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Math Lib: add isect_seg_seg_v2_point_ex

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This exposes end-point bias argument, needed in rare cases.
This commit is contained in:
Campbell Barton
2017-08-12 18:12:29 +10:00
parent b5cd89bab9
commit 091ae0ea71
2 changed files with 38 additions and 12 deletions
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10
source/blender/blenlib/BLI_math_geom.h
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@@ -166,8 +166,14 @@ void limit_dist_v3(float v1[3], float v2[3], const float dist);
int isect_seg_seg_v2(const float a1[2], const float a2[2], const float b1[2], const float b2[2]);
int isect_seg_seg_v2_int(const int a1[2], const int a2[2], const int b1[2], const int b2[2]);
int isect_seg_seg_v2_point(const float v0[2], const float v1[2], const float v2[2], const float v3[2], float vi[2]);
bool isect_seg_seg_v2_simple(const float v1[2], const float v2[2], const float v3[2], const float v4[2]);
int isect_seg_seg_v2_point_ex(
const float v0[2], const float v1[2], const float v2[2], const float v3[2], const float endpoint_bias,
float vi[2]);
int isect_seg_seg_v2_point(
const float v0[2], const float v1[2], const float v2[2], const float v3[2],
float vi[2]);
bool isect_seg_seg_v2_simple(
const float v1[2], const float v2[2], const float v3[2], const float v4[2]);
int isect_line_sphere_v3(const float l1[3], const float l2[3], const float sp[3], const float r, float r_p1[3], float r_p2[3]);
int isect_line_sphere_v2(const float l1[2], const float l2[2], const float sp[2], const float r, float r_p1[2], float r_p2[2]);

40
source/blender/blenlib/intern/math_geom.c
View File

@@ -765,18 +765,29 @@ int isect_seg_seg_v2(const float v1[2], const float v2[2], const float v3[2], co
return ISECT_LINE_LINE_NONE;
}
/* get intersection point of two 2D segments and return intersection type:
* -1: collinear
* 1: intersection
/**
* Get intersection point of two 2D segments.
*
* \param endpoint_bias: Bias to use when testing for end-point overlap.
* A positive value considers intersections that extend past the endpoints,
* negative values contract the endpoints.
* Note the bias is applied to a 0-1 factor, not scaled to the length of segments.
*
* \returns intersection type:
* - -1: collinear.
* - 1: intersection.
* - 0: no intersection.
*/
int isect_seg_seg_v2_point(
int isect_seg_seg_v2_point_ex(
const float v0[2], const float v1[2],
const float v2[2], const float v3[2],
const float endpoint_bias,
float r_vi[2])
{
float s10[2], s32[2], s30[2], d;
const float eps = 1e-6f;
const float eps_sq = eps * eps;
const float endpoint_min = -endpoint_bias;
const float endpoint_max = endpoint_bias + 1.0f;
sub_v2_v2v2(s10, v1, v0);
sub_v2_v2v2(s32, v3, v2);
@@ -790,8 +801,8 @@ int isect_seg_seg_v2_point(
u = cross_v2v2(s30, s32) / d;
v = cross_v2v2(s10, s30) / d;
if ((u >= -eps && u <= 1.0f + eps) &&
(v >= -eps && v <= 1.0f + eps))
if ((u >= endpoint_min && u <= endpoint_max) &&
(v >= endpoint_min && v <= endpoint_max))
{
/* intersection */
float vi_test[2];
@@ -810,7 +821,7 @@ int isect_seg_seg_v2_point(
sub_v2_v2v2(s_vi_v2, vi_test, v2);
v = (dot_v2v2(s32, s_vi_v2) / dot_v2v2(s32, s32));
#endif
if (v >= -eps && v <= 1.0f + eps) {
if (v >= endpoint_min && v <= endpoint_max) {
copy_v2_v2(r_vi, vi_test);
return 1;
}
@@ -828,7 +839,7 @@ int isect_seg_seg_v2_point(
float u_a, u_b;
if (equals_v2v2(v0, v1)) {
if (len_squared_v2v2(v2, v3) > eps_sq) {
if (len_squared_v2v2(v2, v3) > SQUARE(eps)) {
/* use non-point segment as basis */
SWAP(const float *, v0, v2);
SWAP(const float *, v1, v3);
@@ -855,7 +866,7 @@ int isect_seg_seg_v2_point(
if (u_a > u_b)
SWAP(float, u_a, u_b);
if (u_a > 1.0f + eps || u_b < -eps) {
if (u_a > endpoint_max || u_b < endpoint_min) {
/* non-overlapping segments */
return -1;
}
@@ -871,6 +882,15 @@ int isect_seg_seg_v2_point(
}
}
int isect_seg_seg_v2_point(
const float v0[2], const float v1[2],
const float v2[2], const float v3[2],
float r_vi[2])
{
const float endpoint_bias = 1e-6f;
return isect_seg_seg_v2_point_ex(v0, v1, v2, v3, endpoint_bias, r_vi);
}
bool isect_seg_seg_v2_simple(const float v1[2], const float v2[2], const float v3[2], const float v4[2])
{
#define CCW(A, B, C) \