Shader Writing and Integration

Shader color and scalar results can be checked for illegal not-a-number (NaN, for example the square root of a negative number) results with -message phen debug -. NaNs typically cause unexpected black or white pixels.
New modes for mi_query were added:

miQ_FINALGATHER_STATE

miQ_FUNC_TAG

miQ_FUNC_CALLTYPE

miQ_PIXEL_SAMPLE
Here is the complete list of new shader and integration interface functions:

mi_opacity_set

mi_opacity_get

mi_shaderstate_set

mi_shaderstate_get

mi_shaderstate_enumerate

mi_finalgather_store

mi_ray_falloff

mi_ray_offset

mi_raster_unit

mi_mem_memory_limit

mi_job_memory_limit is obsolete and was removed.
A number of bitmap arguments of type miUlong were changed to miUint, because miUlong is now a 64-bit integer on 64-bit platforms.
The shader state variable dot_nd is now computed even if the light is rejected because there is no surface, like in a volume shader.
The cnst array in the miApprox data structure was changed from doubles to floats to make room for more options. This requires a recompilation of geometry shaders that access these fields (which is rather unlikely).
The callback installed by the mi_disp_stream_cb_begin integration function receives full frame buffers instead of small rectangle-sized image scraps. The lower left pixel of each received rectangle is now at ( xl, yl) instead of (0, 0) in the image tag provided to the callback.