DevKit7/citro3d
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Changed function declaration to match what was requested.

Browse Source
This commit is contained in:
Thompson Lee 2016-08-07 08:12:52 -04:00
parent 6eb0cacd0a
commit 2efedfe8d2
2 changed files with 21 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/c3d/maths.h
View File

@ -624,10 +624,10 @@ void Mtx_FromQuat(C3D_Mtx* m, C3D_FQuat q);
/**
* @brief Get Quaternion equivalent to 4x4 matrix
* @note If the matrix is orthogonal or special orthogonal, where determinant(matrix) = +1.0f, then the matrix can be converted.
* @param[out] q Output Quaternion
* @param[in] m Input Matrix
* @return Generated Quaternion
*/
void Quat_FromMtx(C3D_FQuat* q, C3D_Mtx m);
C3D_FQuat Quat_FromMtx(C3D_Mtx m);
/**
* @brief Identity Quaternion

36
source/maths/quat_frommtx.c
View File

@ -1,6 +1,6 @@
#include <c3d/maths.h>
void Quat_FromMtx(C3D_FQuat* q, C3D_Mtx m)
C3D_FQuat Quat_FromMtx(C3D_Mtx m)
{
//Taken from Gamasutra:
//http://www.gamasutra.com/view/feature/131686/rotating_objects_using_quaternions.php
@ -9,6 +9,7 @@ void Quat_FromMtx(C3D_FQuat* q, C3D_Mtx m)
//Variables we need.
float trace, sqrtTrace;
C3D_FQuat q;
//Check the main diagonal of the passed-in matrix for positive/negative signs.
trace = m.r[0].c[0] + m.r[1].c[1] + m.r[2].c[2];
@ -16,11 +17,11 @@ void Quat_FromMtx(C3D_FQuat* q, C3D_Mtx m)
{
//Diagonal is positive.
sqrtTrace = sqrtf(trace + 1.0f);
q->w = sqrtTrace / 2.0f;
q.w = sqrtTrace / 2.0f;
sqrtTrace = 0.5 / sqrtTrace;
q->x = (m.r[1].c[2] - m.r[2].c[1]) * sqrtTrace;
q->y = (m.r[2].c[0] - m.r[0].c[2]) * sqrtTrace;
q->z = (m.r[0].c[1] - m.r[1].c[0]) * sqrtTrace;
q.x = (m.r[1].c[2] - m.r[2].c[1]) * sqrtTrace;
q.y = (m.r[2].c[0] - m.r[0].c[2]) * sqrtTrace;
q.z = (m.r[0].c[1] - m.r[1].c[0]) * sqrtTrace;
}
else
{
@ -28,26 +29,27 @@ void Quat_FromMtx(C3D_FQuat* q, C3D_Mtx m)
if (m.r[0].c[0] > m.r[1].c[1] && m.r[0].c[0] > m.r[2].c[2])
{
sqrtTrace = 2.0f * sqrtf(1.0f + m.r[0].c[0] - m.r[1].c[1] - m.r[2].c[2]);
q->w = (m.r[2].c[1] - m.r[1].c[2]) / sqrtTrace;
q->x = 0.25f * sqrtTrace;
q->y = (m.r[0].c[1] - m.r[1].c[0]) / sqrtTrace;
q->z = (m.r[0].c[2] - m.r[2].c[0]) / sqrtTrace;
q.w = (m.r[2].c[1] - m.r[1].c[2]) / sqrtTrace;
q.x = 0.25f * sqrtTrace;
q.y = (m.r[0].c[1] - m.r[1].c[0]) / sqrtTrace;
q.z = (m.r[0].c[2] - m.r[2].c[0]) / sqrtTrace;
}
else if (m.r[1].c[1] > m.r[2].c[2])
{
sqrtTrace = 2.0f * sqrtf(1.0f + m.r[1].c[1] - m.r[0].c[0] - m.r[2].c[2]);
q->w = (m.r[0].c[2] - m.r[2].c[0]) / sqrtTrace;
q->x = (m.r[0].c[1] - m.r[1].c[0]) / sqrtTrace;
q->y = 0.25f * sqrtTrace;
q->z = (m.r[1].c[2] - m.r[2].c[1]) / sqrtTrace;
q.w = (m.r[0].c[2] - m.r[2].c[0]) / sqrtTrace;
q.x = (m.r[0].c[1] - m.r[1].c[0]) / sqrtTrace;
q.y = 0.25f * sqrtTrace;
q.z = (m.r[1].c[2] - m.r[2].c[1]) / sqrtTrace;
}
else
{
sqrtTrace = 2.0f * sqrtf(1.0f + m.r[2].c[2] - m.r[0].c[0] - m.r[1].c[1]);
q->w = (m.r[1].c[0] - m.r[0].c[1]) / sqrtTrace;
q->x = (m.r[0].c[2] - m.r[2].c[0]) / sqrtTrace;
q->y = (m.r[1].c[2] - m.r[2].c[1]) / sqrtTrace;
q->z = 0.25f * sqrtTrace;
q.w = (m.r[1].c[0] - m.r[0].c[1]) / sqrtTrace;
q.x = (m.r[0].c[2] - m.r[2].c[0]) / sqrtTrace;
q.y = (m.r[1].c[2] - m.r[2].c[1]) / sqrtTrace;
q.z = 0.25f * sqrtTrace;
}
}
return q;
}