123 lines
3.7 KiB
C
123 lines
3.7 KiB
C
#include "gryphn_mat4.h"
|
|
#include "math.h"
|
|
|
|
gnMat4x4 gnIdentity(void) {
|
|
return (gnMat4x4){
|
|
.mat = {
|
|
{ 1.0f, 0.0f, 0.0f, 0.0f },
|
|
{ 0.0f, 1.0f, 0.0f, 0.0f },
|
|
{ 0.0f, 0.0f, 1.0f, 0.0f },
|
|
{ 0.0f, 0.0f, 0.0f, 1.0f }
|
|
}
|
|
};
|
|
}
|
|
|
|
gnMat4x4 gnOrthographic(
|
|
float left, float right, float top, float bottom, float near, float far
|
|
) {
|
|
return (gnMat4x4){
|
|
.mat = {
|
|
{ (2)/(right-left), 0.0f, 0.0f, -((right+left)/(right-left)) },
|
|
{ 0.0f, 2/(top-bottom), 0.0f, -((top+bottom)/(top-bottom)) },
|
|
{ 0.0f, 0.0f, -2/(far-near), -((far+near)/(far-near)) },
|
|
{ 0.0f, 0.0f, 0.0f, 1.0f }
|
|
}
|
|
};
|
|
}
|
|
|
|
gnMat4x4 gnProjection(
|
|
float fov, float aspect, float near, float far
|
|
) {
|
|
float f = 1.0f / tan(fov * 0.5f);
|
|
|
|
return (gnMat4x4){
|
|
.mat = {
|
|
{ f / aspect, 0.0f, 0.0f, 0.0f },
|
|
{ 0.0f , f , 0.0f, 0.0f },
|
|
{ 0.0f , 0.0f, (far + near) / (near - far), -1.0f },
|
|
{ 0.0f , 0.0f, (2 * far * near) / (near - far), 0.0f }
|
|
}
|
|
};
|
|
}
|
|
|
|
gnMat4x4 gnTranslate(gnVec3 translation) {
|
|
return (gnMat4x4) {
|
|
.mat = {
|
|
{ 1.0f, 0.0f, 0.0f, 0.0f },
|
|
{ 0.0f, 1.0f, 0.0f, 0.0f },
|
|
{ 0.0f, 0.0f, 1.0f, 0.0f },
|
|
{ translation.x, translation.y, translation.z, 1.0f }
|
|
}
|
|
};
|
|
}
|
|
// this function was heavily adapted from GLMs implementation
|
|
gnMat4x4 gnRotate(gnVec3 axis, float rotation) {
|
|
float c = cos(rotation), s = sin(rotation);
|
|
|
|
axis = gnVec3Normalize(axis);
|
|
gnVec3 temp = {
|
|
.x = ((1.0f - c) * axis.x),
|
|
.y = ((1.0f - c) * axis.y),
|
|
.z = ((1.0f - c) * axis.z)
|
|
};
|
|
|
|
gnMat4 rotate = {
|
|
.mat = {
|
|
{ c + temp.x * axis.x, temp.x * axis.y + s * axis.z, temp.x * axis.z - s * axis.y, 0.0f },
|
|
{ temp.y * axis.x - s * axis.z, c + temp.y * axis.y, temp.y * axis.z + s * axis.x, 0.0f },
|
|
{ temp.z * axis.x + s * axis.y, temp.z * axis.y - s * axis.x, c + temp.z * axis.z, 0.0f },
|
|
{ 0.0f, 0.0f, 0.0f, 1.0f },
|
|
}
|
|
};
|
|
return rotate;
|
|
}
|
|
|
|
gnMat4x4 gnScale(gnVec3 amount) {
|
|
gnMat4 rotate = {
|
|
.mat = {
|
|
{ amount.x, 0.0f, 0.0f, 0.0f },
|
|
{ 0.0f, amount.y, 0.0f, 0.0f },
|
|
{ 0.0f, 0.0f, amount.z, 0.0f },
|
|
{ 0.0f, 0.0f, 0.0f, 1.0f }
|
|
}
|
|
};
|
|
return rotate;
|
|
}
|
|
|
|
// used GLMs lookAtLH from /glm/ext/matrix_transform.inl as a base
|
|
gnMat4x4 gnLookAt(gnVec3 eye, gnVec3 center, gnVec3 up) {
|
|
const gnVec3 f = gnVec3Normalize(gnVec3Subtract(center, eye));
|
|
const gnVec3 s = gnVec3Normalize(gnVec3Cross(f, up));
|
|
const gnVec3 u = gnVec3Cross(s, f);
|
|
|
|
return (gnMat4x4) {
|
|
.mat = {
|
|
{ s.x, u.x, -f.x, 0.0f },
|
|
{ s.y, u.y, -f.y, 0.0f },
|
|
{ s.z, u.z, -f.z, 0.0f },
|
|
{ -gnVec3Dot(s, eye), -gnVec3Dot(u, eye), gnVec3Dot(f, eye), 1.0f }
|
|
}
|
|
};
|
|
}
|
|
|
|
gnMat4x4 gnMultiply(gnMat4 a, gnMat4 b) {
|
|
gnMat4 result;
|
|
|
|
for (int row = 0; row < 4; ++row)
|
|
for (int col = 0; col < 4; ++col)
|
|
result.mat[row][col] = a.mat[row][0] * b.mat[0][col] +
|
|
a.mat[row][1] * b.mat[1][col] +
|
|
a.mat[row][2] * b.mat[2][col] +
|
|
a.mat[row][3] * b.mat[3][col];
|
|
|
|
return result;
|
|
}
|
|
|
|
gnVec3 gnMat4MultiplyVec3(gnMat4 m, gnVec3 v) {
|
|
gnVec3 result;
|
|
result.x = m.mat[0][0] * v.x + m.mat[1][0] * v.y + m.mat[2][0] * v.z + m.mat[3][0];
|
|
result.y = m.mat[0][1] * v.x + m.mat[1][1] * v.y + m.mat[2][1] * v.z + m.mat[3][1];
|
|
result.z = m.mat[0][2] * v.x + m.mat[1][2] * v.y + m.mat[2][2] * v.z + m.mat[3][2];
|
|
return result;
|
|
}
|