limit bisectrice length in strokes, prevent oversized line joins, may be more accurate

diff --git a/src/vectors.c b/src/vectors.c
index 14d045b49ca2d815ca7e1222c4b68993575a52ac..812d19792f3c2dae2f82b7fa738c0a4d2c160009 100644 (file)
--- a/src/vectors.c
+++ b/src/vectors.c
@@ -62,11 +62,18 @@ vec2d vec2d_norm(vec2d a)
 }
 // multiply 2d vector by scalar
 vec2d vec2d_mult(vec2d a, double m){
-       return (vec2d){a.x*m,a.y*m};
+    return (vec2d){a.x*m,a.y*m};
+}
+// devide 2d vector by scalar
+vec2 vec2_div(vec2 a, float m){
+    return (vec2){a.x/m,a.y/m};
+}
+vec2d vec2d_div(vec2d a, double m){
+    return (vec2d){a.x/m,a.y/m};
 }
 // multiply 2d vector by scalar
 vec2 vec2_mult(vec2 a, float m){
-       return (vec2){a.x*m,a.y*m};
+    return (vec2){a.x*m,a.y*m};
 }
 // compute perpendicular vector
 vec2d vec2d_perp (vec2d a){

diff --git a/src/vectors.h b/src/vectors.h
index 3cf2500c15e79a60c76617516b149a2d3cd2acc4..c639bd59d8d86c004fe98e52bca9b2fd7254b180 100644 (file)
--- a/src/vectors.h
+++ b/src/vectors.h
@@ -78,6 +78,7 @@ vec2          vec2_perp       (vec2 a);
 vec2           vec2_add        (vec2 a, vec2 b);
 vec2           vec2_sub        (vec2 a, vec2 b);
 vec2           vec2_mult       (vec2 a, float m);
+vec2           vec2_div        (vec2 a, float m);
 bool           vec2_equ        (vec2 a, vec2 b);
 vec2           vec2_line_norm  (vec2 a, vec2 b);
 bool        vec2_isnan  (vec2 v);
@@ -88,6 +89,7 @@ vec2d         vec2d_perp      (vec2d a);
 vec2d          vec2d_add       (vec2d a, vec2d b);
 vec2d          vec2d_sub       (vec2d a, vec2d b);
 vec2d          vec2d_mult      (vec2d a, double m);
+vec2d          vec2d_div       (vec2d a, double m);
 vec2d          vec2d_line_norm(vec2d a, vec2d b);
 bool        vec2d_isnan  (vec2d v);
 

diff --git a/src/vkvg_context_internal.c b/src/vkvg_context_internal.c
index e2c0171f12038eb711607956ca41db7c1c6d5659..4793d7ad4fa305ac7c015f713335710237a2e34d 100644 (file)
--- a/src/vkvg_context_internal.c
+++ b/src/vkvg_context_internal.c
@@ -732,13 +732,14 @@ void _init_descriptor_sets (VkvgContext ctx){
 float _build_vb_step (vkvg_context* ctx, float hw, vec2 pL, vec2 p0, vec2 pR, bool isCurve){
        Vertex v = {{0},ctx->curColor, {0,0,-1}};
 
-       //if two of the three points are equal, normal is null
-       vec2 v0n = vec2_line_norm(pL, p0);
-       if (vec2_isnan(v0n))
-               return 0;
-       vec2 v1n = vec2_line_norm(p0, pR);
-       if (vec2_isnan(v1n))
-               return 0;
+    vec2 v0 = vec2_sub(p0, pL);
+    vec2 v1 = vec2_sub(pR, p0);
+    float length_v0 = vec2_length(v0);
+    float length_v1 = vec2_length(v1);
+    if (length_v0 < FLT_EPSILON || length_v1 < FLT_EPSILON)
+        return 0;
+    vec2 v0n = vec2_div (v0, length_v0);
+    vec2 v1n = vec2_div (v1, length_v1);
 
        vec2 bisec = vec2_norm(vec2_add(v0n,v1n));
 
@@ -751,6 +752,10 @@ float _build_vb_step (vkvg_context* ctx, float hw, vec2 pL, vec2 p0, vec2 pR, bo
 
        float lh = hw / cosf(alpha);
        bisec = vec2_perp(bisec);
+
+    //limit bisectrice lenght, may be improved but ok for perf
+    lh=fminf (lh, fminf (sqrtf(length_v0*length_v0+hw*hw), sqrtf(length_v1*length_v1+hw*hw)));
+
        bisec = vec2_mult(bisec,lh);
 
        VKVG_IBO_INDEX_TYPE idx = (VKVG_IBO_INDEX_TYPE)(ctx->vertCount - ctx->curVertOffset);
@@ -758,9 +763,9 @@ float _build_vb_step (vkvg_context* ctx, float hw, vec2 pL, vec2 p0, vec2 pR, bo
        if (ctx->lineJoin == VKVG_LINE_JOIN_MITER || isCurve){
                v.pos = vec2_add(p0, bisec);
                _add_vertex(ctx, v);
-               v.pos = vec2_sub(p0, bisec);
-               _add_vertex(ctx, v);
-               _add_tri_indices_for_rect(ctx, idx);
+        v.pos = vec2_sub(p0, bisec);
+        _add_vertex(ctx, v);
+        _add_tri_indices_for_rect(ctx, idx);
        }else{
                vec2 vp = vec2_perp(v0n);
                if (cross<0){
@@ -771,7 +776,7 @@ float _build_vb_step (vkvg_context* ctx, float hw, vec2 pL, vec2 p0, vec2 pR, bo
                        v.pos = vec2_add (p0, vec2_mult (vp, hw));
                        _add_vertex(ctx, v);
                        v.pos = vec2_sub (p0, bisec);
-               }
+        }
                _add_vertex(ctx, v);
 
                if (ctx->lineJoin == VKVG_LINE_JOIN_BEVEL){