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convert quaterinon to xyzw order (part 1)

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Recep Aslantas
2018-04-09 18:49:12 +03:00
parent 7615f785ac
commit 3dc93c56e8
6 changed files with 112 additions and 118 deletions
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52
include/cglm/mat3.h
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@@ -198,39 +198,41 @@ void
glm_mat3_quat(mat3 m, versor dest) {
float trace, r, rinv;
/* it seems using like m12 instead of m[1][2] causes extra instructions */
trace = m[0][0] + m[1][1] + m[2][2];
if (trace >= 0.0f) {
r = 2.0f * sqrtf(1 + trace);
rinv = 1.0f / r;
r = sqrtf(1.0f + trace);
rinv = 0.5f / r;
dest[1] = rinv * (m[1][2] - m[2][1]);
dest[2] = rinv * (m[2][0] - m[0][2]);
dest[3] = rinv * (m[0][1] - m[1][0]);
dest[0] = r * 0.25f;
} else if (m[0][0] >= m[1][1] && m[0][0] >= m[2][2]) {
r = 2.0f * sqrtf(1 - m[1][1] - m[2][2] + m[0][0]);
rinv = 1.0f / r;
dest[1] = r * 0.25f;
dest[2] = rinv * (m[0][1] + m[1][0]);
dest[3] = rinv * (m[0][2] + m[2][0]);
dest[0] = rinv * (m[1][2] - m[2][1]);
} else if (m[1][1] >= m[2][2]) {
r = 2.0f * sqrtf(1 - m[0][0] - m[2][2] + m[1][1]);
rinv = 1.0f / r;
dest[1] = rinv * (m[2][0] - m[0][2]);
dest[2] = rinv * (m[0][1] - m[1][0]);
dest[3] = r * 0.5f;
} else if (m[0][0] >= m[1][1] && m[0][0] >= m[2][2]) {
r = sqrtf(1.0f - m[1][1] - m[2][2] + m[0][0]);
rinv = 0.5f / r;
dest[0] = r * 0.5f;
dest[1] = rinv * (m[0][1] + m[1][0]);
dest[2] = r * 0.25f;
dest[3] = rinv * (m[1][2] + m[2][1]);
dest[0] = rinv * (m[2][0] - m[0][2]);
} else {
r = 2.0f * sqrtf(1 - m[0][0] - m[1][1] + m[2][2]);
rinv = 1.0f / r;
dest[2] = rinv * (m[0][2] + m[2][0]);
dest[3] = rinv * (m[1][2] - m[2][1]);
} else if (m[1][1] >= m[2][2]) {
r = sqrtf(1.0f - m[0][0] - m[2][2] + m[1][1]);
rinv = 0.5f / r;
dest[1] = rinv * (m[0][2] + m[2][0]);
dest[0] = rinv * (m[0][1] + m[1][0]);
dest[1] = r * 0.5f;
dest[2] = rinv * (m[1][2] + m[2][1]);
dest[3] = r * 0.25f;
dest[0] = rinv * (m[0][1] - m[1][0]);
dest[3] = rinv * (m[2][0] - m[0][2]);
} else {
r = sqrtf(1.0f - m[0][0] - m[1][1] + m[2][2]);
rinv = 0.5f / r;
dest[0] = rinv * (m[0][2] + m[2][0]);
dest[1] = rinv * (m[1][2] + m[2][1]);
dest[2] = r * 0.5f;
dest[3] = rinv * (m[0][1] - m[1][0]);
}
}