mutter/common/cogl-matrix.c
Havoc Pennington 11349b6c74 Virtualize GL matrix operations and use a client-side matrix when GL is indirect
This is useful because sometimes we need to get the current matrix, which
is too expensive when indirect rendering.

In addition, this virtualization makes it easier to clean up the API in
the future.
2009-03-12 18:32:45 +00:00

197 lines
5.5 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_frustum (CoglMatrix *matrix,
float left,
float right,
float bottom,
float top,
float z_near,
float z_far)
{
float x, y, a, b, c, d;
CoglMatrix frustum;
x = (2.0f * z_near) / (right - left);
y = (2.0f * z_near) / (top - bottom);
a = (right + left) / (right - left);
b = (top + bottom) / (top - bottom);
c = -(z_far + z_near) / ( z_far - z_near);
d = -(2.0f * z_far* z_near) / (z_far - z_near);
frustum.xx = x;
frustum.yx = 0.0f;
frustum.zx = 0.0f;
frustum.wx = 0.0f;
frustum.xy = 0.0f;
frustum.yy = y;
frustum.zy = 0.0f;
frustum.wy = 0.0f;
frustum.xz = a;
frustum.yz = b;
frustum.zz = c;
frustum.wz = -1.0f;
frustum.xw = 0.0f;
frustum.yw = 0.0f;
frustum.zw = d;
frustum.ww = 0.0f;
cogl_matrix_multiply (matrix, matrix, &frustum);
}
void
cogl_matrix_init_from_array (CoglMatrix *matrix, const float *array)
{
memcpy (matrix, array, sizeof (float) * 16);
}
const float *
cogl_matrix_get_array (const CoglMatrix *matrix)
{
return (float *)matrix;
}