kc3-lang/ftgl/src/FTSimpleLayout.cpp

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• Hash : 8e7cd218
  Author :
  Date : 2003-04-06T19:18:48
  

  - Added FTLayout.h, FTSimpleLayout.h and FTSimpleLayout.cpp to implement a framework for layout managers and an implementation of a simple layout manager.

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• src/FTSimpleLayout.cpp

• #include "FTSimpleLayout.h"
  
  #include "FTFont.h"
  #include "FTGlyphContainer.h"
  #include "FTBBox.h"
  
  #include <ctype.h>
  
  
  FTSimpleLayout::FTSimpleLayout() {
     currentFont = NULL;
     lineLength = 100.0f;
     alignment = ALIGN_LEFT;
     lineSpacing = 1.0f;
  } /* FTSimpleLayout::FTSimpleLayout() */
  
  void FTSimpleLayout::BBox(const char *String,float& llx, float& lly, float& llz, float& urx, float& ury, float& urz) {
     FTBBox bounds; 
     
     WrapText(String,&bounds); 
     llx = bounds.lowerX; lly = bounds.lowerY; llz = bounds.lowerZ;
     urx = bounds.upperX; ury = bounds.upperY; urz = bounds.upperZ;
  } /* FTSimpleLayout::BBox() */
  
  void FTSimpleLayout::BBox(const wchar_t *String,float& llx, float& lly, float& llz, float& urx, float& ury, float& urz) {
     FTBBox bounds; 
     
     WrapText(String,&bounds); 
     llx = bounds.lowerX; lly = bounds.lowerY; llz = bounds.lowerZ;
     urx = bounds.upperX; ury = bounds.upperY; urz = bounds.upperZ;
  } /* FTSimpleLayout::BBox() */
  
  void FTSimpleLayout::Render(const char *String) {
     pen.x = pen.y = 0.0f;
     WrapText(String,NULL);
  } /* FTSimpleLayout::Render() */
  
  void FTSimpleLayout::Render(const wchar_t* String) {
     pen.x = pen.y = 0.0f;
     WrapText(String,NULL);
  } /* FTSimpleLayout::Render() */
  
  void FTSimpleLayout::WrapText(const char *Buffer,FTBBox *bounds) {
     int breakIdx = 0;					// The index of the last break character
     int lineStart = 0;				// The character index of the line start
     float nextStart = 0.0;			// The total width of the line being generated
     float breakWidth = 0.0;			// The width of the line up to the last word break
     float currentWidth = 0.0;		// The width of all characters on the line being generated
     float prevWidth;					// The width of all characters but the current glyph
     float wordLength = 0.0;			// The length of the block since the last break character
     float glyphWidth,advance;
     FTBBox glyphBounds;
     /* Reset the pen position */
     pen.y = 0;
     
     if (bounds) {
        bounds->Invalidate();
     } /* If we have bounds mark them invalid (if bounds) */
     
     for (int charIdx = 0;Buffer[charIdx];charIdx++) {         
        /* Find the width of the current glyph */
        CheckGlyph(currentFont,Buffer[charIdx]);
        glyphBounds = GetGlyphs(currentFont)->BBox(Buffer[charIdx]);
        glyphWidth = glyphBounds.upperX - glyphBounds.lowerX;
        
        advance = GetGlyphs(currentFont)->Advance(Buffer[charIdx],Buffer[charIdx + 1]);
        prevWidth = currentWidth;
        /* Compute the width of all glyphs up to the end of Buffer[charIdx] */
        currentWidth = nextStart + glyphWidth;
        /* Compute the position of the next glyph */
        nextStart += advance;
        
        if ((currentWidth > lineLength) || (Buffer[charIdx] == '\n')) {
           /* A non whitespace character has exceeded the line length.  Or a */
           /* newline character has forced a line break.  Output the last    */
           /* line and start a new line after the break character.           */
           
           if (!breakIdx || (Buffer[charIdx] == '\n')) {
              /* Break on the previous character */
              breakIdx = charIdx - 1;
              breakWidth = prevWidth;
              /* None of the previous word will be carried to the next line */
              wordLength = 0;
              /* If the current character is a newline discard it's advance */
              if (Buffer[charIdx] == '\n') advance = 0;
           } /* If we have not yet found a break break on the last character (if !breakIdx) */
           
           float remainingWidth = lineLength - breakWidth;
  
           /* Render the current substring */
           if (Buffer[breakIdx + 1] == '\n') {
              breakIdx++;
              OutputWrapped(Buffer,lineStart,breakIdx -1,remainingWidth,bounds);
           } else {
              OutputWrapped(Buffer,lineStart,breakIdx   ,remainingWidth,bounds);
           } /* If the break character is a newline do not render it (if Buffer[charIdx]) */
  
           /* Store the start of the next line */
           lineStart = breakIdx + 1;
           // TODO: Is Height() the right value here?
           pen.y -= GetCharSize(currentFont).Height()*lineSpacing;
           /* The current width is the width since the last break */
           nextStart = wordLength + advance;
           wordLength += advance;
           currentWidth = wordLength + advance;
           /* Reset the safe break for the next line */
           breakIdx = 0;
        } else if (isspace(Buffer[charIdx])) {
           /* This is the last word break position */
           wordLength = 0;
           breakIdx = charIdx;
  
           if (!charIdx || !isspace(Buffer[charIdx - 1])) {
              /* Record the width of the start of the block */
              breakWidth = currentWidth;
           } /* Check to see if this is the first whitespace character in a run (if !isspace()) */
        } else {
           wordLength += advance;
        } /* See if Buffer[charIdx] is a space, a break or a regular charactger (if/elseif/else Buffer[]) */
     } /* Scan the input for all characters that need output (for charIdx) */
     
     float remainingWidth = lineLength - currentWidth;
     /* Render any remaining text on the last line */
     if (alignment == ALIGN_JUST) {
        alignment = ALIGN_LEFT;
        OutputWrapped(Buffer,lineStart,-1,remainingWidth,bounds);
        alignment = ALIGN_JUST;
     } else {
        OutputWrapped(Buffer,lineStart,-1,remainingWidth,bounds);
     } /* Disable justification for the last row (if/else Alignemnt) */
  } /* FTSimpleLayout::WrapText() */
  
  void FTSimpleLayout::WrapText(const wchar_t* Buffer,FTBBox *bounds) {
     int breakIdx = 0;					// The index of the last break character
     int lineStart = 0;				// The character index of the line start
     float nextStart = 0.0;			// The total width of the line being generated
     float breakWidth = 0.0;			// The width of the line up to the last word break
     float currentWidth = 0.0;		// The width of all characters on the line being generated
     float prevWidth;					// The width of all characters but the current glyph
     float wordLength = 0.0;			// The length of the block since the last break character
     float glyphWidth,advance;
     FTBBox glyphBounds;
     /* Reset the pen position */
     pen.y = 0;
     
     if (bounds) {
        bounds->Invalidate();
     } /* If we have bounds mark them invalid (if bounds) */
     
     for (int charIdx = 0;Buffer[charIdx];charIdx++) {         
        /* Find the width of the current glyph */
        CheckGlyph(currentFont,Buffer[charIdx]);
        glyphBounds = GetGlyphs(currentFont)->BBox(Buffer[charIdx]);
        glyphWidth = glyphBounds.upperX - glyphBounds.lowerX;
        
        advance = GetGlyphs(currentFont)->Advance(Buffer[charIdx],Buffer[charIdx + 1]);
        prevWidth = currentWidth;
        /* Compute the width of all glyphs up to the end of Buffer[charIdx] */
        currentWidth = nextStart + glyphWidth;
        /* Compute the position of the next glyph */
        nextStart += advance;
        
        if ((currentWidth > lineLength) || (Buffer[charIdx] == '\n')) {
           /* A non whitespace character has exceeded the line length.  Or a */
           /* newline character has forced a line break.  Output the last    */
           /* line and start a new line after the break character.           */
           
           if (!breakIdx || (Buffer[charIdx] == '\n')) {
              /* Break on the previous character */
              breakIdx = charIdx - 1;
              breakWidth = prevWidth;
              /* None of the previous word will be carried to the next line */
              wordLength = 0;
              /* If the current character is a newline discard it's advance */
              if (Buffer[charIdx] == '\n') advance = 0;
           } /* If we have not yet found a break break on the last character (if !breakIdx) */
           
           float remainingWidth = lineLength - breakWidth;
  
           /* Render the current substring */
           if (Buffer[breakIdx + 1] == '\n') {
              breakIdx++;
              OutputWrapped(Buffer,lineStart,breakIdx -1,remainingWidth,bounds);
           } else {
              OutputWrapped(Buffer,lineStart,breakIdx   ,remainingWidth,bounds);
           } /* If the break character is a newline do not render it (if Buffer[charIdx]) */
  
           /* Store the start of the next line */
           lineStart = breakIdx + 1;
           // TODO: Is Height() the right value here?
           pen.y -= GetCharSize(currentFont).Height()*lineSpacing;
           /* The current width is the width since the last break */
           nextStart = wordLength + advance;
           wordLength += advance;
           currentWidth = wordLength + advance;
           /* Reset the safe break for the next line */
           breakIdx = 0;
        } else if (isspace(Buffer[charIdx])) {
           /* This is the last word break position */
           wordLength = 0;
           breakIdx = charIdx;
  
           if (!charIdx || !isspace(Buffer[charIdx - 1])) {
              /* Record the width of the start of the block */
              breakWidth = currentWidth;
           } /* Check to see if this is the first whitespace character in a run (if !isspace()) */
        } else {
           wordLength += advance;
        } /* See if Buffer[charIdx] is a space, a break or a regular charactger (if/elseif/else Buffer[]) */
     } /* Scan the input for all characters that need output (for charIdx) */
     
     float remainingWidth = lineLength - currentWidth;
     /* Render any remaining text on the last line */
     if (alignment == ALIGN_JUST) {
        alignment = ALIGN_LEFT;
        OutputWrapped(Buffer,lineStart,-1,remainingWidth,bounds);
        alignment = ALIGN_JUST;
     } else {
        OutputWrapped(Buffer,lineStart,-1,remainingWidth,bounds);
     } /* Disable justification for the last row (if/else Alignemnt) */
  } /* FTSimpleLayout::WrapText() */
  
  void FTSimpleLayout::OutputWrapped(const char *Buffer,const int StartIdx,const int EndIdx,const float RemainingWidth,FTBBox *bounds) {
     float distributeWidth = 0.0;
     switch (alignment) {
        case ALIGN_LEFT:
           pen.x = 0; 
           break;
        case ALIGN_CENTER:
           pen.x = RemainingWidth/2; 
           break;
        case ALIGN_RIGHT:
           pen.x = RemainingWidth;
           break;
        case ALIGN_JUST:
           pen.x = 0;
           distributeWidth = RemainingWidth;
           break;
     } /* Allign the text according as specified by Alignment (switch Alignment) */
  
     if (bounds) {
        float llx,lly,llz,urx,ury,urz;
        currentFont->BBox(Buffer,StartIdx,EndIdx,llx,lly,llz,urx,ury,urz);
  
        /* Add the extra space to the upper x dimension */
        urx += distributeWidth;
        // TODO: It's a little silly to convert from a FTBBox to floats and back again, but I don't want to 
        //       implement yet another method for finding the bounding box as a BBox.
        FTBBox temp(llx,lly,llz,urx,ury,urz);
        temp.Move(FTPoint(pen.x,pen.y,0.0f));
        
        if (!bounds->IsValid()) {
           *bounds = temp;
        } else {
           *bounds += temp;
        } /* See if this is the first area to be added to the bounds (if/else bounds) */
     } else {
        RenderSpace(Buffer,StartIdx,EndIdx,distributeWidth);
     } /* If we have bounds expand them by the lines bounds, otherwise render the line (if/else bounds) */
  } /* FTSimpleLayout::OutputWrapped() */
  
  void FTSimpleLayout::OutputWrapped(const wchar_t *Buffer,const int StartIdx,const int EndIdx,const float RemainingWidth,FTBBox *bounds) {
     float distributeWidth = 0.0;
     switch (alignment) {
        case ALIGN_LEFT:
           pen.x = 0; 
           break;
        case ALIGN_CENTER:
           pen.x = RemainingWidth/2; 
           break;
        case ALIGN_RIGHT:
           pen.x = RemainingWidth;
           break;
        case ALIGN_JUST:
           pen.x = 0;
           distributeWidth = RemainingWidth;
           break;
     } /* Allign the text according as specified by Alignment (switch Alignment) */
  
     if (bounds) {
        float llx,lly,llz,urx,ury,urz;
        currentFont->BBox(Buffer,StartIdx,EndIdx,llx,lly,llz,urx,ury,urz);
  
        /* Add the extra space to the upper x dimension */
        urx += distributeWidth;
        // TODO: It's a little silly to convert from a FTBBox to floats and back again, but I don't want to 
        //       implement yet another method for finding the bounding box as a BBox.
        FTBBox temp(llx,lly,llz,urx,ury,urz);
        temp.Move(FTPoint(pen.x,pen.y,0.0f));
        
        if (!bounds->IsValid()) {
           *bounds = temp;
        } else {
           *bounds += temp;
        } /* See if this is the first area to be added to the bounds (if/else bounds) */
     } else {
        RenderSpace(Buffer,StartIdx,EndIdx,distributeWidth);
     } /* If we have bounds expand them by the lines bounds, otherwise render the line (if/else bounds) */
  } /* FTSimpleLayout::OutputWrapped() */
  
  void FTSimpleLayout::RenderSpace(const char *String,const int StartIdx,const int EndIdx,const float ExtraSpace) {
     float space = 0.0;
     
     if (ExtraSpace > 0.0) {
        int numSpaces = 0;
  
        for (int idx = StartIdx;((EndIdx < 0) && String[idx]) || ((EndIdx >= 0) && (idx <= EndIdx));idx++) {
           if ((idx > StartIdx) && !isspace(String[idx]) && isspace(String[idx - 1])) {
              numSpaces++;
           } /* If this is the end of a space block increment the counter (if isspace()) */
        } /* Count the number of space blocks in the input (for idx) */
        
        space = ExtraSpace/numSpaces;
     } /* If there is space to distribute count the number of spaces (if ExtraSpace) */
     
     for (int idx = StartIdx;((EndIdx < 0) && String[idx]) || ((EndIdx >= 0) && (idx <= EndIdx));idx++) {
        if ((idx > StartIdx) && !isspace(String[idx]) && isspace(String[idx - 1])) {
           pen.x += space;
        } /* If this is the end of a space block distribute the extra space into it (if isspace()) */
  
        DoRender(currentFont,String[idx],String[idx + 1]);
     } /* Output all characters of the string (for idx) */
  } /* FTSimpleLayout::RenderSpace() */
  
  void FTSimpleLayout::RenderSpace(const wchar_t *String,const int StartIdx,const int EndIdx,const float ExtraSpace) {
     float space = 0.0;
     
     if (ExtraSpace > 0.0) {
        int numSpaces = 0;
  
        for (int idx = StartIdx;((EndIdx < 0) && String[idx]) || ((EndIdx >= 0) && (idx <= EndIdx));idx++) {
           if ((idx > StartIdx) && !isspace(String[idx]) && isspace(String[idx - 1])) {
              numSpaces++;
           } /* If this is the end of a space block increment the counter (if isspace()) */
        } /* Count the number of space blocks in the input (for idx) */
        
        space = ExtraSpace/numSpaces;
     } /* If there is space to distribute count the number of spaces (if ExtraSpace) */
     
     for (int idx = StartIdx;((EndIdx < 0) && String[idx]) || ((EndIdx >= 0) && (idx <= EndIdx));idx++) {
        if ((idx > StartIdx) && !isspace(String[idx]) && isspace(String[idx - 1])) {
           pen.x += space;
        } /* If this is the end of a space block distribute the extra space into it (if isspace()) */
  
        DoRender(currentFont,String[idx],String[idx + 1]);
     } /* Output all characters of the string (for idx) */
  } /* FTSimpleLayout::RenderSpace() */
  

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