vpGetImage - get a field of the intermediate image
vpGetImage(vpc, image, width, height, scan_bytes, pixel_type,
int width, height;
int pixel_type, image_type;
vpc VolPack context from vpCreateContext.
image 2D array for storing result image.
width Width of array in pixels.
height Height of array in pixels.
Number of bytes per scanline in array.
Code indicating the format of each pixel in the array.
Code indicating the source of the image data (VP_IMAGE_BUFFER or
This is a debugging function. It is used to retrieve the contents of
one of the temporary rendering buffers used during rendering, namely
the intermediate image or the shadow buffer. Rendering consists of two
stages: the volume is resampled and composited into the intermediate
image to produce a distorted volume rendering, and then the
intermediate image is warped into the final image. If shadows are
enabled then the shadow buffer is used during the first stage to
incrementally compute which voxels are illuminated by the light source.
This function returns images produced during the first stage, before
the final warp.
This function may be called after a call to one of the rendering
routines (see vpRenderRawVolume(3)). If the image_type argument is
VP_IMAGE_BUFFER then data will be copied from the intermediate image.
The pixel_type argument specifies what information to copy and the
format for storing the data in the output array. The possible values
for pixel_type are the same as for the pixel_type argument to
vpSetImage. For instance, use VP_LUMINANCE to extract the grayscale
intensity (assuming the current shader produces grayscale pixels).
If the image_type argument is VP_SHADOW_BUFFER then data will be copied
from the shadow buffer. The only valid option for pixel_type is
VP_ALPHA, since no color information is stored in the shadow buffer.
See vpSetImage for details on the pixel formats, the layout of the
output array, and the remaining arguments.
To find the required size for the result array, use vpGeti with the
VP_INTERMEDIATE_WIDTH and VP_INTERMEDIATE_HEIGHT options (when
image_type is VP_IMAGE_BUFFER) or the VP_SHADOW_WIDTH and
VP_SHADOW_HEIGHT options (when image_type is VP_SHADOW_BUFFER).
The normal return value is VP_OK. The following error return values
The destination array size is incorrect or there is no
The field argument is invalid.
VolPack(3), vpRenderRawVolume(3), vpGeti(3)