Code refactor: add ProjectionTransform separate from regular Transform.

This is in preparation of making Transform affine only.

3 files changed, 177 insertions, 35 deletions

diff --git a/intern/cycles/util/CMakeLists.txt b/intern/cycles/util/CMakeLists.txt
index 66c4f22a7e2..24043e2231b 100644
--- a/intern/cycles/util/CMakeLists.txt
+++ b/intern/cycles/util/CMakeLists.txt
@@ -67,6 +67,7 @@ set(SRC_HEADERS
 	util_param.h
 	util_path.h
 	util_progress.h
+	util_projection.h
 	util_queue.h
 	util_rect.h
 	util_set.h
diff --git a/intern/cycles/util/util_projection.h b/intern/cycles/util/util_projection.h
new file mode 100644
index 00000000000..0b8ff032120
--- /dev/null
+++ b/intern/cycles/util/util_projection.h
@@ -0,0 +1,176 @@
+/*
+ * Copyright 2011-2018 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __UTIL_PROJECTION_H__
+#define __UTIL_PROJECTION_H__
+
+#include "util/util_transform.h"
+
+CCL_NAMESPACE_BEGIN
+
+/* Data Types */
+
+typedef struct ProjectionTransform {
+	float4 x, y, z, w; /* rows */
+
+#ifndef __KERNEL_GPU__
+	ProjectionTransform()
+	{
+	}
+
+	explicit ProjectionTransform(const Transform& tfm)
+	: x(tfm.x),
+	  y(tfm.y),
+	  z(tfm.z),
+	  w(tfm.w)
+	{
+	}
+#endif
+} ProjectionTransform;
+
+typedef struct PerspectiveMotionTransform {
+	ProjectionTransform pre;
+	ProjectionTransform post;
+} PerspectiveMotionTransform;
+
+/* Functions */
+
+ccl_device_inline float3 transform_perspective(const ProjectionTransform *t, const float3 a)
+{
+	float4 b = make_float4(a.x, a.y, a.z, 1.0f);
+	float3 c = make_float3(dot(t->x, b), dot(t->y, b), dot(t->z, b));
+	float w = dot(t->w, b);
+
+	return (w != 0.0f)? c/w: make_float3(0.0f, 0.0f, 0.0f);
+}
+
+ccl_device_inline float3 transform_perspective_direction(const ProjectionTransform *t, const float3 a)
+{
+	float3 c = make_float3(
+		a.x*t->x.x + a.y*t->x.y + a.z*t->x.z,
+		a.x*t->y.x + a.y*t->y.y + a.z*t->y.z,
+		a.x*t->z.x + a.y*t->z.y + a.z*t->z.z);
+
+	return c;
+}
+
+#ifndef __KERNEL_GPU__
+
+ccl_device_inline ProjectionTransform projection_transpose(const ProjectionTransform& a)
+{
+	ProjectionTransform t;
+
+	t.x.x = a.x.x; t.x.y = a.y.x; t.x.z = a.z.x; t.x.w = a.w.x;
+	t.y.x = a.x.y; t.y.y = a.y.y; t.y.z = a.z.y; t.y.w = a.w.y;
+	t.z.x = a.x.z; t.z.y = a.y.z; t.z.z = a.z.z; t.z.w = a.w.z;
+	t.w.x = a.x.w; t.w.y = a.y.w; t.w.z = a.z.w; t.w.w = a.w.w;
+
+	return t;
+}
+
+ccl_device_inline ProjectionTransform projection_inverse(const ProjectionTransform& a)
+{
+	Transform t = {a.x, a.y, a.z, a.w};
+	t = transform_inverse(t);
+	return ProjectionTransform(t);
+}
+
+ccl_device_inline ProjectionTransform make_projection(
+	float a, float b, float c, float d,
+	float e, float f, float g, float h,
+	float i, float j, float k, float l,
+	float m, float n, float o, float p)
+{
+	ProjectionTransform t;
+
+	t.x.x = a; t.x.y = b; t.x.z = c; t.x.w = d;
+	t.y.x = e; t.y.y = f; t.y.z = g; t.y.w = h;
+	t.z.x = i; t.z.y = j; t.z.z = k; t.z.w = l;
+	t.w.x = m; t.w.y = n; t.w.z = o; t.w.w = p;
+
+	return t;
+}
+ccl_device_inline ProjectionTransform projection_identity()
+{
+	return make_projection(
+		1.0f, 0.0f, 0.0f, 0.0f,
+		0.0f, 1.0f, 0.0f, 0.0f,
+		0.0f, 0.0f, 1.0f, 0.0f,
+		0.0f, 0.0f, 0.0f, 1.0f);
+}
+
+ccl_device_inline ProjectionTransform operator*(const ProjectionTransform& a, const ProjectionTransform& b)
+{
+	ProjectionTransform c = projection_transpose(b);
+	ProjectionTransform t;
+
+	t.x = make_float4(dot(a.x, c.x), dot(a.x, c.y), dot(a.x, c.z), dot(a.x, c.w));
+	t.y = make_float4(dot(a.y, c.x), dot(a.y, c.y), dot(a.y, c.z), dot(a.y, c.w));
+	t.z = make_float4(dot(a.z, c.x), dot(a.z, c.y), dot(a.z, c.z), dot(a.z, c.w));
+	t.w = make_float4(dot(a.w, c.x), dot(a.w, c.y), dot(a.w, c.z), dot(a.w, c.w));
+
+	return t;
+}
+
+ccl_device_inline ProjectionTransform operator*(const ProjectionTransform& a, const Transform& b)
+{
+	return a * ProjectionTransform(b);
+}
+
+ccl_device_inline ProjectionTransform operator*(const Transform& a, const ProjectionTransform& b)
+{
+	return ProjectionTransform(a) * b;
+}
+
+ccl_device_inline void print_projection(const char *label, const ProjectionTransform& t)
+{
+	print_float4(label, t.x);
+	print_float4(label, t.y);
+	print_float4(label, t.z);
+	print_float4(label, t.w);
+	printf("\n");
+}
+
+ccl_device_inline ProjectionTransform projection_perspective(float fov, float n, float f)
+{
+	ProjectionTransform persp = make_projection(
+		1, 0, 0, 0,
+		0, 1, 0, 0,
+		0, 0, f / (f - n), -f*n / (f - n),
+		0, 0, 1, 0);
+
+	float inv_angle = 1.0f/tanf(0.5f*fov);
+
+	Transform scale = transform_scale(inv_angle, inv_angle, 1);
+
+	return scale * persp;
+}
+
+ccl_device_inline ProjectionTransform projection_orthographic(float znear, float zfar)
+{
+	Transform t =
+		transform_scale(1.0f, 1.0f, 1.0f / (zfar-znear)) *
+		transform_translate(0.0f, 0.0f, -znear);
+
+	return ProjectionTransform(t);
+}
+
+#endif /* __KERNEL_GPU__ */
+
+CCL_NAMESPACE_END
+
+#endif /* __UTIL_PROJECTION_H__ */
+
diff --git a/intern/cycles/util/util_transform.h b/intern/cycles/util/util_transform.h
index 1efe001f6a8..52022292d0b 100644
--- a/intern/cycles/util/util_transform.h
+++ b/intern/cycles/util/util_transform.h
@@ -47,22 +47,8 @@ typedef struct ccl_may_alias MotionTransform {
 	Transform post;
 } MotionTransform;
 
-typedef struct PerspectiveMotionTransform {
-	Transform pre;
-	Transform post;
-} PerspectiveMotionTransform;
-
 /* Functions */
 
-ccl_device_inline float3 transform_perspective(const Transform *t, const float3 a)
-{
-	float4 b = make_float4(a.x, a.y, a.z, 1.0f);
-	float3 c = make_float3(dot(t->x, b), dot(t->y, b), dot(t->z, b));
-	float w = dot(t->w, b);
-
-	return (w != 0.0f)? c/w: make_float3(0.0f, 0.0f, 0.0f);
-}
-
 ccl_device_inline float3 transform_point(const Transform *t, const float3 a)
 {
 	/* TODO(sergey): Disabled for now, causes crashes in certain cases. */
@@ -221,21 +207,6 @@ ccl_device_inline Transform transform_scale(float x, float y, float z)
 	return transform_scale(make_float3(x, y, z));
 }
 
-ccl_device_inline Transform transform_perspective(float fov, float n, float f)
-{
-	Transform persp = make_transform(
-		1, 0, 0, 0,
-		0, 1, 0, 0,
-		0, 0, f / (f - n), -f*n / (f - n),
-		0, 0, 1, 0);
-
-	float inv_angle = 1.0f/tanf(0.5f*fov);
-
-	Transform scale = transform_scale(inv_angle, inv_angle, 1);
-
-	return scale * persp;
-}
-
 ccl_device_inline Transform transform_rotate(float angle, float3 axis)
 {
 	float s = sinf(angle);
@@ -272,12 +243,6 @@ ccl_device_inline Transform transform_euler(float3 euler)
 		transform_rotate(euler.x, make_float3(1.0f, 0.0f, 0.0f));
 }
 
-ccl_device_inline Transform transform_orthographic(float znear, float zfar)
-{
-	return transform_scale(1.0f, 1.0f, 1.0f / (zfar-znear)) *
-		transform_translate(0.0f, 0.0f, -znear);
-}
-
 ccl_device_inline Transform transform_identity()
 {
 	return transform_scale(1.0f, 1.0f, 1.0f);