matrix: track transform type

Introduce several matrix transform types and track type for matrix.
Could be usefull for activating some fastpath that depends on some
transform type.

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
diff --git a/src/shell.c b/src/shell.c
index dcbabf3..a99786b 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -1876,6 +1876,8 @@
 	} else {
 		/* construct x, y translation matrix */
 		weston_matrix_init(&shsurf->popup.parent_transform.matrix);
+		shsurf->popup.parent_transform.matrix.type =
+			WESTON_MATRIX_TRANSFORM_TRANSLATE;
 		shsurf->popup.parent_transform.matrix.d[12] =
 			parent->geometry.x;
 		shsurf->popup.parent_transform.matrix.d[13] =
@@ -2502,10 +2504,7 @@
 			&shsurf->rotation.transform.matrix;
 
 		weston_matrix_init(&rotate->rotation);
-		rotate->rotation.d[0] = dx / r;
-		rotate->rotation.d[4] = -dy / r;
-		rotate->rotation.d[1] = -rotate->rotation.d[4];
-		rotate->rotation.d[5] = rotate->rotation.d[0];
+		weston_matrix_rotate_xy(&rotate->rotation, dx / r, dy / r);
 
 		weston_matrix_init(matrix);
 		weston_matrix_translate(matrix, -cx, -cy, 0.0f);
@@ -2600,17 +2599,11 @@
 		struct weston_matrix inverse;
 
 		weston_matrix_init(&inverse);
-		inverse.d[0] = dx / r;
-		inverse.d[4] = dy / r;
-		inverse.d[1] = -inverse.d[4];
-		inverse.d[5] = inverse.d[0];
+		weston_matrix_rotate_xy(&inverse, dx / r, -dy / r);
 		weston_matrix_multiply(&surface->rotation.rotation, &inverse);
 
 		weston_matrix_init(&rotate->rotation);
-		rotate->rotation.d[0] = dx / r;
-		rotate->rotation.d[4] = -dy / r;
-		rotate->rotation.d[1] = -rotate->rotation.d[4];
-		rotate->rotation.d[5] = rotate->rotation.d[0];
+		weston_matrix_rotate_xy(&rotate->rotation, dx / r, dy / r);
 	} else {
 		weston_matrix_init(&surface->rotation.rotation);
 		weston_matrix_init(&rotate->rotation);