cpp/21_207/page_manual_initrenderstruct.html

// This example samples the given shader in UV space.


// init the shader


InitRenderStruct irs { doc };


COLORSPACETRANSFORMATION transform = COLORSPACETRANSFORMATION::NONE;

// check if linear workflow is enabled

if (irs.linear_workflow)

  transform = COLORSPACETRANSFORMATION::LINEAR_TO_SRGB;


const INITRENDERRESULT res = shader->InitRender(irs);

if (res != INITRENDERRESULT::OK)

  return maxon::UnexpectedError(MAXON_SOURCE_LOCATION);


// sample the shader in UV space


ChannelData channelData;

channelData.off = 0;

channelData.scale = 0;

channelData.t = doc->GetTime().Get();

channelData.texflag = CALC_TEXINFO(0, CHANNEL_COLOR);


channelData.d  = Vector { 1, 1, 1 };

channelData.n  = Vector { 0, 1, 0 };

channelData.vd = nullptr; // VolumeData is nullptr


for (Int32 y = 0; y < height; ++y)

{

  for (Int32 x = 0; x < width; ++x)

  {

    // generate UV coordinates

    const Float64 xFloat = (Float64)x;

    const Float64 yFloat = (Float64)y;

    const Float64 u = xFloat / widthFloat;

    const Float64 v = yFloat / heightFloat;


    channelData.p.x = u;

    channelData.p.y = v;

    channelData.p.z = 0.0f;


    const Vector color = shader->Sample(&channelData);

    const Vector transformedColor = TransformColor(color, transform).Clamp01();


    // write into the given BaseBitmap

    const Int32 r = SAFEINT32(transformedColor.x * COLORTOINT_MULTIPLIER);

    const Int32 g = SAFEINT32(transformedColor.y * COLORTOINT_MULTIPLIER);

    const Int32 b = SAFEINT32(transformedColor.z * COLORTOINT_MULTIPLIER);


    bitmap->SetPixel(x, y, r, g, b);

  }

}


// free shader resources

shader->FreeRender();