Cycles: Add support for bindless textures.

This adds support for CUDA Texture objects (also known as Bindless textures) for Kepler GPUs (Geforce 6xx and above).
This is used for all 2D/3D textures, data still uses arrays as before.

User benefits:
* No more limits of image textures on Kepler.
 We had 5 float4 and 145 byte4 slots there before, now we have 1024 float4 and 1024 byte4.
 This can be extended further if we need to (just change the define).

* Single channel textures slots (byte and float) are now supported on Kepler as well (1024 slots for each type).

ToDo / Issues:
* 3D textures don't work yet, at least don't show up during render. I have no idea whats wrong yet.
* Dynamically allocate bindless_mapping array?

I hope Fermi still works fine, but that should be tested on a Fermi card before pushing to master.

Part of my GSoC 2016.

Reviewers: sergey, #cycles, brecht

Subscribers: swerner, jtheninja, brecht, sergey

Differential Revision: https://developer.blender.org/D1999

1 files changed, 14 insertions, 3 deletions

diff --git a/intern/cycles/kernel/svm/svm_voxel.h b/intern/cycles/kernel/svm/svm_voxel.h
index 85ba2f906fa..d2cc2c3730e 100644
--- a/intern/cycles/kernel/svm/svm_voxel.h
+++ b/intern/cycles/kernel/svm/svm_voxel.h
@@ -42,10 +42,21 @@ ccl_device void svm_node_tex_voxel(KernelGlobals *kg,
 		tfm.w = read_node_float(kg, offset);
 		co = transform_point(&tfm, co);
 	}
+	float4 r;
 #  if defined(__KERNEL_GPU__)
-	float4 r = volume_image_texture_3d(id, co.x, co.y, co.z);
-#  else
-	float4 r = kernel_tex_image_interp_3d(id, co.x, co.y, co.z);
+#    if __CUDA_ARCH__ >= 300
+	CUtexObject tex = kernel_tex_fetch(__bindless_mapping, id);
+	if(id < 2048) /* TODO(dingto): Make this a variable */
+		r = kernel_tex_image_interp_3d_float4(tex, co.x, co.y, co.z);
+	else {
+		float f = kernel_tex_image_interp_3d_float(tex, co.x, co.y, co.z);
+		r = make_float4(f, f, f, 1.0);
+	}
+#    else /* __CUDA_ARCH__ >= 300 */
+	r = volume_image_texture_3d(id, co.x, co.y, co.z);
+#    endif
+#  else /* __KERNEL_GPU__ */
+	r = kernel_tex_image_interp_3d(id, co.x, co.y, co.z);
 #  endif
 #else
 	float4 r = make_float4(0.0f, 0.0f, 0.0f, 0.0f);