/*
* Builds a translation matrix. All other elements in
* the matrix will be set to zero except for the
* diagonal which is set to 1.0
*/
void matrix_4x4_translate(math_matrix_4x4 *out, float x,
float y, float z)
{
matrix_4x4_identity(out);
MAT_ELEM_4X4(*out, 0, 3) = x;
MAT_ELEM_4X4(*out, 1, 3) = y;
MAT_ELEM_4X4(*out, 2, 3) = z;
}
void matrix_4x4_copy(math_matrix_4x4 *dst, const math_matrix_4x4 *src)
{
unsigned i, j;
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++)
MAT_ELEM_4X4(*dst, i, j) = MAT_ELEM_4X4(*src, i, j);
}
void matrix_4x4_scale(math_matrix_4x4 *out, float x, float y,
float z)
{
memset(out, 0, sizeof(*out));
MAT_ELEM_4X4(*out, 0, 0) = x;
MAT_ELEM_4X4(*out, 1, 1) = y;
MAT_ELEM_4X4(*out, 2, 2) = z;
MAT_ELEM_4X4(*out, 3, 3) = 1.0f;
}
/*
* Sets out to the transposed matrix of in
*/
void matrix_4x4_transpose(math_matrix_4x4 *out, const math_matrix_4x4 *in)
{
unsigned i, j;
math_matrix_4x4 mat;
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++)
MAT_ELEM_4X4(mat, j, i) = MAT_ELEM_4X4(*in, i, j);
*out = mat;
}
/*
* Builds a rotation matrix using the
* rotation around the Z-axis.
*/
void matrix_4x4_rotate_z(math_matrix_4x4 *mat, float rad)
{
float cosine = cosf(rad);
float sine = sinf(rad);
matrix_4x4_identity(mat);
MAT_ELEM_4X4(*mat, 0, 0) = cosine;
MAT_ELEM_4X4(*mat, 1, 1) = cosine;
MAT_ELEM_4X4(*mat, 0, 1) = -sine;
MAT_ELEM_4X4(*mat, 1, 0) = sine;
}
/*
* Creates a perspective projection matrix.
*/
void matrix_4x4_projection(math_matrix_4x4 *out, float znear,
float zfar)
{
float delta_z = zfar - znear;
memset(out, 0, sizeof(*out));
MAT_ELEM_4X4(*out, 0, 0) = znear;
MAT_ELEM_4X4(*out, 1, 1) = zfar;
MAT_ELEM_4X4(*out, 2, 2) = (zfar + znear) / delta_z;
MAT_ELEM_4X4(*out, 2, 3) = -2.0f * zfar * znear / delta_z;
MAT_ELEM_4X4(*out, 3, 2) = -1.0f;
}
/*
* Creates a perspective projection matrix.
*/
void matrix_4x4_projection(math_matrix_4x4 *out,
float y_fov,
float aspect,
float znear,
float zfar)
{
float const a = 1.f / tan(y_fov / 2.f);
float delta_z = zfar - znear;
memset(out, 0, sizeof(*out));
MAT_ELEM_4X4(*out, 0, 0) = a / aspect;
MAT_ELEM_4X4(*out, 1, 1) = a;
MAT_ELEM_4X4(*out, 2, 2) = -((zfar + znear) / delta_z);
MAT_ELEM_4X4(*out, 2, 3) = -1.f;
MAT_ELEM_4X4(*out, 3, 2) = -((2.f * zfar * znear) / delta_z);
}
/*
* Sets mat to an identity matrix
*/
void matrix_4x4_identity(math_matrix_4x4 *mat)
{
unsigned i;
memset(mat, 0, sizeof(*mat));
for (i = 0; i < 4; i++)
MAT_ELEM_4X4(*mat, i, i) = 1.0f;
}
/*
* Multiplies a with b, stores the result in out
*/
void matrix_4x4_multiply(
math_matrix_4x4 *out,
const math_matrix_4x4 *a,
const math_matrix_4x4 *b)
{
unsigned r, c, k;
math_matrix_4x4 mat;
for (r = 0; r < 4; r++)
{
for (c = 0; c < 4; c++)
{
float dot = 0.0f;
for (k = 0; k < 4; k++)
dot += MAT_ELEM_4X4(*a, r, k) * MAT_ELEM_4X4(*b, k, c);
MAT_ELEM_4X4(mat, r, c) = dot;
}
}
*out = mat;
}
/* TODO/FIXME - finish */
void matrix_4x4_lookat(math_matrix_4x4 *out,
vec3_t eye,
vec3_t center,
vec3_t up)
{
vec3_t s, t, f;
vec3_copy(&f[0], center);
vec3_subtract(&f[0], eye);
vec3_normalize(&f[0]);
vec3_cross(&s[0], &f[0], up);
vec3_normalize(&s[0]);
vec3_cross(&t[0], &s[0], f);
memset(out, 0, sizeof(*out));
MAT_ELEM_4X4(*out, 0, 0) = s[0];
MAT_ELEM_4X4(*out, 0, 1) = t[0];
MAT_ELEM_4X4(*out, 0, 2) = -f[0];
MAT_ELEM_4X4(*out, 1, 0) = s[1];
MAT_ELEM_4X4(*out, 1, 1) = t[1];
MAT_ELEM_4X4(*out, 1, 2) = -f[1];
MAT_ELEM_4X4(*out, 2, 0) = s[2];
MAT_ELEM_4X4(*out, 2, 1) = t[2];
MAT_ELEM_4X4(*out, 2, 2) = -f[2];
MAT_ELEM_4X4(*out, 3, 3) = 1.f;
#if 0
mat4x4_translate_in_place(m, -eye[0], -eye[1], -eye[2]);
#endif
}
/*
* Creates an orthographic projection matrix.
*/
void matrix_4x4_ortho(math_matrix_4x4 *mat,
float left, float right,
float bottom, float top,
float znear, float zfar)
{
float rl = right - left;
float tb = top - bottom;
float fn = zfar - znear;
matrix_4x4_identity(mat);
MAT_ELEM_4X4(*mat, 0, 0) = 2.0f / rl;
MAT_ELEM_4X4(*mat, 1, 1) = 2.0f / tb;
MAT_ELEM_4X4(*mat, 2, 2) = -2.0f / fn;
MAT_ELEM_4X4(*mat, 0, 3) = -(left + right) / rl;
MAT_ELEM_4X4(*mat, 1, 3) = -(top + bottom) / tb;
MAT_ELEM_4X4(*mat, 2, 3) = -(zfar + znear) / fn;
}
/*
* Creates an orthographic projection matrix.
*/
void matrix_4x4_ortho(math_matrix_4x4 *mat,
float left, float right,
float bottom, float top,
float znear, float zfar)
{
float tx, ty, tz;
matrix_4x4_identity(mat);
tx = -(right + left) / (right - left);
ty = -(top + bottom) / (top - bottom);
tz = -(zfar + znear) / (zfar - znear);
MAT_ELEM_4X4(*mat, 0, 0) = 2.0f / (right - left);
MAT_ELEM_4X4(*mat, 1, 1) = 2.0f / (top - bottom);
MAT_ELEM_4X4(*mat, 2, 2) = -2.0f / (zfar - znear);
MAT_ELEM_4X4(*mat, 0, 3) = tx;
MAT_ELEM_4X4(*mat, 1, 3) = ty;
MAT_ELEM_4X4(*mat, 2, 3) = tz;
}
/*
* Builds a rotation matrix using the
* rotation around the Y-axis.
*/
void matrix_4x4_rotate_y(math_matrix_4x4 *mat, float rad)
{
float cosine = cosf(rad);
float sine = sinf(rad);
MAT_ELEM_4X4(*mat, 0, 0) = cosine;
MAT_ELEM_4X4(*mat, 0, 1) = 0.0f;
MAT_ELEM_4X4(*mat, 0, 2) = -sine;
MAT_ELEM_4X4(*mat, 0, 3) = 0.0f;
MAT_ELEM_4X4(*mat, 1, 0) = 0.0f;
MAT_ELEM_4X4(*mat, 1, 1) = 1.0f;
MAT_ELEM_4X4(*mat, 1, 2) = 0.0f;
MAT_ELEM_4X4(*mat, 1, 3) = 0.0f;
MAT_ELEM_4X4(*mat, 2, 0) = sine;
MAT_ELEM_4X4(*mat, 2, 1) = 0.0f;
MAT_ELEM_4X4(*mat, 2, 2) = cosine;
MAT_ELEM_4X4(*mat, 2, 3) = 0.0f;
MAT_ELEM_4X4(*mat, 3, 0) = 0.0f;
MAT_ELEM_4X4(*mat, 3, 1) = 0.0f;
MAT_ELEM_4X4(*mat, 3, 2) = 0.0f;
MAT_ELEM_4X4(*mat, 3, 3) = 1.0f;
}
void matrix_4x4_lookat(math_matrix_4x4 *out,
vec3_t eye,
vec3_t center,
vec3_t up)
{
vec3_t zaxis; /* the "forward" vector */
vec3_t xaxis; /* the "right" vector */
vec3_t yaxis; /* the "up" vector */
vec3_copy(&zaxis[0], center);
vec3_subtract(&zaxis[0], eye);
vec3_normalize(&zaxis[0]);
vec3_cross(&xaxis[0], &zaxis[0], up);
vec3_normalize(&xaxis[0]);
vec3_cross(&yaxis[0], &xaxis[0], zaxis);
MAT_ELEM_4X4(*out, 0, 0) = xaxis[0];
MAT_ELEM_4X4(*out, 0, 1) = yaxis[0];
MAT_ELEM_4X4(*out, 0, 2) = -zaxis[0];
MAT_ELEM_4X4(*out, 0, 3) = 0.0;
MAT_ELEM_4X4(*out, 1, 0) = xaxis[1];
MAT_ELEM_4X4(*out, 1, 1) = yaxis[1];
MAT_ELEM_4X4(*out, 1, 2) = -zaxis[1];
MAT_ELEM_4X4(*out, 1, 3) = 0.0f;
MAT_ELEM_4X4(*out, 2, 0) = xaxis[2];
MAT_ELEM_4X4(*out, 2, 1) = yaxis[2];
MAT_ELEM_4X4(*out, 2, 2) = -zaxis[2];
MAT_ELEM_4X4(*out, 2, 3) = 0.0f;
MAT_ELEM_4X4(*out, 3, 0) = -(xaxis[0] * eye[0] + xaxis[1] * eye[1] + xaxis[2] * eye[2]);
MAT_ELEM_4X4(*out, 3, 1) = -(yaxis[0] * eye[0] + yaxis[1] * eye[1] + yaxis[2] * eye[2]);
MAT_ELEM_4X4(*out, 3, 2) = -(zaxis[0] * eye[0] + zaxis[1] * eye[1] + zaxis[2] * eye[2]);
MAT_ELEM_4X4(*out, 3, 3) = 1.f;
}
/*
* Builds a translation matrix. All other elements in
* the matrix will be set to zero except for the
* diagonal which is set to 1.0
*/
void matrix_4x4_translate(math_matrix_4x4 *out, float x,
float y, float z)
{
MAT_ELEM_4X4(*out, 0, 0) = 1.0f;
MAT_ELEM_4X4(*out, 0, 1) = 0.0f;
MAT_ELEM_4X4(*out, 0, 2) = 0.0f;
MAT_ELEM_4X4(*out, 0, 3) = x;
MAT_ELEM_4X4(*out, 1, 0) = 0.0f;
MAT_ELEM_4X4(*out, 1, 1) = 1.0f;
MAT_ELEM_4X4(*out, 1, 2) = 1.0f;
MAT_ELEM_4X4(*out, 1, 3) = y;
MAT_ELEM_4X4(*out, 2, 0) = 0.0f;
MAT_ELEM_4X4(*out, 2, 1) = 0.0f;
MAT_ELEM_4X4(*out, 2, 2) = 1.0f;
MAT_ELEM_4X4(*out, 2, 3) = z;
MAT_ELEM_4X4(*out, 3, 0) = 0.0f;
MAT_ELEM_4X4(*out, 3, 1) = 0.0f;
MAT_ELEM_4X4(*out, 3, 2) = 0.0f;
MAT_ELEM_4X4(*out, 3, 3) = 1.0f;
}
