Cycles: Expose volume voxel data interpolation to the interface

It is per-material setting which could be found under the Volume settings
in the material and world context buttons.

There could still be some code-wise improvements, like using variable-size
macro for interp3d instead of having interp3d_ex to which you can pass the
interpolation method.

1 files changed, 8 insertions, 0 deletions

diff --git a/intern/cycles/kernel/kernel_compat_cpu.h b/intern/cycles/kernel/kernel_compat_cpu.h
index e00caf5a720..37cba03ff97 100644
--- a/intern/cycles/kernel/kernel_compat_cpu.h
+++ b/intern/cycles/kernel/kernel_compat_cpu.h
@@ -151,6 +151,13 @@ template<typename T> struct texture_image  {
 
 	ccl_always_inline float4 interp_3d(float x, float y, float z, bool periodic = false)
 	{
+		return interp_3d_ex(x, y, z, interpolation, periodic);
+	}
+
+	ccl_always_inline float4 interp_3d_ex(float x, float y, float z,
+	                                      int interpolation = INTERPOLATION_LINEAR,
+	                                      bool periodic = false)
+	{
 		if(UNLIKELY(!data))
 			return make_float4(0.0f, 0.0f, 0.0f, 0.0f);
 
@@ -331,6 +338,7 @@ typedef texture_image<uchar4> texture_image_uchar4;
 #define kernel_tex_lookup(tex, t, offset, size) (kg->tex.lookup(t, offset, size))
 #define kernel_tex_image_interp(tex, x, y) ((tex < MAX_FLOAT_IMAGES) ? kg->texture_float_images[tex].interp(x, y) : kg->texture_byte_images[tex - MAX_FLOAT_IMAGES].interp(x, y))
 #define kernel_tex_image_interp_3d(tex, x, y, z) ((tex < MAX_FLOAT_IMAGES) ? kg->texture_float_images[tex].interp_3d(x, y, z) : kg->texture_byte_images[tex - MAX_FLOAT_IMAGES].interp_3d(x, y, z))
+#define kernel_tex_image_interp_3d_ex(tex, x, y, z, interpolation) ((tex < MAX_FLOAT_IMAGES) ? kg->texture_float_images[tex].interp_3d_ex(x, y, z, interpolation) : kg->texture_byte_images[tex - MAX_FLOAT_IMAGES].interp_3d_ex(x, y, z, interpolation))
 
 #define kernel_data (kg->__data)