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Add DrawSplineSegmentLinearVar

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This commit is contained in:
Henry Wilder 2025-03-04 12:02:39 -05:00
commit 6f89aa57ab
2 changed files with 109 additions and 6 deletions
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1
src/raylib.h
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@ -1298,6 +1298,7 @@ RLAPI void DrawSplineSegmentBasis(Vector2 p1, Vector2 p2, Vector2 p3, Vector2 p4
RLAPI void DrawSplineSegmentCatmullRom(Vector2 p1, Vector2 p2, Vector2 p3, Vector2 p4, float thick, Color color); // Draw spline segment: Catmull-Rom, 4 points
RLAPI void DrawSplineSegmentBezierQuadratic(Vector2 p1, Vector2 c2, Vector2 p3, float thick, Color color); // Draw spline segment: Quadratic Bezier, 2 points, 1 control point
RLAPI void DrawSplineSegmentBezierCubic(Vector2 p1, Vector2 c2, Vector2 c3, Vector2 p4, float thick, Color color); // Draw spline segment: Cubic Bezier, 2 points, 2 control points
RLAPI void DrawSplineSegmentLinearVar(Vector2 p1, Vector2 p2, const float* thicks, int thickCount, Color color); // Draw spline segment with variable thickness: Linear Bezier, 2 points
RLAPI void DrawSplineSegmentBezierCubicVar(Vector2 p1, Vector2 c2, Vector2 c3, Vector2 p4, const float* thicks, int thickCount, Color color); // Draw spline segment with variable thickness: Cubic Bezier, 2 points, 2 control points
// Spline segment point evaluation functions, for a given t [0.0f .. 1.0f]

89
src/rshapes.c
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@ -2107,6 +2107,89 @@ void DrawSplineSegmentBezierCubic(Vector2 p1, Vector2 c2, Vector2 c3, Vector2 p4
DrawTriangleStrip(points, 2*SPLINE_SEGMENT_DIVISIONS + 2, color);
}
// Draw spline segment with variable thickness: Linear, 2 points
void DrawSplineSegmentLinearVar(Vector2 p1, Vector2 p2, const float* thicks, int thickCount, Color color)
{
if (thickCount >= 4)
{
const float step = 1.0f/SPLINE_SEGMENT_DIVISIONS;
Vector2 previous[2] = { 0 };
Vector2 current[2] = { 0 };
float t = 0.0f;
// Linear velocity does not change across the curve
Vector2 tangent = { 0 };
tangent.x = p2.x - p1.x;
tangent.y = p2.y - p1.y;
float speedSqr = tangent.x*tangent.x + tangent.y*tangent.y;
if (speedSqr > 0)
{
float speedInv = 1.0f/sqrtf(speedSqr);
tangent.x *= speedInv;
tangent.y *= speedInv;
rlBegin(RL_TRIANGLES);
rlColor4ub(color.r, color.g, color.b, color.a);
for (int i = 0; i <= SPLINE_SEGMENT_DIVISIONS; i++)
{
t = step*(float)i;
Vector2 point = { 0 };
point.x = p1.x*(1.0f - t) + p2.x*t;
point.y = p1.y*(1.0f - t) + p2.y*t;
// TODO: Doesn't seem to be working properly for more than 3 distinct values
float thick;
{
float tMajor = t*(float)thickCount;
int tIndex = (int)tMajor;
float tMinor = tMajor - (float)tIndex;
tIndex *= 3;
if (tIndex >= thickCount - 3)
{
tIndex = thickCount - 4;
tMinor = 1.0f;
}
float a = powf(1.0f - t, 3);
float b = 3.0f*powf(1.0f - t, 2)*t;
float c = 3.0f*(1.0f - t)*t*t;
float d = t*t*t;
thick = a*thicks[tIndex] + b*thicks[tIndex + 1] + c*thicks[tIndex + 2] + d*thicks[tIndex + 3];
}
current[0].x = point.x + thick*tangent.y;
current[0].y = point.y - thick*tangent.x;
current[1].x = point.x - thick*tangent.y;
current[1].y = point.y + thick*tangent.x;
if (i > 0)
{
rlVertex2f(current[0].x, current[0].y);
rlVertex2f(previous[0].x, previous[0].y);
rlVertex2f(previous[1].x, previous[1].y);
rlVertex2f(current[1].x, current[1].y);
rlVertex2f(current[0].x, current[0].y);
rlVertex2f(previous[1].x, previous[1].y);
}
previous[0] = current[0];
previous[1] = current[1];
}
rlEnd();
}
}
}
// Draw spline segment with variable thickness: Cubic Bezier, 2 points, 2 control points
void DrawSplineSegmentBezierCubicVar(Vector2 p1, Vector2 c2, Vector2 c3, Vector2 p4, const float* thicks, int thickCount, Color color)
{
@ -2138,8 +2221,8 @@ void DrawSplineSegmentBezierCubicVar(Vector2 p1, Vector2 c2, Vector2 c3, Vector2
float speedSqr = (tangent.x*tangent.x + tangent.y*tangent.y);
if (speedSqr == 0) continue;
float speedInv = 1.0f/sqrtf(speedSqr);
tangent.x = tangent.x*speedInv;
tangent.y = tangent.y*speedInv;
tangent.x *= speedInv;
tangent.y *= speedInv;
Vector2 point = { 0 };
{
@ -2178,7 +2261,7 @@ void DrawSplineSegmentBezierCubicVar(Vector2 p1, Vector2 c2, Vector2 c3, Vector2
current[1].x = point.x - thick*tangent.y;
current[1].y = point.y + thick*tangent.x;
if (i > 0)
if (i > 0) // TODO: `previous` may be unassigned in i=1 if i=0 had a `speedSqr` of 0
{
rlVertex2f(current[0].x, current[0].y);
rlVertex2f(previous[0].x, previous[0].y);