From 1289c4ee41288299509ef91ede05285a5beae734 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Wed, 30 Aug 2017 16:21:03 +0100
Subject: [PATCH] Added osgText::Font::s/getGlyphInterval(int) and
 GlyphTexture::s/getGlyphInterval(int) and internal support for clmapping
 positions of glyph images an defined intervals, defaults to 1.

---
 include/osgText/Font  |  6 ++++++
 include/osgText/Glyph |  5 +++++
 src/osgText/Font.cpp  |  2 ++
 src/osgText/Glyph.cpp | 23 ++++++++++++++---------
 4 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/include/osgText/Font b/include/osgText/Font
index 952a6fda4..369493891 100644
--- a/include/osgText/Font
+++ b/include/osgText/Font
@@ -122,6 +122,11 @@ public:
     void setGlyphImageMarginRatio(float margin);
     float getGlyphImageMarginRatio() const;
 
+    /** Set the interval that glyph positions are clamped to.
+      * Default interval is 1 texels.*/
+    void setGlyphInterval(int interval);
+    int getGlyphInterval() const;
+
 
     /** Set the size of texture to create to store the glyph images when rendering.
       * Note, this doesn't affect already created Texture Glhph's.*/
@@ -197,6 +202,7 @@ protected:
     FontResolution                  _fontSize;
     unsigned int                    _margin;
     float                           _marginRatio;
+    int                             _glyphInterval;
 
     unsigned int                    _textureWidthHint;
     unsigned int                    _textureHeightHint;
diff --git a/include/osgText/Glyph b/include/osgText/Glyph
index f08686841..bb7d5192a 100644
--- a/include/osgText/Glyph
+++ b/include/osgText/Glyph
@@ -260,6 +260,9 @@ public:
     void setGlyphImageMarginRatio(float margin) { _marginRatio = margin; }
     float getGlyphImageMarginRatio() const { return _marginRatio; }
 
+    void setGlyphInterval(int interval) { _interval = interval; }
+    int getGlyphInterval() const { return _interval; }
+
     bool getSpaceForGlyph(Glyph* glyph, int& posX, int& posY);
 
     void addGlyph(Glyph* glyph,int posX, int posY);
@@ -282,6 +285,8 @@ protected:
     // in the texture which could accommodate new glyphs.
     int _margin;
     float _marginRatio;
+    int _interval;
+
     int _usedY;
     int _partUsedX;
     int _partUsedY;
diff --git a/src/osgText/Font.cpp b/src/osgText/Font.cpp
index c06392640..155acadff 100644
--- a/src/osgText/Font.cpp
+++ b/src/osgText/Font.cpp
@@ -301,6 +301,7 @@ Font::Font(FontImplementation* implementation):
     osg::Object(true),
     _margin(1),
     _marginRatio(0.02),
+    _glyphInterval(1),
     _textureWidthHint(1024),
     _textureHeightHint(1024),
     _minFilterHint(osg::Texture::LINEAR_MIPMAP_LINEAR),
@@ -604,6 +605,7 @@ void Font::addGlyph(const FontResolution& fontRes, unsigned int charcode, Glyph*
         // reserve enough space for the glyphs.
         glyphTexture->setGlyphImageMargin(_margin);
         glyphTexture->setGlyphImageMarginRatio(_marginRatio);
+        glyphTexture->setGlyphInterval(_glyphInterval);
         glyphTexture->setTextureSize(_textureWidthHint,_textureHeightHint);
         glyphTexture->setFilter(osg::Texture::MIN_FILTER,_minFilterHint);
         glyphTexture->setFilter(osg::Texture::MAG_FILTER,_magFilterHint);
diff --git a/src/osgText/Glyph.cpp b/src/osgText/Glyph.cpp
index 3bc346c8f..2699b0627 100644
--- a/src/osgText/Glyph.cpp
+++ b/src/osgText/Glyph.cpp
@@ -31,6 +31,7 @@ using namespace std;
 GlyphTexture::GlyphTexture():
     _margin(1),
     _marginRatio(0.02f),
+    _interval(1),
     _usedY(0),
     _partUsedX(0),
     _partUsedY(0)
@@ -60,18 +61,22 @@ bool GlyphTexture::getSpaceForGlyph(Glyph* glyph, int& posX, int& posY)
     int width = glyph->s()+2*margin;
     int height = glyph->t()+2*margin;
 
-    // first check box (_partUsedX,_usedY) to (width,height)
-    if (width <= (getTextureWidth()-_partUsedX) &&
-        height <= (getTextureHeight()-_usedY))
+    int partUsedX = ((_partUsedX % _interval) == 0) ? _partUsedX : (((_partUsedX/_interval)+1)*_interval);
+    int partUsedY = ((_partUsedY % _interval) == 0) ? _partUsedY : (((_partUsedY/_interval)+1)*_interval);
+    int usedY = ((_usedY % _interval) == 0) ? _usedY : (((_usedY/_interval)+1)*_interval);
+
+    // first check box (partUsedX, usedY) to (width,height)
+    if (width <= (getTextureWidth()-partUsedX) &&
+        height <= (getTextureHeight()-usedY))
     {
         // can fit in existing row.
 
         // record the position in which the texture will be stored.
-        posX = _partUsedX+margin;
-        posY = _usedY+margin;
+        posX = partUsedX+margin;
+        posY = usedY+margin;
 
         // move used markers on.
-        _partUsedX += width;
+        _partUsedX = posX+width;
         if (_usedY+height>_partUsedY) _partUsedY = _usedY+height;
 
         return true;
@@ -83,14 +88,14 @@ bool GlyphTexture::getSpaceForGlyph(Glyph* glyph, int& posX, int& posY)
     {
         // can fit next row.
         _partUsedX = 0;
-        _usedY = _partUsedY;
+        _usedY = partUsedY;
 
         posX = _partUsedX+margin;
         posY = _usedY+margin;
 
         // move used markers on.
-        _partUsedX += width;
-        if (_usedY+height>_partUsedY) _partUsedY = _usedY+height;
+        _partUsedX = posX+width;
+        _partUsedY = _usedY+height;
 
         return true;
     }