From Pavel Moloshtan, add support to osg::Texture files for GL_ARB_shadow_ambinet support

AUTHORS.txt

@@ -11,7 +11,7 @@ Robert Osfield <robert@openscenegraph.com>
         - 2nd iteration of shadow occlusion culling.
         - documentation?!
         - visual studio workspace files/unix makefiles.
-        - project adim & lead.
+        - project admin & lead.
 
 Don Burns <don@andesengineering.com>
         - Open Producer
@@ -124,7 +124,11 @@ Ruben Lopez <ryu@gpul.org>
         - Inventor ascii/VRML 1.0 loader.
 
 Pavel Moloshtan <pasha@moloshtan.com>
-        - Support for LWO2 format in the LightWave loader.
+        - First version of LightWave LWO2 format in lwo plugin.
+        - Support of GL_ARB_occlusion_query in osg::Drawable.
+        - Support of GL_ARB_shadow in osg::Texture, osgdepthtexture example.
+        - Support of GL_ARB_shadow_ambient in osg::Texture.
+        - Improvement to the ive plugin.
 
 Daniel Sjölie <deepone@acc.umu.se>
         - Support for multitextured flt files.

include/osg/Texture

@@ -82,6 +82,9 @@
 #define GL_COMPARE_R_TO_TEXTURE_ARB       0x884E
 #endif
 
+#ifndef TEXTURE_COMPARE_FAIL_VALUE_ARB
+#define TEXTURE_COMPARE_FAIL_VALUE_ARB    0x80BF
+#endif
 
 namespace osg {
 
@@ -91,7 +94,6 @@ class SG_EXPORT Texture : public osg::StateAttribute
 
     public :
     
-    
         Texture();
 
         /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
@@ -266,7 +268,10 @@ class SG_EXPORT Texture : public osg::StateAttribute
         void setShadowTextureMode(ShadowTextureMode mode) { _shadow_texture_mode = mode; }
         ShadowTextureMode getShadowTextureMode() { return _shadow_texture_mode; }
 
-
+        // set value of TEXTURE_COMPARE_FAIL_VALUE_ARB texture parameter
+        // http://oss.sgi.com/projects/ogl-sample/registry/ARB/shadow_ambient.txt
+        void setShadowAmbient(float shadow_ambient) { _shadow_ambient = shadow_ambient; }
+        float getShadowAmbient() { return _shadow_ambient; }
         
         /** Texture is pure virtual base class, apply must be overriden. */
         virtual void apply(State& state) const = 0;
@@ -315,6 +320,9 @@ class SG_EXPORT Texture : public osg::StateAttribute
                 void setShadowSupported(bool flag) { _isShadowSupported = flag; }
                 bool isShadowSupported() const { return _isShadowSupported; }
 
+                void setShadowAmbientSupported(bool flag) { _isShadowAmbientSupported = flag; }
+                bool isShadowAmbientSupported() const { return _isShadowAmbientSupported; }
+
                 void setMaxTextureSize(GLint maxsize) { _maxTextureSize=maxsize; }
                 GLint maxTextureSize() const { return _maxTextureSize; }
 
@@ -342,6 +350,7 @@ class SG_EXPORT Texture : public osg::StateAttribute
                 bool    _isTextureBorderClampSupported;
                 bool    _isGenerateMipMapSupported;
                 bool    _isShadowSupported;
+                bool    _isShadowAmbientSupported;
                 
                 GLint   _maxTextureSize;
 
@@ -415,6 +424,7 @@ class SG_EXPORT Texture : public osg::StateAttribute
         bool                _use_shadow_comparison;
         ShadowCompareFunc   _shadow_compare_func;
         ShadowTextureMode   _shadow_texture_mode;
+        float               _shadow_ambient;
 
     public:
     

src/osg/Texture.cpp

@@ -178,7 +178,8 @@ Texture::Texture():
             _internalFormat(0),
             _use_shadow_comparison(false),
             _shadow_compare_func(LEQUAL),
-            _shadow_texture_mode(LUMINANCE)
+            _shadow_texture_mode(LUMINANCE),
+            _shadow_ambient(0)
 {
 }
 
@@ -198,7 +199,8 @@ Texture::Texture(const Texture& text,const CopyOp& copyop):
             _internalFormat(text._internalFormat),
             _use_shadow_comparison(text._use_shadow_comparison),
             _shadow_compare_func(text._shadow_compare_func),
-            _shadow_texture_mode(text._shadow_texture_mode)
+            _shadow_texture_mode(text._shadow_texture_mode),
+            _shadow_ambient(text._shadow_ambient)
 {
 }
 
@@ -224,6 +226,7 @@ int Texture::compareTexture(const Texture& rhs) const
     COMPARE_StateAttribute_Parameter(_use_shadow_comparison)
     COMPARE_StateAttribute_Parameter(_shadow_compare_func)
     COMPARE_StateAttribute_Parameter(_shadow_texture_mode)
+    COMPARE_StateAttribute_Parameter(_shadow_ambient)
     
     return 0;
 }
@@ -494,6 +497,13 @@ void Texture::applyTexParameters(GLenum target, State& state) const
             glTexParameteri(target, GL_TEXTURE_COMPARE_MODE_ARB, GL_COMPARE_R_TO_TEXTURE_ARB);
             glTexParameteri(target, GL_TEXTURE_COMPARE_FUNC_ARB, _shadow_compare_func);
             glTexParameteri(target, GL_DEPTH_TEXTURE_MODE_ARB, _shadow_texture_mode);
+
+            // if ambient value is 0 - it is default behaviour of GL_ARB_shadow
+            // no need for GL_ARB_shadow_ambient in this case
+            if (extensions->isShadowAmbientSupported() && _shadow_ambient > 0)
+              {
+                glTexParameterf(target, TEXTURE_COMPARE_FAIL_VALUE_ARB, _shadow_ambient);
+              }
           }
         else 
           {
@@ -1038,6 +1048,9 @@ Texture::Extensions::Extensions(const Extensions& rhs):
     _maxTextureSize = rhs._maxTextureSize;
 
     _glCompressedTexImage2D = rhs._glCompressedTexImage2D;
+
+    _isShadowSupported = rhs._isShadowSupported;
+    _isShadowAmbientSupported = rhs._isShadowAmbientSupported;
 }
 
 void Texture::Extensions::lowestCommonDenominator(const Extensions& rhs)
@@ -1059,6 +1072,9 @@ void Texture::Extensions::lowestCommonDenominator(const Extensions& rhs)
     if (!rhs._glCompressedTexImage2D) _glCompressedTexImage2D = 0;
     if (!rhs._glCompressedTexSubImage2D) _glCompressedTexSubImage2D = 0;
     if (!rhs._glGetCompressedTexImage) _glGetCompressedTexImage = 0;
+
+    if (!rhs._isShadowSupported) _isShadowSupported = 0;
+    if (!rhs._isShadowAmbientSupported) _isShadowAmbientSupported = 0;
 }
 
 void Texture::Extensions::setupGLExtenions()
@@ -1076,7 +1092,7 @@ void Texture::Extensions::setupGLExtenions()
     _isGenerateMipMapSupported = (strncmp((const char*)glGetString(GL_VERSION),"1.4",3)>=0) ||
                                   isGLExtensionSupported("GL_SGIS_generate_mipmap");
     _isShadowSupported = isGLExtensionSupported("GL_ARB_shadow");
-
+    _isShadowAmbientSupported = isGLExtensionSupported("GL_ARB_shadow_ambient");
 
     glGetIntegerv(GL_MAX_TEXTURE_SIZE,&_maxTextureSize);