VSE: Media transform redesign

This patch changes behavior of strip transform and crop feature.

Purpose of this change is to allow display arbitrary portion of input
image, simplify user interface and workflow.
Offset and Crop values in old files are converted in versioning.
Offset animation is also converted. Crop animation and animation of
crop or offset enable properties is not taken into account

Changes in behavior and interface:
- If image is added to timeline it is scaled to fit inside preview area
while maintaining aspect ratio. Image is centered. This is considered
as a baseline for further transformation.
- Scale and rotation was added, so it is possible to transform image at
it's original resolution.
- Crop will not affect image transformation (does not move image).
- Values of Crop and Transform Position are in pixels, these values are
corrected if preview is fraction of project resolution.
- Transform and Mirror panel has been removed and new Transform panel
and Crop panel is moved to Adjust panel. Mirror is now part of new
Transform panel.

Technical changes:
- Preprocessing stage must work on duplicated image, because original is
cached. Previously Crop and Offset could run at once and required only
one duplication of image. This is not the case with new algorithms, so
duplication on demand is implemented. Transformation can read original
image and will output new image that is safe to modify. It should be
possible to add crop step to transform algorithm, so that Crop won't
require previous duplication though.
- Use Crop and Use Translation checkboxes were removed. Individual
values are compared to default values to check if image needs to be
processed. In case of transform this will be done also if resolution of
source.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D8393

2 files changed, 61 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_math_matrix.h b/source/blender/blenlib/BLI_math_matrix.h
index 9f6c56d698a..d971f48c4cf 100644
--- a/source/blender/blenlib/BLI_math_matrix.h
+++ b/source/blender/blenlib/BLI_math_matrix.h
@@ -322,9 +322,13 @@ void mat4_to_size(float size[3], const float M[4][4]);
 
 void mat4_to_size_fix_shear(float size[3], const float M[4][4]);
 
+void translate_m3(float mat[3][3], float tx, float ty);
 void translate_m4(float mat[4][4], float tx, float ty, float tz);
+void rotate_m3(float mat[3][3], const float angle);
 void rotate_m4(float mat[4][4], const char axis, const float angle);
+void rescale_m3(float mat[3][3], const float scale[2]);
 void rescale_m4(float mat[4][4], const float scale[3]);
+void transform_pivot_set_m3(float mat[3][3], const float pivot[2]);
 void transform_pivot_set_m4(float mat[4][4], const float pivot[3]);
 
 void mat3_to_rot_size(float rot[3][3], float size[3], const float mat3[3][3]);
@@ -334,6 +338,10 @@ void mat4_decompose(float loc[3], float quat[4], float size[3], const float wmat
 
 void mat3_polar_decompose(const float mat3[3][3], float r_U[3][3], float r_P[3][3]);
 
+void loc_rot_size_to_mat3(float R[3][3],
+                          const float loc[2],
+                          const float angle,
+                          const float size[2]);
 void loc_rot_size_to_mat4(float R[4][4],
                           const float loc[3],
                           const float rot[3][3],
diff --git a/source/blender/blenlib/intern/math_matrix.c b/source/blender/blenlib/intern/math_matrix.c
index cf6945529f2..9769d2baf9b 100644
--- a/source/blender/blenlib/intern/math_matrix.c
+++ b/source/blender/blenlib/intern/math_matrix.c
@@ -2223,6 +2223,12 @@ void scale_m4_fl(float R[4][4], float scale)
   R[3][0] = R[3][1] = R[3][2] = 0.0;
 }
 
+void translate_m3(float mat[3][3], float tx, float ty)
+{
+  mat[2][0] += (tx * mat[0][0] + ty * mat[1][0]);
+  mat[2][1] += (tx * mat[0][1] + ty * mat[1][1]);
+}
+
 void translate_m4(float mat[4][4], float Tx, float Ty, float Tz)
 {
   mat[3][0] += (Tx * mat[0][0] + Ty * mat[1][0] + Tz * mat[2][0]);
@@ -2230,6 +2236,18 @@ void translate_m4(float mat[4][4], float Tx, float Ty, float Tz)
   mat[3][2] += (Tx * mat[0][2] + Ty * mat[1][2] + Tz * mat[2][2]);
 }
 
+void rotate_m3(float mat[3][3], const float angle)
+{
+  const float angle_cos = cosf(angle);
+  const float angle_sin = sinf(angle);
+
+  for (int col = 0; col < 3; col++) {
+    float temp = angle_cos * mat[0][col] + angle_sin * mat[1][col];
+    mat[1][col] = -angle_sin * mat[0][col] + angle_cos * mat[1][col];
+    mat[0][col] = temp;
+  }
+}
+
 /* TODO: enum for axis? */
 /**
  * Rotate a matrix in-place.
@@ -2275,6 +2293,12 @@ void rotate_m4(float mat[4][4], const char axis, const float angle)
   }
 }
 
+void rescale_m3(float mat[3][3], const float scale[2])
+{
+  mul_v3_fl(mat[0], scale[0]);
+  mul_v3_fl(mat[1], scale[1]);
+}
+
 /** Scale a matrix in-place. */
 void rescale_m4(float mat[4][4], const float scale[3])
 {
@@ -2305,6 +2329,20 @@ void transform_pivot_set_m4(float mat[4][4], const float pivot[3])
   mul_m4_m4m4(mat, mat, tmat);
 }
 
+void transform_pivot_set_m3(float mat[3][3], const float pivot[2])
+{
+  float tmat[3][3];
+
+  unit_m3(tmat);
+
+  copy_v2_v2(tmat[2], pivot);
+  mul_m3_m3m3(mat, tmat, mat);
+
+  /* invert the matrix */
+  negate_v2(tmat[2]);
+  mul_m3_m3m3(mat, mat, tmat);
+}
+
 void blend_m3_m3m3(float out[3][3],
                    const float dst[3][3],
                    const float src[3][3],
@@ -2485,6 +2523,21 @@ bool equals_m4m4(const float mat1[4][4], const float mat2[4][4])
 }
 
 /**
+ * Make a 3x3 matrix out of 3 transform components.
+ * Matrices are made in the order: `loc * rot * scale`
+ */
+void loc_rot_size_to_mat3(float R[3][3],
+                          const float loc[2],
+                          const float angle,
+                          const float size[2])
+{
+  unit_m3(R);
+  translate_m3(R, loc[0], loc[1]);
+  rotate_m3(R, angle);
+  rescale_m3(R, size);
+}
+
+/**
  * Make a 4x4 matrix out of 3 transform components.
  * Matrices are made in the order: `scale * rot * loc`
  */