tight angle curve, switch to curved join when angle above const limit

diff --git a/src/vkvg_context_internal.c b/src/vkvg_context_internal.c
index 017e46d19f622ec934b608c75c78301e0512dfb4..415037a3aae6d8631c20676a1e65f890f4bd880a 100644 (file)
--- a/src/vkvg_context_internal.c
+++ b/src/vkvg_context_internal.c
@@ -942,7 +942,7 @@ bool _build_vb_step (vkvg_context* ctx, float hw, stroke_context_t* str, bool is
        vec2 bisec_n_perp = vec2_perp(bisec_n);
 
        //limit bisectrice length
-       float rlh = lh;
+       float rlh = lh;//rlh is for inside pos tweeks
        if (dot < 0.f)
                rlh = fminf (rlh, fminf (length_v0, length_v1));
        //---
@@ -978,8 +978,16 @@ bool _build_vb_step (vkvg_context* ctx, float hw, stroke_context_t* str, bool is
                }
        }
 
+       vkvg_line_join_t join = ctx->lineJoin;
 
-       if (ctx->lineJoin == VKVG_LINE_JOIN_MITER || isCurve){
+       if (isCurve) {
+               if (dot < 0.8f)
+                       join = VKVG_LINE_JOIN_ROUND;
+               else
+                       join = VKVG_LINE_JOIN_MITER;
+       }
+
+       if (join == VKVG_LINE_JOIN_MITER){
                if (lh > str->lhMax) {//miter limit
                        double x = (lh - str->lhMax) * cosf (halfAlpha);
                        vec2 bisecPerp = vec2_mult_s (bisec_n, x);
@@ -1052,7 +1060,7 @@ bool _build_vb_step (vkvg_context* ctx, float hw, stroke_context_t* str, bool is
                }
                _add_vertex(ctx, v);
 
-               if (ctx->lineJoin == VKVG_LINE_JOIN_BEVEL){
+               if (join == VKVG_LINE_JOIN_BEVEL){
                        if (det<0){
                                _add_triangle_indices(ctx, idx, idx+2, idx+1);
                                _add_triangle_indices(ctx, idx+2, idx+4, idx+0);
@@ -1062,7 +1070,7 @@ bool _build_vb_step (vkvg_context* ctx, float hw, stroke_context_t* str, bool is
                                _add_triangle_indices(ctx, idx+2, idx+3, idx+1);
                                _add_triangle_indices(ctx, idx+1, idx+3, idx+4);
                        }
-               }else if (ctx->lineJoin == VKVG_LINE_JOIN_ROUND){
+               }else if (join == VKVG_LINE_JOIN_ROUND){
                        float step = M_PIF / hw;
                        float a = acosf(vp.x);
                        if (vp.y < 0)