+/*
+gph-cmath - C graphics math library
+Copyright (C) 2018 John Tsiombikas <nuclear@member.fsf.org>
+
+This program is free software. Feel free to use, modify, and/or redistribute
+it under the terms of the MIT/X11 license. See LICENSE for details.
+If you intend to redistribute parts of the code without the LICENSE file
+replace this paragraph with the full contents of the LICENSE file.
+*/
static inline void cgm_mcopy(float *dest, const float *src)
{
memcpy(dest, src, 16 * sizeof(float));
subi = 0;
for(i=0; i<4; i++) {
- if(i == col) continue;
+ if(i == row) continue;
subj = 0;
for(j=0; j<4; j++) {
- if(j == row) continue;
+ if(j == col) continue;
m[subi * 4 + subj++] = orig[i * 4 + j];
}
m[15] = 1.0f;
}
-static inline float cgm_msubdet(float *m, int row, int col)
+static inline float cgm_msubdet(const float *m, int row, int col)
{
- cgm_msubmatrix(m, row, col);
- return cgm_mdet(m);
+ float tmp[16];
+ float subdet00, subdet01, subdet02;
+
+ cgm_mcopy(tmp, m);
+ cgm_msubmatrix(tmp, row, col);
+
+ subdet00 = tmp[5] * tmp[10] - tmp[6] * tmp[9];
+ subdet01 = tmp[4] * tmp[10] - tmp[6] * tmp[8];
+ subdet02 = tmp[4] * tmp[9] - tmp[5] * tmp[8];
+
+ return tmp[0] * subdet00 - tmp[1] * subdet01 + tmp[2] * subdet02;
}
-static inline float cgm_mcofactor(float *m, int row, int col)
+static inline float cgm_mcofactor(const float *m, int row, int col)
{
float min = cgm_msubdet(m, row, col);
return (row + col) & 1 ? -min : min;
}
-static inline float cgm_mdet(float *m)
+static inline float cgm_mdet(const float *m)
{
return m[0] * cgm_msubdet(m, 0, 0) - m[1] * cgm_msubdet(m, 0, 1) +
m[2] * cgm_msubdet(m, 0, 2) - m[3] * cgm_msubdet(m, 0, 3);
m[i * 4 + j] = cgm_mcofactor(tmp, j, i) * inv_det; /* transposed */
}
}
+ return 0;
}
static inline void cgm_mtranslation(float *m, float x, float y, float z)
cgm_mrotation_euler(m, a, b, c, mode);
cgm_mmul(m, tmp);
}
+
+
+static inline void cgm_mget_translation(const float *m, cgm_vec3 *res)
+{
+ res->x = m[12];
+ res->y = m[13];
+ res->z = m[14];
+}
+
+/* Algorithm in Ken Shoemake's article in 1987 SIGGRAPH course notes
+ * article "Quaternion Calculus and Fast Animation".
+ * adapted from: http://www.geometrictools.com/LibMathematics/Algebra/Wm5Quaternion.inl
+ */
+static inline void cgm_mget_rotation(const float *m, cgm_quat *res)
+{
+ static const int next[3] = {1, 2, 0};
+ float quat[4];
+ int i, j, k;
+
+ float trace = m[0] + m[5] + m[10];
+ float root;
+
+ if(trace > 0.0f) {
+ // |w| > 1/2
+ root = sqrt(trace + 1.0f); // 2w
+ res->w = 0.5f * root;
+ root = 0.5f / root; // 1 / 4w
+ res->x = (m[6] - m[9]) * root;
+ res->y = (m[8] - m[2]) * root;
+ res->z = (m[1] - m[4]) * root;
+ } else {
+ // |w| <= 1/2
+ i = 0;
+ if(m[5] > m[0]) {
+ i = 1;
+ }
+ if(m[10] > m[i * 4 + i]) {
+ i = 2;
+ }
+ j = next[i];
+ k = next[j];
+
+ root = sqrt(m[i * 4 + i] - m[j * 4 + j] - m[k * 4 + k] + 1.0f);
+ quat[i + 1] = 0.5f * root;
+ root = 0.5f / root;
+ quat[0] = (m[j + 4 + k] - m[k * 4 + j]) * root;
+ quat[j + 1] = (m[i * 4 + j] - m[j * 4 + i]) * root;
+ quat[k + 1] = (m[i * 4 + k] - m[k * 4 + i]) * root;
+ res->w = quat[0];
+ res->x = quat[1];
+ res->y = quat[2];
+ res->z = quat[3];
+ }
+}
+
+static inline void cgm_mget_scaling(const float *m, cgm_vec3 *res)
+{
+ res->x = sqrt(m[0] * m[0] + m[4] * m[4] + m[8] * m[8]);
+ res->y = sqrt(m[1] * m[1] + m[5] * m[5] + m[9] * m[9]);
+ res->z = sqrt(m[2] * m[2] + m[6] * m[6] + m[10] * m[10]);
+}
+
+static inline void cgm_mget_frustum_plane(const float *m, int p, cgm_vec4 *res)
+{
+ int row = p >> 1;
+ const float *rowptr = m + row * 4;
+
+ if((p & 1) == 0) {
+ res->x = m[12] + rowptr[0];
+ res->y = m[13] + rowptr[1];
+ res->z = m[14] + rowptr[2];
+ res->w = m[15] + rowptr[3];
+ } else {
+ res->x = m[12] - rowptr[0];
+ res->y = m[13] - rowptr[1];
+ res->z = m[14] - rowptr[2];
+ res->w = m[15] - rowptr[3];
+ }
+}
+
+static inline void cgm_mlookat(float *m, const cgm_vec3 *pos, const cgm_vec3 *targ,
+ const cgm_vec3 *up)
+{
+ float trans[16];
+ cgm_vec3 dir = *targ, right, vup;
+
+ cgm_vsub(&dir, pos);
+ cgm_vnormalize(&dir);
+ cgm_vcross(&right, &dir, up);
+ cgm_vnormalize(&right);
+ cgm_vcross(&vup, &right, &dir);
+ cgm_vnormalize(&vup);
+
+ cgm_midentity(m);
+ m[0] = right.x;
+ m[1] = right.y;
+ m[2] = right.z;
+ m[4] = vup.x;
+ m[5] = vup.y;
+ m[6] = vup.z;
+ m[8] = -dir.x;
+ m[9] = -dir.y;
+ m[10] = -dir.z;
+
+ cgm_mtranslation(trans, pos->x, pos->y, pos->z);
+ cgm_mmul(m, trans);
+}
+
+static inline void cgm_minv_lookat(float *m, const cgm_vec3 *pos, const cgm_vec3 *targ,
+ const cgm_vec3 *up)
+{
+ float rot[16];
+ cgm_vec3 dir = *targ, right, vup;
+
+ cgm_vsub(&dir, pos);
+ cgm_vnormalize(&dir);
+ cgm_vcross(&right, &dir, up);
+ cgm_vnormalize(&right);
+ cgm_vcross(&vup, &right, &dir);
+ cgm_vnormalize(&vup);
+
+ cgm_midentity(rot);
+ rot[0] = right.x;
+ rot[4] = right.y;
+ rot[8] = right.z;
+ rot[1] = vup.x;
+ rot[5] = vup.y;
+ rot[9] = vup.z;
+ rot[2] = -dir.x;
+ rot[6] = -dir.y;
+ rot[10] = -dir.z;
+
+ cgm_mtranslation(m, -pos->x, -pos->y, -pos->z);
+ cgm_mmul(m, rot);
+}
+
+static inline void cgm_mortho(float *m, float left, float right, float bot, float top,
+ float znear, float zfar)
+{
+ float dx = right - left;
+ float dy = top - bot;
+ float dz = zfar - znear;
+
+ cgm_midentity(m);
+ m[0] = 2.0f / dx;
+ m[5] = 2.0f / dy;
+ m[10] = -2.0f / dz;
+ m[12] = -(right + left) / dx;
+ m[13] = -(top + bot) / dy;
+ m[14] = -(zfar + znear) / dz;
+}
+
+static inline void cgm_mfrustum(float *m, float left, float right, float bot, float top,
+ float znear, float zfar)
+{
+ float dx = right - left;
+ float dy = top - bot;
+ float dz = zfar - znear;
+
+ cgm_mzero(m);
+ m[0] = 2.0f * znear / dx;
+ m[5] = 2.0f * znear / dy;
+ m[8] = (right + left) / dx;
+ m[9] = (top + bot) / dy;
+ m[10] = -(zfar + znear) / dz;
+ m[14] = -2.0f * zfar * znear / dz;
+ m[11] = -1.0f;
+}
+
+static inline void cgm_mperspective(float *m, float vfov, float aspect, float znear, float zfar)
+{
+ float s = 1.0f / (float)tan(vfov / 2.0f);
+ float range = znear - zfar;
+
+ cgm_mzero(m);
+ m[0] = s / aspect;
+ m[5] = s;
+ m[10] = (znear + zfar) / range;
+ m[14] = 2.0f * znear * zfar / range;
+ m[11] = -1.0f;
+}
+
+static inline void cgm_mmirror(float *m, float a, float b, float c, float d)
+{
+ m[0] = 1.0f - 2.0f * a * a;
+ m[5] = 1.0f - 2.0f * b * b;
+ m[10] = 1.0f - 2.0f * c * c;
+ m[15] = 1.0f;
+
+ m[1] = m[4] = -2.0f * a * b;
+ m[2] = m[8] = -2.0f * a * c;
+ m[6] = m[9] = -2.0f * b * c;
+
+ m[12] = -2.0f * a * d;
+ m[13] = -2.0f * b * d;
+ m[14] = -2.0f * c * d;
+
+ m[3] = m[7] = m[11] = 0.0f;
+}