Reflect a vector in relation to another vector

Member

Posts: 96
Joined: 2011.07

Post: #1

Nov 22, 2011 — 11:37 AM

Hey,

I'm stuck with a geometrical problem. I have vector A and vector V. I need to find vector A' that is the reflection of A in relation to V (see pic).

[Image: reflect.jpg]

respect,
pk

iFrog is coming.

skyhawk

Moderator

Posts: 915
Joined: 2002.10

Post: #2

Nov 22, 2011 — 01:30 PM

in 2D or 3D space?

ipeku

Member

Posts: 96
Joined: 2011.07

Post: #3

Nov 22, 2011 — 01:35 PM

2D space.

respect,
pk

iFrog is coming.

ThemsAllTook

Moderator

Posts: 1,552
Joined: 2003.10

Post: #4

Nov 22, 2011 — 02:03 PM

This one's pretty simple:

Code:

float Vector2_dot(Vector2 vector1, Vector2 vector2) {

    return vector1.x * vector2.x + vector1.y * vector2.y;

}

Vector2 Vector2_reflect(Vector2 vector, Vector2 normal) {

    Vector2 result;

    float dot;

    dot = Vector2_dot(vector, normal);

    result.x = 2 * dot * normal.x - vector.x;

    result.y = 2 * dot * normal.y - vector.y;

    return result;

}

ipeku

Member

Posts: 96
Joined: 2011.07

Post: #5

Dec 12, 2011 — 07:17 AM

Awesome. Just trying it out (too many side quests).

...

Hey it's working !!! Thanks.

[Image: l.jpg]

respect,
pk

iFrog is coming.

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