From 55c0afbe3ad2c6587f8c329a7dcc61284d8d18b9 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Sun, 20 May 2018 13:22:58 +0100
Subject: [PATCH] Restructed SCREEN auto scaling so that it's removes the
 rotation of the modelview matrix so that the XY coords of the text map
 directly to window xy coords for all text alignment types

---
 src/osgText/TextBase.cpp | 42 ++++++++++++++++++++--------------------
 1 file changed, 21 insertions(+), 21 deletions(-)

diff --git a/src/osgText/TextBase.cpp b/src/osgText/TextBase.cpp
index 889f3f0c0..bce1a3cd3 100644
--- a/src/osgText/TextBase.cpp
+++ b/src/osgText/TextBase.cpp
@@ -490,25 +490,20 @@ bool TextBase::computeMatrix(osg::Matrix& matrix, osg::State* state) const
         osg::Matrix modelview = state->getModelViewMatrix();
         osg::Matrix projection = state->getProjectionMatrix();
 
-        matrix.makeTranslate(-_offset);
+        osg::Matrix temp_matrix(modelview);
+        temp_matrix.setTrans(0.0,0.0,0.0);
 
         osg::Matrix rotate_matrix;
-        if (_autoRotateToScreen)
-        {
-            osg::Matrix temp_matrix(modelview);
-            temp_matrix.setTrans(0.0f,0.0f,0.0f);
+        rotate_matrix.invert(temp_matrix);
 
-            rotate_matrix.invert(temp_matrix);
-        }
-
-        matrix.postMultRotate(_rotation);
+        matrix.makeTranslate(-_offset);
 
         if (_characterSizeMode!=OBJECT_COORDS)
         {
             typedef osg::Matrix::value_type value_type;
 
-            value_type width = 1280.0f;
-            value_type height = 1024.0f;
+            value_type width = 1280.0;
+            value_type height = 1024.0;
 
             const osg::Viewport* viewport = state->getCurrentViewport();
             if (viewport)
@@ -518,6 +513,7 @@ bool TextBase::computeMatrix(osg::Matrix& matrix, osg::State* state) const
             }
 
             osg::Matrix mvpw = rotate_matrix * modelview * projection * osg::Matrix::scale(width/2.0, height/2.0, 1.0);
+
             osg::Vec3 origin = osg::Vec3(0.0, 0.0, 0.0) * mvpw;
             osg::Vec3 left = osg::Vec3(1.0, 0.0, 0.0) * mvpw - origin;
             osg::Vec3 up = osg::Vec3(0.0, 1.0, 0.0) * mvpw - origin;
@@ -529,12 +525,6 @@ bool TextBase::computeMatrix(osg::Matrix& matrix, osg::State* state) const
             value_type length_y = up.length();
             value_type scale_y = length_y>0.0 ? 1.0/length_y : 1.0;
 
-            value_type pixelSizeVert = _characterHeight / scale_y;
-
-            // avoid nasty math by preventing a divide by zero
-            if (pixelSizeVert == 0.0)
-               pixelSizeVert = 1.0;
-
             if (_glyphNormalized)
             {
                 osg::Vec3 scaleVec(_characterHeight/getCharacterAspectRatio(), _characterHeight, _characterHeight);
@@ -545,14 +535,24 @@ bool TextBase::computeMatrix(osg::Matrix& matrix, osg::State* state) const
             {
                 matrix.postMultScale(osg::Vec3(scale_x, scale_y, scale_x));
             }
-            else if (pixelSizeVert>getFontHeight())
+            else
             {
-                value_type scale_font = getFontHeight()/pixelSizeVert;
-                matrix.postMultScale(osg::Vec3f(scale_font, scale_font, scale_font));
-            }
+                value_type pixelSizeVert = _characterHeight / scale_y;
 
+                // avoid nasty math by preventing a divide by zero
+                if (pixelSizeVert == 0.0)
+                pixelSizeVert = 1.0;
+
+                if (pixelSizeVert>getFontHeight())
+                {
+                    value_type scale_font = getFontHeight()/pixelSizeVert;
+                    matrix.postMultScale(osg::Vec3f(scale_font, scale_font, scale_font));
+                }
+            }
         }
 
+        matrix.postMultRotate(_rotation);
+
         if (_autoRotateToScreen)
         {
             matrix.postMult(rotate_matrix);