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The SoShaderProgram class is used to specify a set of vertex/geometry/fragment objects. More...
#include <Inventor/nodes/SoShaderProgram.h>
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 () |
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.
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 [] }
SoShaderProgram::SoShaderProgram | ( | void | ) |
Constructor.
SoShaderProgram::~SoShaderProgram | ( | ) | [protected, virtual] |
Destructor.
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.
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.
The shader objects.
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