Added support for setting the texture subload width and height within

osg::Texture.  The values default to 0, and in this state they are
sizes of the glTexSubImage2D are taken from the source image size.  This
allows the previous setup with no settings for subload size to work as
before.

src/osg/Texture.cpp

@@ -42,6 +42,7 @@ Texture::Texture()
 
     _subloadMode   = OFF;
     _subloadOffsX = _subloadOffsY = 0;
+    _subloadWidth = _subloadHeight = 0;
 
     _borderColor.set(0.0, 0.0, 0.0, 0.0);//OpenGL default
 
@@ -95,6 +96,8 @@ int Texture::compare(const StateAttribute& sa) const
     COMPARE_StateAttribute_Parameter(_subloadMode)
     COMPARE_StateAttribute_Parameter(_subloadOffsX)
     COMPARE_StateAttribute_Parameter(_subloadOffsY)
+    COMPARE_StateAttribute_Parameter(_subloadWidth)
+    COMPARE_StateAttribute_Parameter(_subloadHeight)
 
     return 0; // passed all the above comparison macro's, must be equal.
 }
@@ -209,7 +212,7 @@ void Texture::apply(State& state) const
                 if (_texParamtersDirty) applyTexParameters(_target,state);
                 glTexSubImage2D(_target, 0,
                                 _subloadOffsX, _subloadOffsY,
-                                _image->s(), _image->t(),
+                                (_subloadWidth>0)?_subloadWidth:_image->s(), (_subloadHeight>0)?_subloadHeight:_image->t(),
                                 (GLenum) _image->pixelFormat(), (GLenum) _image->dataType(),
                                 _image->data());
                 // update the modified flag to show that the image has been loaded.
@@ -453,14 +456,17 @@ void Texture::applyTexImage(GLenum target, Image* image, State& state) const
         if (s_SGIS_GenMipmap && (_min_filter != LINEAR && _min_filter != NEAREST)) {
             glTexParameteri(target, GL_GENERATE_MIPMAP_SGIS, GL_TRUE);
         }
-
+        
+        GLsizei width = (_subloadWidth>0)?_subloadWidth:image->s();
+        GLsizei height = (_subloadHeight>0)?_subloadHeight:image->t();
+        
         // calculate texture dimension
         _textureWidth = 1;
-        for (; _textureWidth < (_subloadOffsX + image->s()); _textureWidth <<= 1)
+        for (; _textureWidth < (_subloadOffsX + width); _textureWidth <<= 1)
             ;
 
         _textureHeight = 1;
-        for (; _textureHeight < (_subloadOffsY + image->t()); _textureHeight <<= 1)
+        for (; _textureHeight < (_subloadOffsY + height); _textureHeight <<= 1)
             ;
 
         // reserve appropriate texture memory
@@ -471,7 +477,7 @@ void Texture::applyTexImage(GLenum target, Image* image, State& state) const
 
         glTexSubImage2D(target, 0,
                         _subloadOffsX, _subloadOffsY,
-                        image->s(), image->t(),
+                        width, height,
                         (GLenum) image->pixelFormat(), (GLenum) image->dataType(),
                         image->data());
     }

src/osg/TextureCubeMap.cpp

@@ -205,7 +205,7 @@ void TextureCubeMap::apply(State& state) const
                 {
                     glTexSubImage2D(faceTarget[n], 0,
                                     _subloadOffsX, _subloadOffsY,
-                                    _images[n]->s(), _images[n]->t(),
+                                    (_subloadWidth>0)?_subloadWidth:_images[n]->s(), (_subloadHeight>0)?_subloadHeight:_images[n]->t(),
                                     (GLenum) _images[n]->pixelFormat(), (GLenum) _images[n]->dataType(),
                                     _images[n]->data());
                     // update the modified flag to show that the image has been loaded.

src/osgPlugins/osg/Texture.cpp

@@ -128,6 +128,16 @@ bool Texture_readLocalData(Object& obj, Input& fr)
             iteratorAdvanced = true;
         }
     }
+    if (fr[0].matchWord("subloadSize"))
+    {
+        int width, height;
+        if (fr[1].getInt(width) && fr[2].getInt(height))
+        {
+            texture.setSubloadSize(width, height);
+            fr += 3;
+            iteratorAdvanced = true;
+        }
+    }
 
     return iteratorAdvanced;
 }
@@ -164,6 +174,10 @@ bool Texture_writeLocalData(const Object& obj, Output& fw)
         int x, y;
         texture.getSubloadOffset(x, y);
         fw.indent() << "subloadOffset " << x << " " << y << std::endl;
+
+        int width, height;
+        texture.getSubloadSize(width, height);
+        fw.indent() << "subloadSize " << width << " " << height << std::endl;
     }
 
     return true;