0ce2c1398c
Removing excess copy/paste code. Please check my TAU... Fixed K&R. One-liner IFs. Changed bogus code to accept Quat_FromAxisAngle(vector, angle). Normalized axis vector in Quat_FromAxisAngle(). Missed that little cross. Replaced FVec4_New() with Quat_New(). * Changed bogus code to accept Quat_FromAxisAngle(vector, angle). Normalized axis vector in Quat_FromAxisAngle(). Missed that little cross. Replaced FVec4_New() with Quat_New().
16 lines
574 B
C
16 lines
574 B
C
#include <c3d/maths.h>
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#include <float.h>
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C3D_FQuat Quat_LookAt(C3D_FVec source, C3D_FVec target, C3D_FVec forwardVector, C3D_FVec upVector)
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{
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C3D_FVec forward = FVec3_Normalize(FVec3_Subtract(target, source));
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float dot = FVec3_Dot(forwardVector, forward);
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if (dot + 1.0f < FLT_EPSILON)
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return Quat_FromAxisAngle(upVector, M_TAU/2.0f);
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if (dot - 1.0f < -FLT_EPSILON)
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return Quat_Identity();
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float rotationAngle = acosf(dot);
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C3D_FVec rotationAxis = FVec3_Normalize(FVec3_Cross(forwardVector, forward));
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return Quat_FromAxisAngle(rotationAxis, rotationAngle);
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}
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