itGlyph = m_Glyphs.find(chr)) == m_Glyphs.end()) {
if(chr < 256 || !insertGlyph(chr) || (itGlyph = m_Glyphs.find(chr)) == m_Glyphs.end()) {
continue;
}
}

const Glyph & glyph = (*itGlyph).second;
const Glyph & glyph = itGlyph->second;

// Kerning
if(FT_HAS_KERNING(m_FTFace)) {
Expand Down
39 changes: 34 additions & 5 deletions src/graphics/font/Font.h
View file
Expand Up @@ -72,18 +72,24 @@ class Font : private boost::noncopyable {

public:

typedef std::string::const_iterator text_iterator;

const Info & GetInfo() const { return m_Info; }
const res::path & GetName() const { return m_Info.m_Name; }
unsigned int GetSize() const { return m_Info.m_Size; }

void Draw(const Vector2<int> &p, const std::string &str, const Color &color) {
void Draw(const Vector2<int> & p, const std::string & str, const Color & color) {
Draw(p.x, p.y, str, color);
}
void Draw(int pX, int pY, const std::string & str, Color color);
void Draw(int pX, int pY, std::string::const_iterator itStart, std::string::const_iterator itEnd, Color color);

void Draw(int pX, int pY, const std::string & str, Color color) {
Draw(pX, pY, str.begin(), str.end(), color);
}

void Draw(int pX, int pY, text_iterator itStart, text_iterator itEnd, Color color);

Vec2i GetTextSize(const std::string & str);
Vec2i GetTextSize(std::string::const_iterator itStart, std::string::const_iterator itEnd);
Vec2i GetTextSize(text_iterator itStart, text_iterator itEnd);

int GetLineHeight() const;

Expand All @@ -97,7 +103,22 @@ class Font : private boost::noncopyable {
Font(const res::path & fontFile, unsigned int fontSize, struct FT_FaceRec_ * face);
~Font();

bool InsertGlyph(unsigned int character);
//! Maps the given character to a placeholder glyph
void insertPlaceholderGlyph(u32 character);

/*!
* Inserts a single glyph
* Always maps the character to a glyph - uses a placeholder if there
* is no glyph for the given character
* \return true if the glyph textures were changed
*/
bool insertGlyph(u32 character);

/*!
* Inserts any missing glyphs for the characters in the UTF-8 string [begin, end)
* \return true if the glyph textures were changed
*/
bool insertMissingGlyphs(text_iterator begin, text_iterator end);

private:

Expand All @@ -106,6 +127,14 @@ class Font : private boost::noncopyable {

struct FT_FaceRec_ * m_FTFace;
std::map<unsigned int, Glyph> m_Glyphs;
typedef std::map<unsigned int, Glyph>::const_iterator glyph_iterator;

/*!
* Parses UTF-8 input and returns the glyph for the first character
* Inserts missing glyphs if possible.
* \return a glyph iterator or m_Glyphs.end()
*/
glyph_iterator getNextGlyph(text_iterator & it, text_iterator end);

class PackedTexture * m_Textures;

Expand Down

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