3D Affine Transforms (common)

Common transfrom functions.

Table of contents (click to go):

Functions:

1. glm_translate_make()

2. glm_scale_to()

3. glm_scale_make()

4. glm_scale()

5. glm_scale_uni()

6. glm_rotate_make()

7. glm_rotate_atm()

8. glm_decompose_scalev()

9. glm_uniscaled()

10. glm_decompose_rs()

11. glm_decompose()

Functions documentation

void glm_translate_make(mat4 m, vec3 v)

creates NEW translate transform matrix by v vector.

Parameters:

[in, out] m affine transfrom

[in] v translate vector [x, y, z]

void glm_scale_to(mat4 m, vec3 v, mat4 dest)

scale existing transform matrix by v vector and store result in dest

Parameters:

[in] m affine transfrom

[in] v scale vector [x, y, z]

[out] dest scaled matrix

void glm_scale_make(mat4 m, vec3 v)

creates NEW scale matrix by v vector

Parameters:

[out] m affine transfrom

[in] v scale vector [x, y, z]

void glm_scale(mat4 m, vec3 v)

scales existing transform matrix by v vector and stores result in same matrix

Parameters:

[in, out] m affine transfrom

[in] v scale vector [x, y, z]

void glm_scale_uni(mat4 m, float s)

applies uniform scale to existing transform matrix v = [s, s, s] and stores result in same matrix

Parameters:

[in, out] m affine transfrom

[in] v scale factor

void glm_rotate_make(mat4 m, float angle, vec3 axis)

creates NEW rotation matrix by angle and axis, axis will be normalized so you don’t need to normalize it

Parameters:

[out] m affine transfrom

[in] axis angle (radians)

[in] axis axis

void glm_rotate_atm(mat4 m, vec3 pivot, float angle, vec3 axis)

creates NEW rotation matrix by angle and axis at given point

this creates rotation matrix, it assumes you don’t have a matrix

this should work faster than glm_rotate_at because it reduces one glm_translate.

Parameters:

[in, out] m affine transfrom

[in] pivot pivot, anchor point, rotation center

[in] angle angle (radians)

[in] axis axis

void glm_decompose_scalev(mat4 m, vec3 s)

decompose scale vector

Parameters:

[in] m affine transform

[out] s scale vector (Sx, Sy, Sz)

bool glm_uniscaled(mat4 m)

returns true if matrix is uniform scaled. This is helpful for creating normal matrix.

Parameters:

[in] m matrix

void glm_decompose_rs(mat4 m, mat4 r, vec3 s)

decompose rotation matrix (mat4) and scale vector [Sx, Sy, Sz] DON’T pass projected matrix here

Parameters:

[in] m affine transform

[out] r rotation matrix

[out] s scale matrix

void glm_decompose(mat4 m, vec4 t, mat4 r, vec3 s)

decompose affine transform, TODO: extract shear factors. DON’T pass projected matrix here

Parameters:

[in] m affine transfrom

[out] t translation vector

[out] r rotation matrix (mat4)

[out] s scaling vector [X, Y, Z]