3d-renderer/scripts/matrix.c
2025-07-11 23:56:41 -07:00

103 lines
2.0 KiB
C

#include "matrix.h"
mat4_t mat4_identity(void) {
mat4_t m = {{
{ 1, 0, 0, 0},
{ 0, 1, 0, 0},
{ 0, 0, 1, 0},
{ 0, 0, 0, 1},
}};
return m;
}
mat4_t mat4_make_scale(float sx, float sy, float sz) {
mat4_t m = mat4_identity();
m.m[0][0] *= sx;
m.m[1][1] *= sy;
m.m[2][2] *= sz;
return m;
}
mat4_t mat4_make_translation(float tx, float ty, float tz) {
/*
* 1 0 0 tx
* 0 1 0 ty
* 0 0 1 tz
* 0 0 0 1
*/
mat4_t m = mat4_identity();
m.m[0][3] = tx;
m.m[1][3] = ty;
m.m[2][3] = tz;
return m;
}
mat4_t mat4_make_rotation_y(float ra) {
/*
* cos 0 -sin 0
* 0 1 0 0
* sin 0 cos 0
* 0 0 0 1
*/
const float cosine = cosf(ra);
const float sine = sinf(ra);
mat4_t m = mat4_identity();
m.m[0][0] = cosine;
m.m[0][2] = -sine;
m.m[2][0] = sine;
m.m[2][2] = cosine;
return m;
}
mat4_t mat4_make_rotation_x(float ra) {
/*
* 1 0 0 0
* 0 cos sin 0
* 0 -sin cos 0
* 0 0 0 1
*/
const float cosine = cosf(ra);
const float sine = sinf(ra);
mat4_t m = mat4_identity();
m.m[1][1] = cosine;
m.m[1][2] = sine;
m.m[2][1] = -sine;
m.m[2][2] = cosine;
return m;
}
mat4_t mat4_make_rotation_z(float ra) {
/*
* cos sin 0 0
* -sin cos 0 0
* 0 0 1 0
* 0 0 0 1
*/
const float cosine = cosf(ra);
const float sine = sinf(ra);
mat4_t m = mat4_identity();
m.m[0][0] = cosine;
m.m[0][1] = sine;
m.m[1][0] = -sine;
m.m[1][1] = cosine;
return m;
}
vec4_t mat4_multiply_vec4(mat4_t m, vec4_t v) {
vec4_t ret = {};
ret.x = m.m[0][0] * v.x + m.m[0][1] * v.y + m.m[0][2] * v.z + m.m[0][3] * v.w;
ret.y = m.m[1][0] * v.x + m.m[1][1] * v.y + m.m[1][2] * v.z + m.m[1][3] * v.w;
ret.z = m.m[2][0] * v.x + m.m[2][1] * v.y + m.m[2][2] * v.z + m.m[2][3] * v.w;
ret.w = m.m[3][0] * v.x + m.m[3][1] * v.y + m.m[3][2] * v.z + m.m[3][3] * v.w;
return ret;
}