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
SoShaderProgram (void)
void setEnableCallback (SoShaderProgramEnableCB *cb, void *closure)
virtual void GLRender (SoGLRenderAction *action)
virtual void search (SoSearchAction *action)
Static Public Member Functions
static void initClass ()
Public Attributes
SoMFNode shaderObject
Protected Member Functions
virtual ~SoShaderProgram ()
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
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.
void SoShaderProgram::initClass (void) [static] Sets up initialization for
data common to all instances of this class, like submitting necessary
information to the Coin type system.
Reimplemented from SoNode.
Member Data Documentation
SoMFNode SoShaderProgram::shaderObject The shader objects.
Author
Generated automatically by Doxygen for Coin from the source code.