Code refactor: avoid motion transform copy, remove unused curved code.

The purpose of the previous code refactoring is to make the code more readable,
but combined with this change benchmarks also render about 2-3% faster with an
NVIDIA Titan Xp.

1 files changed, 26 insertions, 25 deletions

diff --git a/intern/cycles/util/util_transform.h b/intern/cycles/util/util_transform.h
index ac0804a7227..1efe001f6a8 100644
--- a/intern/cycles/util/util_transform.h
+++ b/intern/cycles/util/util_transform.h
@@ -455,40 +455,45 @@ ccl_device_inline void transform_compose(Transform *tfm, const Transform *decomp
 	tfm->w = make_float4(0.0f, 0.0f, 0.0f, 1.0f);
 }
 
-/* Disabled for now, need arc-length parametrization for constant speed motion.
- * #define CURVED_MOTION_INTERPOLATE */
+ccl_device void transform_motion_interpolate(Transform *tfm, const ccl_global MotionTransform *motion, float t)
+{
+	Transform decomp;
+
+	/* linear interpolation for rotation and scale */
+	if(t < 0.5f) {
+		t *= 2.0f;
+
+		decomp.x = quat_interpolate(motion->pre.x, motion->mid.x, t);
+		decomp.y = (1.0f - t)*motion->pre.y + t*motion->mid.y;
+		decomp.z = (1.0f - t)*motion->pre.z + t*motion->mid.z;
+		decomp.w = (1.0f - t)*motion->pre.w + t*motion->mid.w;
+	}
+	else {
+		t = (t - 0.5f)*2.0f;
+
+		decomp.x = quat_interpolate(motion->mid.x, motion->post.x, t);
+		decomp.y = (1.0f - t)*motion->mid.y + t*motion->post.y;
+		decomp.z = (1.0f - t)*motion->mid.z + t*motion->post.z;
+		decomp.w = (1.0f - t)*motion->mid.w + t*motion->post.w;
+	}
+
+	/* compose rotation, translation, scale into matrix */
+	transform_compose(tfm, &decomp);
+}
 
-ccl_device void transform_motion_interpolate(Transform *tfm, const MotionTransform *motion, float t)
+ccl_device void transform_motion_interpolate_constant(Transform *tfm, ccl_constant MotionTransform *motion, float t)
 {
 	/* possible optimization: is it worth it adding a check to skip scaling?
 	 * it's probably quite uncommon to have scaling objects. or can we skip
 	 * just shearing perhaps? */
 	Transform decomp;
 
-#ifdef CURVED_MOTION_INTERPOLATE
-	/* 3 point bezier curve interpolation for position */
-	float3 Ppre = float4_to_float3(motion->pre.y);
-	float3 Pmid = float4_to_float3(motion->mid.y);
-	float3 Ppost = float4_to_float3(motion->post.y);
-
-	float3 Pcontrol = 2.0f*Pmid - 0.5f*(Ppre + Ppost);
-	float3 P = Ppre*t*t + Pcontrol*2.0f*t*(1.0f - t) + Ppost*(1.0f - t)*(1.0f - t);
-
-	decomp.y.x = P.x;
-	decomp.y.y = P.y;
-	decomp.y.z = P.z;
-#endif
-
 	/* linear interpolation for rotation and scale */
 	if(t < 0.5f) {
 		t *= 2.0f;
 
 		decomp.x = quat_interpolate(motion->pre.x, motion->mid.x, t);
-#ifdef CURVED_MOTION_INTERPOLATE
-		decomp.y.w = (1.0f - t)*motion->pre.y.w + t*motion->mid.y.w;
-#else
 		decomp.y = (1.0f - t)*motion->pre.y + t*motion->mid.y;
-#endif
 		decomp.z = (1.0f - t)*motion->pre.z + t*motion->mid.z;
 		decomp.w = (1.0f - t)*motion->pre.w + t*motion->mid.w;
 	}
@@ -496,11 +501,7 @@ ccl_device void transform_motion_interpolate(Transform *tfm, const MotionTransfo
 		t = (t - 0.5f)*2.0f;
 
 		decomp.x = quat_interpolate(motion->mid.x, motion->post.x, t);
-#ifdef CURVED_MOTION_INTERPOLATE
-		decomp.y.w = (1.0f - t)*motion->mid.y.w + t*motion->post.y.w;
-#else
 		decomp.y = (1.0f - t)*motion->mid.y + t*motion->post.y;
-#endif
 		decomp.z = (1.0f - t)*motion->mid.z + t*motion->post.z;
 		decomp.w = (1.0f - t)*motion->mid.w + t*motion->post.w;
 	}