From 4c3f6004df1c4b3aba546f43857122c5dbb1a0d0 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 9 Dec 2003 11:31:33 +0000
Subject: [PATCH] Moved osgText across to create GL_ALPHA textures instead of
 GL_LUMINANCE_ALPHA

---
 include/osgText/Font                     |  3 ++
 src/osgPlugins/freetype/FreeTypeFont.cpp | 40 ++++++++++++++-
 src/osgText/DefaultFont.cpp              | 65 +++++++++++++++++-------
 src/osgText/Font.cpp                     |  4 ++
 4 files changed, 93 insertions(+), 19 deletions(-)

diff --git a/include/osgText/Font b/include/osgText/Font
index 9eacd62cd..a6ca7c345 100644
--- a/include/osgText/Font
+++ b/include/osgText/Font
@@ -19,6 +19,7 @@
 #include <osg/Texture2D>
 #include <osg/StateSet>
 #include <osg/buffered_value>
+#include <osg/TexEnv>
 
 #include <osgText/Export>
 
@@ -137,6 +138,8 @@ protected:
     osg::Texture::FilterMode        _minFilterHint;
     osg::Texture::FilterMode        _magFilterHint;
     
+    osg::ref_ptr<osg::TexEnv >      _texEnv;
+    
     osg::ref_ptr<FontImplementation> _implementation;
 
     
diff --git a/src/osgPlugins/freetype/FreeTypeFont.cpp b/src/osgPlugins/freetype/FreeTypeFont.cpp
index 8fed89968..aa274d69a 100644
--- a/src/osgPlugins/freetype/FreeTypeFont.cpp
+++ b/src/osgPlugins/freetype/FreeTypeFont.cpp
@@ -79,6 +79,10 @@ osgText::Font::Glyph* FreeTypeFont::getGlyph(unsigned int charcode)
 
     osg::ref_ptr<osgText::Font::Glyph> glyph = new osgText::Font::Glyph;
     
+
+
+//#define USE_LUMINANCE_ALPHA
+#ifdef USE_LUMINANCE_ALPHA
     unsigned int dataSize = width*height*2;
     unsigned char* data = new unsigned char[dataSize];
     
@@ -92,7 +96,7 @@ osgText::Font::Glyph* FreeTypeFont::getGlyph(unsigned int charcode)
                     data,
                     osg::Image::USE_NEW_DELETE,
                     1);
-
+    
     // skip the top margin        
     data += (margin*width)*2;
 
@@ -109,7 +113,41 @@ osgText::Font::Glyph* FreeTypeFont::getGlyph(unsigned int charcode)
         }
         data+=2*margin; // skip the right margin.
     }
+#else    
+    unsigned int dataSize = width*height;
+    unsigned char* data = new unsigned char[dataSize];
     
+
+    // clear the image to zeros.
+    for(unsigned char* p=data;p<data+dataSize;) { *p++ = 0; }
+
+    glyph->setImage(width,height,1,
+                    GL_ALPHA,
+                    GL_ALPHA,GL_UNSIGNED_BYTE,
+                    data,
+                    osg::Image::USE_NEW_DELETE,
+                    1);
+
+    glyph->setInternalTextureFormat(GL_ALPHA);
+
+    // skip the top margin        
+    data += (margin*width);
+
+    // copy image across to osgText::Glyph image.     
+    for(int r=sourceHeight-1;r>=0;--r)
+    {
+        data+=margin; // skip the left margin
+
+        unsigned char* ptr = buffer+r*pitch;
+        for(unsigned int c=0;c<sourceWidth;++c,++ptr)
+        {
+            (*data++)=*ptr;
+        }
+        data+=margin; // skip the right margin.
+    }
+#endif
+
+
     FT_Glyph_Metrics* metrics = &(glyphslot->metrics);
 
     glyph->setHorizontalBearing(osg::Vec2((float)metrics->horiBearingX/64.0f,(float)(metrics->horiBearingY-metrics->height)/64.0f)); // bottom left.
diff --git a/src/osgText/DefaultFont.cpp b/src/osgText/DefaultFont.cpp
index 5616be481..9f0fed4fa 100644
--- a/src/osgText/DefaultFont.cpp
+++ b/src/osgText/DefaultFont.cpp
@@ -195,10 +195,10 @@ void DefaultFont::constructGlyphs()
     unsigned int sourceWidth = 8;
     unsigned int sourceHeight = 12;
     
+//#define USE_LUMINANCE_ALPHA
+#ifdef USE_LUMINANCE_ALPHA
     _width = sourceWidth+2*_margin;
     _height = sourceHeight+2*_margin;
-    
-    
 
     // populate the glyph mp
     for(unsigned int i=32;i<127;i++)
@@ -229,22 +229,6 @@ void DefaultFont::constructGlyphs()
         for(unsigned int row=0;row<sourceHeight;++row,++ptr)
         {
             data+=2*_margin; // skip the left margin
-//             (*data++)=((*ptr)&128)?value_on:value_off;
-//             (*data++)=((*ptr)&128)?value_on:value_off;
-//             (*data++)=((*ptr)&64)?value_on:value_off;
-//             (*data++)=((*ptr)&64)?value_on:value_off;
-//             (*data++)=((*ptr)&32)?value_on:value_off;
-//             (*data++)=((*ptr)&32)?value_on:value_off;
-//             (*data++)=((*ptr)&16)?value_on:value_off;            
-//             (*data++)=((*ptr)&16)?value_on:value_off;            
-//             (*data++)=((*ptr)&8)?value_on:value_off;
-//             (*data++)=((*ptr)&8)?value_on:value_off;
-//             (*data++)=((*ptr)&4)?value_on:value_off;
-//             (*data++)=((*ptr)&4)?value_on:value_off;
-//             (*data++)=((*ptr)&2)?value_on:value_off;
-//             (*data++)=((*ptr)&2)?value_on:value_off;
-//             (*data++)=((*ptr)&1)?value_on:value_off;
-//             (*data++)=((*ptr)&1)?value_on:value_off;
             (*data++)=255;
             (*data++)=((*ptr)&128)?value_on:value_off;
             (*data++)=255;
@@ -263,7 +247,52 @@ void DefaultFont::constructGlyphs()
             (*data++)=((*ptr)&1)?value_on:value_off;
             data+=2*_margin; // skip the right margin.
         }
+#else        
+    _width = sourceWidth+2*_margin;
+    _height = sourceHeight+2*_margin;
+
+    // populate the glyph mp
+    for(unsigned int i=32;i<127;i++)
+    {
+        osg::ref_ptr<Glyph> glyph = new Glyph;
         
+        unsigned int dataSize = _width*_height;
+        unsigned char* data = new unsigned char[dataSize];
+
+        // clear the image to zeros.
+        for(unsigned char* p=data;p<data+dataSize;) { *p++ = 0; }
+        
+        glyph->setImage(_width,_height,1,
+                        GL_ALPHA,
+                        GL_ALPHA,GL_UNSIGNED_BYTE,
+                        data,
+                        osg::Image::USE_NEW_DELETE,
+                        1);
+
+        glyph->setInternalTextureFormat(GL_ALPHA);
+
+        // now populate data arry by converting bitmap into a luminance_alpha map.
+        unsigned char* ptr = rasters[i-32];
+        unsigned char value_on = 255;
+        unsigned char value_off = 0;
+
+        // skip the top margin        
+        data += (_margin*_width);
+        
+        for(unsigned int row=0;row<sourceHeight;++row,++ptr)
+        {
+            data+=_margin; // skip the left margin
+            (*data++)=((*ptr)&128)?value_on:value_off;
+            (*data++)=((*ptr)&64)?value_on:value_off;
+            (*data++)=((*ptr)&32)?value_on:value_off;
+            (*data++)=((*ptr)&16)?value_on:value_off;            
+            (*data++)=((*ptr)&8)?value_on:value_off;
+            (*data++)=((*ptr)&4)?value_on:value_off;
+            (*data++)=((*ptr)&2)?value_on:value_off;
+            (*data++)=((*ptr)&1)?value_on:value_off;
+            data+=_margin; // skip the right margin.
+        }
+#endif        
                         
         glyph->setHorizontalBearing(osg::Vec2(0.0f,0.0f)); // bottom left.
         glyph->setHorizontalAdvance((float)_width);
diff --git a/src/osgText/Font.cpp b/src/osgText/Font.cpp
index baee04865..edc99f6de 100644
--- a/src/osgText/Font.cpp
+++ b/src/osgText/Font.cpp
@@ -17,6 +17,8 @@
 
 #include <osg/State>
 #include <osg/Notify>
+#include <osg/TexEnv>
+
 #include <osgDB/ReadFile>
 #include <osgDB/FileUtils>
 #include <osg/GLU>
@@ -87,6 +89,7 @@ Font::Font(FontImplementation* implementation):
     _magFilterHint(osg::Texture::LINEAR)
 {
     setImplementation(implementation);
+    _texEnv = new osg::TexEnv(osg::TexEnv::BLEND);
 }
 
 Font::~Font()
@@ -259,6 +262,7 @@ void Font::addGlyph(unsigned int width, unsigned int height, unsigned int charco
         glyphTexture->setStateSet(stateset);
         stateset->setMode(GL_BLEND,osg::StateAttribute::ON);
         stateset->setTextureAttributeAndModes(0,glyphTexture,osg::StateAttribute::ON);
+        if (_texEnv.valid()) stateset->setTextureAttribute(0,_texEnv.get());
         stateset->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
 
         if (!glyphTexture->getSpaceForGlyph(glyph,posX,posY))