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Improve Vector3RotateByAxisAngle() function

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This commit is contained in:
Crydsch 2022-07-24 14:46:26 +02:00
parent 5d4eb778c4
commit 3e8f7162df
1 changed files with 53 additions and 7 deletions
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60
src/rcamera.h
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@ -202,9 +202,55 @@ Matrix GetCameraProjectionMatrix(Camera3D* camera, float aspect);
// Rotates the given vector around the given axis
// Note: angle must be provided in radians
Vector3 Vector3RotateAxis(Vector3 v, Vector3 axis, float angle) { // TODO there is a better way without the intermediate matrix
Matrix rot = MatrixRotate(axis, angle);
return Vector3Transform(v, rot);
Vector3 Vector3RotateByAxisAngle(Vector3 v, Vector3 axis, float angle)
{
// Using Euler-Rodrigues Formula
// Ref.: https://en.wikipedia.org/w/index.php?title=Euler%E2%80%93Rodrigues_formula
Vector3 result = v;
// Vector3Normalize(axis);
float length = sqrtf(axis.x * axis.x + axis.y * axis.y + axis.z * axis.z);
if (length == 0.0f) length = 1.0f;
float ilength = 1.0f / length;
axis.x *= ilength;
axis.y *= ilength;
axis.z *= ilength;
angle /= 2.0f;
float a = sinf(angle);
float b = axis.x * a;
float c = axis.y * a;
float d = axis.z * a;
a = cosf(angle);
Vector3 w = { b, c, d };
// Vector3CrossProduct(w, v)
Vector3 wv = { w.y * v.z - w.z * v.y, w.z * v.x - w.x * v.z, w.x * v.y - w.y * v.x };
// Vector3CrossProduct(w, wv)
Vector3 wwv = { w.y * wv.z - w.z * wv.y, w.z * wv.x - w.x * wv.z, w.x * wv.y - w.y * wv.x };
// Vector3Scale(wv, 2 * a)
a *= 2;
wv.x *= a;
wv.y *= a;
wv.z *= a;
// Vector3Scale(wwv, 2)
wwv.x *= 2;
wwv.y *= 2;
wwv.z *= 2;
result.x += wv.x;
result.y += wv.y;
result.z += wv.z;
result.x += wwv.x;
result.y += wwv.y;
result.z += wwv.z;
return result;
}
//----------------------------------------------------------------------------------
@ -340,7 +386,7 @@ void CameraYaw(Camera3D *camera, float angle)
Vector3 target_position = Vector3Subtract(camera->target, camera->position);
// Rotate view vector around up axis
target_position = Vector3RotateAxis(target_position, up, angle);
target_position = Vector3RotateByAxisAngle(target_position, up, angle);
if (camera->mode == CAMERA_FREE ||
camera->mode == CAMERA_FIRST_PERSON)
@ -390,7 +436,7 @@ void CameraPitch(Camera3D *camera, float angle)
Vector3 right = GetCameraRight(camera);
// Rotate view vector around right axis
target_position = Vector3RotateAxis(target_position, right, angle);
target_position = Vector3RotateByAxisAngle(target_position, right, angle);
if (camera->mode == CAMERA_FREE)
{
@ -398,7 +444,7 @@ void CameraPitch(Camera3D *camera, float angle)
camera->target = Vector3Add(camera->position, target_position);
// Rotate up direction around right axis
camera->up = Vector3RotateAxis(camera->up, right, angle);
camera->up = Vector3RotateByAxisAngle(camera->up, right, angle);
}
else if (camera->mode == CAMERA_FIRST_PERSON)
{
@ -422,7 +468,7 @@ void CameraRoll(Camera3D *camera, float angle)
Vector3 forward = GetCameraForward(camera);
// Rotate up direction around forward axis
camera->up = Vector3RotateAxis(camera->up, forward, angle);
camera->up = Vector3RotateByAxisAngle(camera->up, forward, angle);
}
// Moves camera slightly to simulate a walking motion