From c99d76773509516f1543190d422fb3be4c3021a4 Mon Sep 17 00:00:00 2001 From: Alexander Gavrilov Date: Sat, 28 Nov 2020 14:50:03 +0300 Subject: Fix some naming and comments in F-Curve smoothing code. --- source/blender/blenkernel/intern/curve.c | 37 +++++++++++++++++++++++--------- 1 file changed, 27 insertions(+), 10 deletions(-) (limited to 'source/blender/blenkernel/intern/curve.c') diff --git a/source/blender/blenkernel/intern/curve.c b/source/blender/blenkernel/intern/curve.c index 091d542c43d..3ad94853078 100644 --- a/source/blender/blenkernel/intern/curve.c +++ b/source/blender/blenkernel/intern/curve.c @@ -3205,7 +3205,7 @@ static void calchandleNurb_intern(BezTriple *bezt, const float eps = 1e-5; /* assume normal handle until we check */ - bezt->f5 = HD_AUTOTYPE_NORMAL; + bezt->auto_handle_type = HD_AUTOTYPE_NORMAL; if (bezt->h1 == 0 && bezt->h2 == 0) { return; @@ -3298,7 +3298,7 @@ static void calchandleNurb_intern(BezTriple *bezt, float ydiff2 = next->vec[1][1] - bezt->vec[1][1]; if ((ydiff1 <= 0.0f && ydiff2 <= 0.0f) || (ydiff1 >= 0.0f && ydiff2 >= 0.0f)) { bezt->vec[0][1] = bezt->vec[1][1]; - bezt->f5 = HD_AUTOTYPE_SPECIAL; + bezt->auto_handle_type = HD_AUTOTYPE_LOCKED_FINAL; } else { /* handles should not be beyond y coord of two others */ if (ydiff1 <= 0.0f) { @@ -3325,7 +3325,7 @@ static void calchandleNurb_intern(BezTriple *bezt, float ydiff2 = next->vec[1][1] - bezt->vec[1][1]; if ((ydiff1 <= 0.0f && ydiff2 <= 0.0f) || (ydiff1 >= 0.0f && ydiff2 >= 0.0f)) { bezt->vec[2][1] = bezt->vec[1][1]; - bezt->f5 = HD_AUTOTYPE_SPECIAL; + bezt->auto_handle_type = HD_AUTOTYPE_LOCKED_FINAL; } else { /* handles should not be beyond y coord of two others */ if (ydiff1 <= 0.0f) { @@ -3673,24 +3673,33 @@ static bool tridiagonal_solve_with_limits(float *a, * | | | | | | * | | | | | | * | | | | | | - * |-------t1---------t2--------- ~ --------tN-------------------> time (co 0) + * |------dx1--------dx2--------- ~ -------dxN-------------------> time (co 0) + * + * Notation: + * + * x[i], y[i] - keyframe coordinates + * h[i] - right handle y offset from y[i] + * + * dx[i] = x[i] - x[i-1] + * dy[i] = y[i] - y[i-1] + * * Mathematical basis: * * 1. Handle lengths on either side of each point are connected by a factor * ensuring continuity of the first derivative: * - * l[i] = t[i+1]/t[i] + * l[i] = dx[i+1]/dx[i] * * 2. The tridiagonal system is formed by the following equation, which is derived * by differentiating the bezier curve and specifies second derivative continuity * at every point: * - * l[i]^2 * h[i-1] + (2*l[i]+2) * h[i] + 1/l[i+1] * h[i+1] = (y[i]-y[i-1])*l[i]^2 + y[i+1]-y[i] + * l[i]^2 * h[i-1] + (2*l[i]+2) * h[i] + 1/l[i+1] * h[i+1] = dy[i]*l[i]^2 + dy[i+1] * * 3. If this point is adjacent to a manually set handle with X size not equal to 1/3 * of the horizontal interval, this equation becomes slightly more complex: * - * l[i]^2 * h[i-1] + (3*(1-R[i-1])*l[i] + 3*(1-L[i+1])) * h[i] + 1/l[i+1] * h[i+1] = (y[i]-y[i-1])*l[i]^2 + y[i+1]-y[i] + * l[i]^2 * h[i-1] + (3*(1-R[i-1])*l[i] + 3*(1-L[i+1])) * h[i] + 1/l[i+1] * h[i+1] = dy[i]*l[i]^2 + dy[i+1] * * The difference between equations amounts to this, and it's obvious that when R[i-1] * and L[i+1] are both 1/3, it becomes zero: @@ -3699,6 +3708,14 @@ static bool tridiagonal_solve_with_limits(float *a, * * 4. The equations for zero acceleration border conditions are basically the above * equation with parts omitted, so the handle size correction also applies. + * + * 5. The fully cyclic curve case is handled by eliminating one of the end points, + * and instead of border conditions connecting the curve via a set of equations: + * + * l[0] = l[N] = dx[1] / dx[N] + * dy[0] = dy[N] + * Continuity equation (item 2) for i = 0. + * Substitute h[0] for h[N] and h[N-1] for h[-1] */ /* clang-format on */ @@ -3801,8 +3818,8 @@ static void bezier_output_handle(BezTriple *bezt, bool right, float dy, bool end static bool bezier_check_solve_end_handle(BezTriple *bezt, char htype, bool end) { - return (htype == HD_VECT) || - (end && ELEM(htype, HD_AUTO, HD_AUTO_ANIM) && bezt->f5 == HD_AUTOTYPE_NORMAL); + return (htype == HD_VECT) || (end && ELEM(htype, HD_AUTO, HD_AUTO_ANIM) && + bezt->auto_handle_type == HD_AUTOTYPE_NORMAL); } static float bezier_calc_handle_adj(float hsize[2], float dx) @@ -3995,7 +4012,7 @@ static void bezier_handle_calc_smooth_fcurve( static bool is_free_auto_point(BezTriple *bezt) { - return BEZT_IS_AUTOH(bezt) && bezt->f5 == HD_AUTOTYPE_NORMAL; + return BEZT_IS_AUTOH(bezt) && bezt->auto_handle_type == HD_AUTOTYPE_NORMAL; } void BKE_nurb_handle_smooth_fcurve(BezTriple *bezt, int total, bool cyclic) -- cgit v1.2.3