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NAME

       SoShaderProgram -

       The SoShaderProgram class is used to specify a set of vertex/geometry/fragment objects.

SYNOPSIS

       #include <Inventor/nodes/SoShaderProgram.h>

       Inherits SoNode.

   Public Member Functions
       virtual SoType getTypeId (void) const
           Returns the type identification of an object derived from a class inheriting SoBase.
           This is used for run-time type checking and 'downward' casting.
       SoShaderProgram (void)
       void setEnableCallback (SoShaderProgramEnableCB *cb, void *closure)
       virtual void GLRender (SoGLRenderAction *action)
       virtual void search (SoSearchAction *action)

   Static Public Member Functions
       static SoType getClassTypeId (void)
       static void initClass ()

   Public Attributes
       SoMFNode shaderObject

   Protected Member Functions
       virtual const SoFieldData * getFieldData (void) const
       virtual ~SoShaderProgram ()

   Static Protected Member Functions
       static const SoFieldData ** getFieldDataPtr (void)

   Additional Inherited Members

Detailed Description

       The SoShaderProgram class is used to specify a set of vertex/geometry/fragment objects.

       This node can store one of each of SoVertexShader, SoGeometryShader and SoFragmentShader
       in its shaderObject field. Coin will load all shader objects specified there, and attach
       all objects into a program before binding it as the current shader program.

       A typical scene graph with shaders will look something like this:

       Separator {
         ShaderProgram {
           shaderObject [
             VertexShader {
               sourceProgram "myvertexshader.glsl"
               parameter [
                 ShaderParameter1f { name "myvertexparam" value 1.0 }
               ]
             }
             FragmentShader {
               sourceProgram "myfragmentshader.glsl"
               parameter [
                 ShaderParameter1f { name "myfragmentparam" value 2.0 }
               ]
             }
           ]
         }
         Cube { }
       }

       This will render the Cube with the vertex and fragment shaders specified in
       myvertexshader.glsl and myfragmentshader.glsl. Coin also supports ARB shaders and Cg
       shaders (if the Cg library is installed). However, we recommend using GLSL since we will
       focus mostly on support this shader language.

       Coin defines some named parameters that can be added by the application programmer, and
       which will be automatically updated by Coin while traversing the scene graph.

       · coin_texunit[n]_model - Set to 0 when texturing is disabled, and to
         SoTextureImageElement::Model if there's a current texture on the state for unit n.
       · coin_light_model - Set to 1 for PHONG, 0 for BASE_COLOR lighting.
       Example scene graph that renders per-fragment OpenGL Phong lighting for one light source.
       The shaders assume the first light source is a directional light. This is the case if you
       open the file in a standard examiner viewer.
       The iv-file:
       Separator {
         ShaderProgram {
           shaderObject [
             VertexShader {
               sourceProgram "perpixel_vertex.glsl"
             }
             FragmentShader {
               sourceProgram "perpixel_fragment.glsl"
             }
           ]
         }
         Complexity { value 1.0 }
         Material { diffuseColor 1 0 0 specularColor 1 1 1 shininess 0.9 }
         Sphere { }

         Translation { translation 3 0 0 }
         Material { diffuseColor 0 1 0 specularColor 1 1 1 shininess 0.9 }
         Cone { }

         Translation { translation 3 0 0 }
         Material { diffuseColor 0.8 0.4 0.1 specularColor 1 1 1 shininess 0.9 }
         Cylinder { }
       }

       The vertex shader (perpixel_vertex.glsl):
       varying vec3 ecPosition3;
       varying vec3 fragmentNormal;

       void main(void)
       {
         vec4 ecPosition = gl_ModelViewMatrix * gl_Vertex;
         ecPosition3 = ecPosition.xyz / ecPosition.w;
         fragmentNormal = normalize(gl_NormalMatrix * gl_Normal);

         gl_Position = ftransform();
         gl_FrontColor = gl_Color;
       }

       The fragment shader (perpixel_vertex.glsl):
       varying vec3 ecPosition3;
       varying vec3 fragmentNormal;

       void DirectionalLight(in int i,
                             in vec3 normal,
                             inout vec4 ambient,
                             inout vec4 diffuse,
                             inout vec4 specular)
       {
         float nDotVP; // normal . light direction
         float nDotHV; // normal . light half vector
         float pf;     // power factor

         nDotVP = max(0.0, dot(normal, normalize(vec3(gl_LightSource[i].position))));
         nDotHV = max(0.0, dot(normal, vec3(gl_LightSource[i].halfVector)));

         if (nDotVP == 0.0)
           pf = 0.0;
         else
           pf = pow(nDotHV, gl_FrontMaterial.shininess);

         ambient += gl_LightSource[i].ambient;
         diffuse += gl_LightSource[i].diffuse * nDotVP;
         specular += gl_LightSource[i].specular * pf;
       }

       void main(void)
       {
         vec3 eye = -normalize(ecPosition3);
         vec4 ambient = vec4(0.0);
         vec4 diffuse = vec4(0.0);
         vec4 specular = vec4(0.0);
         vec3 color;

         DirectionalLight(0, normalize(fragmentNormal), ambient, diffuse, specular);

         color =
           gl_FrontLightModelProduct.sceneColor.rgb +
           ambient.rgb * gl_FrontMaterial.ambient.rgb +
           diffuse.rgb * gl_Color.rgb +
           specular.rgb * gl_FrontMaterial.specular.rgb;

         gl_FragColor = vec4(color, gl_Color.a);
       }

       FILE FORMAT/DEFAULTS:
       ShaderProgram {
         shaderObject []
       }

       See Also:
           SoShaderObject
           SoShaderProgram
       Since:
           Coin 2.5

Constructor & Destructor Documentation

   SoShaderProgram::SoShaderProgram (void)
       Constructor.
   SoShaderProgram::~SoShaderProgram () [protected],  [virtual]
       Destructor.

Member Function Documentation

   SoType SoShaderProgram::getTypeId (void) const [virtual]
       Returns the type identification of an object derived from a class inheriting SoBase. This
       is used for run-time type checking and 'downward' casting. Usage example:
       void foo(SoNode * node)
       {
         if (node->getTypeId() == SoFile::getClassTypeId()) {
           SoFile * filenode = (SoFile *)node;  // safe downward cast, knows the type
         }
       }
       For application programmers wanting to extend the library with new nodes, engines,
       nodekits, draggers or others: this method needs to be overridden in all subclasses. This
       is typically done as part of setting up the full type system for extension classes, which
       is usually accomplished by using the pre-defined macros available through for instance
       Inventor/nodes/SoSubNode.h (SO_NODE_INIT_CLASS and SO_NODE_CONSTRUCTOR for node classes),
       Inventor/engines/SoSubEngine.h (for engine classes) and so on.
       For more information on writing Coin extensions, see the class documentation of the
       toplevel superclasses for the various class groups.
       Implements SoBase.
   const SoFieldData * SoShaderProgram::getFieldData (void) const [protected],  [virtual]
       Returns a pointer to the class-wide field data storage object for this instance. If no
       fields are present, returns NULL.
       Reimplemented from SoFieldContainer.
   void SoShaderProgram::setEnableCallback (SoShaderProgramEnableCB *cb, void *closure)
       Adds a callback which is called every time this program is enabled/disabled.
   void SoShaderProgram::GLRender (SoGLRenderAction *action) [virtual]
       Action method for the SoGLRenderAction.
       This is called during rendering traversals. Nodes influencing the rendering state in any
       way or who wants to throw geometry primitives at OpenGL overrides this method.
       Reimplemented from SoNode.
   void SoShaderProgram::search (SoSearchAction *action) [virtual]
       Action method for SoSearchAction.
       Compares the search criteria from the action to see if this node is a match. Searching is
       done by matching up all criteria set up in the SoSearchAction -- if any of the requested
       criteria is a miss, the search is not deemed successful for the node.
       See Also:
           SoSearchAction
       Reimplemented from SoNode.

Member Data Documentation

   SoMFNode SoShaderProgram::shaderObject
       The shader objects.

Author

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