133 lines
3.4 KiB
C
133 lines
3.4 KiB
C
#include "vec.h"
|
|
|
|
#define DEPTH_MAX 255
|
|
|
|
M4x4f lookat(V3f eye, V3f target, V3f up) {
|
|
V3f z = V3(V3f, f32, target.x, target.y, target.z, eye.x, eye.y, eye.z);
|
|
normalise_v3(z);
|
|
V3f x = cross_product(up, z);
|
|
normalise_v3(x);
|
|
V3f y = cross_product(z, x);
|
|
normalise_v3(y);
|
|
|
|
M4x4f rotation = mat4x4_identity;
|
|
rotation.row0.x = x.x;
|
|
rotation.row0.y = x.y;
|
|
rotation.row0.z = x.z;
|
|
rotation.row1.x = y.x;
|
|
rotation.row1.y = y.y;
|
|
rotation.row1.z = y.z;
|
|
rotation.row2.x = z.x;
|
|
rotation.row2.y = z.y;
|
|
rotation.row2.z = z.z;
|
|
|
|
M4x4f translation = mat4x4_identity;
|
|
translation.row0.w = -(eye.x);
|
|
translation.row1.w = -(eye.y);
|
|
translation.row2.w = -(eye.z);
|
|
|
|
return mat4x4_mul(rotation, translation);
|
|
}
|
|
|
|
M4x4f projection(f32 coeff) {
|
|
// clang-format off
|
|
return (M4x4f){
|
|
.row0 = {1.0f, 0.0f, 0.0f, 0.0f},
|
|
.row1 = {0.0f, 1.0f, 0.0f, 0.0f},
|
|
.row2 = {0.0f, 0.0f, 1.0f, 0.0f},
|
|
.row3 = {0.0f, 0.0f, coeff, 1.0f},
|
|
};
|
|
// clang-format on
|
|
}
|
|
|
|
M4x4f viewport(f32 x, f32 y, u64 w, u64 h) {
|
|
M4x4f output = mat4x4_identity;
|
|
|
|
f32 half_width = (f32)w * 0.5f;
|
|
f32 half_height = (f32)h * 0.5f;
|
|
f32 half_depth = (f32)DEPTH_MAX * 0.5f;
|
|
|
|
output.row0.x = half_width;
|
|
output.row0.w = x + half_width;
|
|
output.row1.y = half_height;
|
|
output.row1.w = y + half_height;
|
|
output.row2.z = output.row2.w = half_depth;
|
|
|
|
return output;
|
|
}
|
|
|
|
M4x4f mat4x4_inv(M4x4f matrix) {
|
|
f32 mat[4][4] = mat4x4_to_array(matrix);
|
|
f32 dest[4][4] = {0};
|
|
|
|
f32 t[6];
|
|
f32 det;
|
|
f32 a = mat[0][0], b = mat[0][1], c = mat[0][2], d = mat[0][3], e = mat[1][0],
|
|
f = mat[1][1], g = mat[1][2], h = mat[1][3], i = mat[2][0], j = mat[2][1],
|
|
k = mat[2][2], l = mat[2][3], m = mat[3][0], n = mat[3][1], o = mat[3][2],
|
|
p = mat[3][3];
|
|
|
|
t[0] = k * p - o * l;
|
|
t[1] = j * p - n * l;
|
|
t[2] = j * o - n * k;
|
|
t[3] = i * p - m * l;
|
|
t[4] = i * o - m * k;
|
|
t[5] = i * n - m * j;
|
|
|
|
dest[0][0] = f * t[0] - g * t[1] + h * t[2];
|
|
dest[1][0] = -(e * t[0] - g * t[3] + h * t[4]);
|
|
dest[2][0] = e * t[1] - f * t[3] + h * t[5];
|
|
dest[3][0] = -(e * t[2] - f * t[4] + g * t[5]);
|
|
|
|
dest[0][1] = -(b * t[0] - c * t[1] + d * t[2]);
|
|
dest[1][1] = a * t[0] - c * t[3] + d * t[4];
|
|
dest[2][1] = -(a * t[1] - b * t[3] + d * t[5]);
|
|
dest[3][1] = a * t[2] - b * t[4] + c * t[5];
|
|
|
|
t[0] = g * p - o * h;
|
|
t[1] = f * p - n * h;
|
|
t[2] = f * o - n * g;
|
|
t[3] = e * p - m * h;
|
|
t[4] = e * o - m * g;
|
|
t[5] = e * n - m * f;
|
|
|
|
dest[0][2] = b * t[0] - c * t[1] + d * t[2];
|
|
dest[1][2] = -(a * t[0] - c * t[3] + d * t[4]);
|
|
dest[2][2] = a * t[1] - b * t[3] + d * t[5];
|
|
dest[3][2] = -(a * t[2] - b * t[4] + c * t[5]);
|
|
|
|
t[0] = g * l - k * h;
|
|
t[1] = f * l - j * h;
|
|
t[2] = f * k - j * g;
|
|
t[3] = e * l - i * h;
|
|
t[4] = e * k - i * g;
|
|
t[5] = e * j - i * f;
|
|
|
|
dest[0][3] = -(b * t[0] - c * t[1] + d * t[2]);
|
|
dest[1][3] = a * t[0] - c * t[3] + d * t[4];
|
|
dest[2][3] = -(a * t[1] - b * t[3] + d * t[5]);
|
|
dest[3][3] = a * t[2] - b * t[4] + c * t[5];
|
|
|
|
det = 1.0f /
|
|
(a * dest[0][0] + b * dest[1][0] + c * dest[2][0] + d * dest[3][0]);
|
|
|
|
dest[0][0] *= det;
|
|
dest[0][1] *= det;
|
|
dest[0][2] *= det;
|
|
dest[0][3] *= det;
|
|
dest[1][0] *= det;
|
|
dest[1][1] *= det;
|
|
dest[1][2] *= det;
|
|
dest[1][3] *= det;
|
|
dest[2][0] *= det;
|
|
dest[2][1] *= det;
|
|
dest[2][2] *= det;
|
|
dest[2][3] *= det;
|
|
dest[3][0] *= det;
|
|
dest[3][1] *= det;
|
|
dest[3][2] *= det;
|
|
dest[3][3] *= det;
|
|
|
|
return array_to_mat4x4(dest);
|
|
}
|