mutter/common/cogl-matrix.c
Robert Bragg e91fe8817d [Cogl] the cogl_get_*_matrix functions now work with CoglMatrix types
Since the CoglMatrix type was added for supporting texture matrices recently
it made sense to be consistent accross the Cogl API and use the Cogl type
over the GL style GLfloat m[16] arrays.
2009-02-23 10:49:35 +00:00

155 lines
4.6 KiB
C

#include <cogl-matrix.h>
#include <glib.h>
#include <math.h>
#include <string.h>
void
cogl_matrix_init_identity (CoglMatrix *matrix)
{
matrix->xx = 1; matrix->xy = 0; matrix->xz = 0; matrix->xw = 0;
matrix->yx = 0; matrix->yy = 1; matrix->yz = 0; matrix->yw = 0;
matrix->zx = 0; matrix->zy = 0; matrix->zz = 1; matrix->zw = 0;
matrix->wx = 0; matrix->wy = 0; matrix->wz = 0; matrix->ww = 1;
}
void
cogl_matrix_multiply (CoglMatrix *result,
const CoglMatrix *a,
const CoglMatrix *b)
{
CoglMatrix r;
/* row 0 */
r.xx = a->xx * b->xx + a->xy * b->yx + a->xz * b->zx + a->xw * b->wx;
r.xy = a->xx * b->xy + a->xy * b->yy + a->xz * b->zy + a->xw * b->wy;
r.xz = a->xx * b->xz + a->xy * b->yz + a->xz * b->zz + a->xw * b->wz;
r.xw = a->xx * b->xw + a->xy * b->yw + a->xz * b->zw + a->xw * b->ww;
/* row 1 */
r.yx = a->yx * b->xx + a->yy * b->yx + a->yz * b->zx + a->yw * b->wx;
r.yy = a->yx * b->xy + a->yy * b->yy + a->yz * b->zy + a->yw * b->wy;
r.yz = a->yx * b->xz + a->yy * b->yz + a->yz * b->zz + a->yw * b->wz;
r.yw = a->yx * b->xw + a->yy * b->yw + a->yz * b->zw + a->yw * b->ww;
/* row 2 */
r.zx = a->zx * b->xx + a->zy * b->yx + a->zz * b->zx + a->zw * b->wx;
r.zy = a->zx * b->xy + a->zy * b->yy + a->zz * b->zy + a->zw * b->wy;
r.zz = a->zx * b->xz + a->zy * b->yz + a->zz * b->zz + a->zw * b->wz;
r.zw = a->zx * b->xw + a->zy * b->yw + a->zz * b->zw + a->zw * b->ww;
/* row 3 */
r.wx = a->wx * b->xx + a->wy * b->yx + a->wz * b->zx + a->ww * b->wx;
r.wy = a->wx * b->xy + a->wy * b->yy + a->wz * b->zy + a->ww * b->wy;
r.wz = a->wx * b->xz + a->wy * b->yz + a->wz * b->zz + a->ww * b->wz;
r.ww = a->wx * b->xw + a->wy * b->yw + a->wz * b->zw + a->ww * b->ww;
/* The idea was that having this unrolled; it might be easier for the
* compiler to vectorize, but that's probably not true. Mesa does it
* using a single for (i=0; i<4; i++) approach, may that's better...
*/
*result = r;
}
void
cogl_matrix_rotate (CoglMatrix *matrix,
float angle,
float x,
float y,
float z)
{
CoglMatrix rotation;
CoglMatrix result;
angle *= G_PI / 180.0f;
float c = cosf (angle);
float s = sinf (angle);
rotation.xx = x * x * (1.0f - c) + c;
rotation.yx = y * x * (1.0f - c) + z * s;
rotation.zx = x * z * (1.0f - c) - y * s;
rotation.wx = 0.0f;
rotation.xy = x * y * (1.0f - c) - z * s;
rotation.yy = y * y * (1.0f - c) + c;
rotation.zy = y * z * (1.0f - c) + x * s;
rotation.wy = 0.0f;
rotation.xz = x * z * (1.0f - c) + y * s;
rotation.yz = y * z * (1.0f - c) - x * s;
rotation.zz = z * z * (1.0f - c) + c;
rotation.wz = 0.0f;
rotation.xw = 0.0f;
rotation.yw = 0.0f;
rotation.zw = 0.0f;
rotation.ww = 1.0f;
cogl_matrix_multiply (&result, matrix, &rotation);
*matrix = result;
}
void
cogl_matrix_translate (CoglMatrix *matrix,
float x,
float y,
float z)
{
matrix->xw = matrix->xx * x + matrix->xy * y + matrix->xz * z + matrix->xw;
matrix->yw = matrix->yx * x + matrix->yy * y + matrix->yz * z + matrix->yw;
matrix->zw = matrix->zx * x + matrix->zy * y + matrix->zz * z + matrix->zw;
matrix->ww = matrix->wx * x + matrix->wy * y + matrix->wz * z + matrix->ww;
}
void
cogl_matrix_scale (CoglMatrix *matrix,
float sx,
float sy,
float sz)
{
matrix->xx *= sx; matrix->xy *= sy; matrix->xz *= sz;
matrix->yx *= sx; matrix->yy *= sy; matrix->yz *= sz;
matrix->zx *= sx; matrix->zy *= sy; matrix->zz *= sz;
matrix->wx *= sx; matrix->wy *= sy; matrix->wz *= sz;
}
#if 0
gboolean
cogl_matrix_invert (CoglMatrix *matrix)
{
/* TODO */
/* Note: It might be nice to also use the flag based tricks that mesa does
* to alow it to track the type of transformations a matrix represents
* so it can use various assumptions to optimise the inversion.
*/
}
#endif
void
cogl_matrix_transform_point (const CoglMatrix *matrix,
float *x,
float *y,
float *z,
float *w)
{
float _x = *x, _y = *y, _z = *z, _w = *w;
*x = matrix->xx * _x + matrix->xy * _y + matrix->xz * _z + matrix->xw * _w;
*y = matrix->yx * _x + matrix->yy * _y + matrix->yz * _z + matrix->yw * _w;
*z = matrix->zx * _x + matrix->zy * _y + matrix->zz * _z + matrix->zw * _w;
*w = matrix->wx * _x + matrix->wy * _y + matrix->wz * _z + matrix->ww * _w;
}
void
cogl_matrix_init_from_gl_matrix (CoglMatrix *matrix, const float *gl_matrix)
{
memcpy (matrix, gl_matrix, sizeof (float) * 16);
}
const float *
cogl_matrix_get_gl_matrix (const CoglMatrix *matrix)
{
return (float *)matrix;
}