NAME

vzTMShader - A general purpose shader to be used with the vzTMRenderAction.

INHERITS FROM

vzShader

HEADER FILE

#include <Volumizer2/TMShader.h>

PUBLIC METHOD SUMMARY

vzTMShader (

);

void setShapeCallbacks (

vzTMShaderCB preCB, vzTMShaderCB postCB, void* userData);

void getShapeCallbacks (

vzTMShaderCB& preCB, vzTMShaderCB& postCB, void*& userData);

void setSliceCallbacks (

int numCB, vzTMShaderCB* callbacks, void* userData);

void getSliceCallbacks (

int& numCB, vzTMShaderCB*& callbacks, void*& userData);

PROTECTED METHOD SUMMARY

virtual ~vzTMShader (

);

CLASS DESCRIPTION

The vzTMShader class provides a general purpose multi-pass shader which allows applications to apply arbitrary shading to shapes being rendered using the vzTMRenderAction. The vzTMRenderAction can be used to bind the appropriate resources that it manages for the application. This can be done using the following callback -

typedef bool (*vzTMBindParameterCB)(const char *name, vzTMShaderData *shaderData, vzTMShaderOp operation = VZ_TM_BIND);

The above callbacks are used to bind the volume texture and the lookup table (given by the respective parameter names). The callbacks can also be used to simply enable or disable the OpenGL state for the parameters managed by the TMRenderAction, i.e. volume textures and lookup tables.

METHOD DESCRIPTIONS

   vzTMShader()

vzTMShader (

);

Constructor.

   ~vzTMShader()

virtual ~vzTMShader (

);

Destructor.

   getShapeCallbacks()

void getShapeCallbacks (

vzTMShaderCB& preCB, vzTMShaderCB& postCB, void*& userData);

Get the pre and post shape callbacks.

   getSliceCallbacks()

void getSliceCallbacks (

int& numCB, vzTMShaderCB*& callbacks, void*& userData);

Get the per-slice callbacks.

   setShapeCallbacks()

void setShapeCallbacks (

vzTMShaderCB preCB, vzTMShaderCB postCB, void* userData);

Sets the callbacks invoked for each shape before and after the shape is rendered.The callbacks are defined as -

typedef void (*vzTMShaderCB)(vzTMShaderData *shaderData);

For example -

void preShape(vzTMShaderData *shaderData) {

    // Enable volume texture parameter
    shaderData->bindVolumeTextureCB("volume", shaderData, VZ_TM_ENABLE);
    
    // Bind the "volume" texture 
    if(!shaderData->bindVolumeTextureCB("volume", shaderData, VZ_TM_BIND))
       vzError::error(VZ_OPERATION_FAILED,"Could not bind volume texture 'volume'");
}

void postShape(vzTMShaderData *shaderData) {

    // Disable the volume texture
    shaderData->bindVolumeTextureCB("volume", shaderData, VZ_TM_DISABLE);
}

   setSliceCallbacks()

void setSliceCallbacks (

int numCB, vzTMShaderCB* callbacks, void* userData);

Sets the pass description for the vzTMShader. The default number of callbacks is 0. The callbacks are defined as -

typedef void (*vzTMShaderCB)(vzTMShaderData *shaderData);

For example -

void pass1(vzTMShaderData *shaderData) {

    if(!shaderData->bindVolumeTextureCB("volume", shaderData))
       vzError::error(VZ_OPERATION_FAILED,"Could not bind volume texture 'volume'");
    
}

void pass2(vzTMShaderData *shaderData) {

    if(!shaderData->bindVolumeTextureCB("volume2", shaderData))
       vzError::error(VZ_OPERATION_FAILED,"Could not bind volume texture 'volume2'");
}

SEE ALSO

vzShader

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