[PATCH libinput 06/11] util: add a couple of 3x3 matrix helper functions
Peter Hutterer
peter.hutterer at who-t.net
Thu Aug 28 16:51:11 PDT 2014
On Thu, Aug 28, 2014 at 03:04:30PM +0200, Hans de Goede wrote:
> Hi,
>
> On 08/27/2014 06:31 AM, Peter Hutterer wrote:
> > Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> > ---
> > src/libinput-util.h | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > test/misc.c | 78 ++++++++++++++++++++++++++++++++++++++++
> > 2 files changed, 178 insertions(+)
> >
> > diff --git a/src/libinput-util.h b/src/libinput-util.h
> > index 5d366b0..925b86e 100644
> > --- a/src/libinput-util.h
> > +++ b/src/libinput-util.h
> > @@ -25,6 +25,7 @@
> >
> > #include <unistd.h>
> > #include <math.h>
> > +#include <string.h>
> >
> > #include "libinput.h"
> >
> > @@ -179,4 +180,103 @@ long_set_bit_state(unsigned long *array, int bit, int state)
> > long_clear_bit(array, bit);
> > }
> >
> > +struct matrix {
> > + float val[3][3]; /* [row][col] */
> > +};
> > +
> > +static inline void
> > +matrix_init_identity(struct matrix *m)
> > +{
> > + memset(m, 0, sizeof(*m));
> > + m->val[0][0] = 1;
> > + m->val[1][1] = 1;
> > + m->val[2][2] = 1;
> > +}
> > +
> > +static inline void
> > +matrix_from_farray6(struct matrix *m, const float values[6])
> > +{
> > + matrix_init_identity(m);
> > + m->val[0][0] = values[0];
> > + m->val[0][1] = values[1];
> > + m->val[0][2] = values[2];
> > + m->val[1][0] = values[3];
> > + m->val[1][1] = values[4];
> > + m->val[1][2] = values[5];
> > +}
> > +
> > +static inline void
> > +matrix_init_scale(struct matrix *m, float sx, float sy)
> > +{
> > + matrix_init_identity(m);
> > + m->val[0][0] = sx;
> > + m->val[1][1] = sy;
> > +}
> > +
> > +static inline void
> > +matrix_init_translate(struct matrix *m, float x, float y)
> > +{
> > + matrix_init_identity(m);
> > + m->val[0][2] = x;
> > + m->val[1][2] = y;
> > +}
> > +
> > +static inline int
> > +matrix_is_identity(struct matrix *m)
> > +{
> > + return (m->val[0][0] == 1 &&
> > + m->val[0][1] == 0 &&
> > + m->val[0][2] == 0 &&
> > + m->val[1][0] == 0 &&
> > + m->val[1][1] == 1 &&
> > + m->val[1][2] == 0 &&
> > + m->val[2][0] == 0 &&
> > + m->val[2][1] == 0 &&
> > + m->val[2][2] == 1);
> > +}
> > +
> > +static inline void
> > +matrix_mult(struct matrix *dest,
> > + const struct matrix *m1,
> > + const struct matrix *m2)
> > +{
> > + struct matrix m;
> > + int row, col, i;
> > +
> > + for (row = 0; row < 3; row++) {
> > + for (col = 0; col < 3; col++) {
> > + double v = 0;
> > + for (i = 0; i < 3; i++) {
> > + v += m1->val[row][i] * m2->val[i][col];
> > + }
> > + m.val[row][col] = v;
> > + }
> > + }
> > +
> > + memcpy(dest, &m, sizeof(m));
>
> Why are you storing things in a local matrix first, and not
> directly into dest ?
I'll add that to the commit message but: it allows for dest == m1 or
dest == m2.
Cheers,
Peter
>
>
> > +}
> > +
> > +static inline void
> > +matrix_mult_vec(struct matrix *m, int *x, int *y)
> > +{
> > + int tx, ty;
> > +
> > + tx = *x * m->val[0][0] + *y * m->val[0][1] + m->val[0][2];
> > + ty = *x * m->val[1][0] + *y * m->val[1][1] + m->val[1][2];
> > +
> > + *x = tx;
> > + *y = ty;
> > +}
>
> Idem comment as for patch 5/11.
>
> Otherwise looks good.
>
> Regards,
>
> Hans
>
> > +
> > +static inline void
> > +matrix_to_farray6(const struct matrix *m, float out[6])
> > +{
> > + out[0] = m->val[0][0];
> > + out[1] = m->val[0][1];
> > + out[2] = m->val[0][2];
> > + out[3] = m->val[1][0];
> > + out[4] = m->val[1][1];
> > + out[5] = m->val[1][2];
> > +}
> > +
> > #endif /* LIBINPUT_UTIL_H */
> > diff --git a/test/misc.c b/test/misc.c
> > index 983c3f9..1512180 100644
> > --- a/test/misc.c
> > +++ b/test/misc.c
> > @@ -431,6 +431,83 @@ START_TEST(config_status_string)
> > }
> > END_TEST
> >
> > +START_TEST(matrix_helpers)
> > +{
> > + struct matrix m1, m2, m3;
> > + float f[6] = { 1, 2, 3, 4, 5, 6 };
> > + int x, y;
> > + int row, col;
> > +
> > + matrix_init_identity(&m1);
> > +
> > + for (row = 0; row < 3; row++) {
> > + for (col = 0; col < 3; col++) {
> > + ck_assert_int_eq(m1.val[row][col],
> > + (row == col) ? 1 : 0);
> > + }
> > + }
> > + ck_assert(matrix_is_identity(&m1));
> > +
> > + matrix_from_farray6(&m2, f);
> > + ck_assert_int_eq(m2.val[0][0], 1);
> > + ck_assert_int_eq(m2.val[0][1], 2);
> > + ck_assert_int_eq(m2.val[0][2], 3);
> > + ck_assert_int_eq(m2.val[1][0], 4);
> > + ck_assert_int_eq(m2.val[1][1], 5);
> > + ck_assert_int_eq(m2.val[1][2], 6);
> > + ck_assert_int_eq(m2.val[2][0], 0);
> > + ck_assert_int_eq(m2.val[2][1], 0);
> > + ck_assert_int_eq(m2.val[2][2], 1);
> > +
> > + x = 100;
> > + y = 5;
> > + matrix_mult_vec(&m1, &x, &y);
> > + ck_assert_int_eq(x, 100);
> > + ck_assert_int_eq(y, 5);
> > +
> > + matrix_mult(&m3, &m1, &m1);
> > + ck_assert(matrix_is_identity(&m3));
> > +
> > + matrix_init_scale(&m2, 2, 4);
> > + ck_assert_int_eq(m2.val[0][0], 2);
> > + ck_assert_int_eq(m2.val[0][1], 0);
> > + ck_assert_int_eq(m2.val[0][2], 0);
> > + ck_assert_int_eq(m2.val[1][0], 0);
> > + ck_assert_int_eq(m2.val[1][1], 4);
> > + ck_assert_int_eq(m2.val[1][2], 0);
> > + ck_assert_int_eq(m2.val[2][0], 0);
> > + ck_assert_int_eq(m2.val[2][1], 0);
> > + ck_assert_int_eq(m2.val[2][2], 1);
> > +
> > + matrix_mult_vec(&m2, &x, &y);
> > + ck_assert_int_eq(x, 200);
> > + ck_assert_int_eq(y, 20);
> > +
> > + matrix_init_translate(&m2, 10, 100);
> > + ck_assert_int_eq(m2.val[0][0], 1);
> > + ck_assert_int_eq(m2.val[0][1], 0);
> > + ck_assert_int_eq(m2.val[0][2], 10);
> > + ck_assert_int_eq(m2.val[1][0], 0);
> > + ck_assert_int_eq(m2.val[1][1], 1);
> > + ck_assert_int_eq(m2.val[1][2], 100);
> > + ck_assert_int_eq(m2.val[2][0], 0);
> > + ck_assert_int_eq(m2.val[2][1], 0);
> > + ck_assert_int_eq(m2.val[2][2], 1);
> > +
> > + matrix_mult_vec(&m2, &x, &y);
> > + ck_assert_int_eq(x, 210);
> > + ck_assert_int_eq(y, 120);
> > +
> > + matrix_to_farray6(&m2, f);
> > + ck_assert_int_eq(f[0], 1);
> > + ck_assert_int_eq(f[1], 0);
> > + ck_assert_int_eq(f[2], 10);
> > + ck_assert_int_eq(f[3], 0);
> > + ck_assert_int_eq(f[4], 1);
> > + ck_assert_int_eq(f[5], 100);
> > +}
> > +END_TEST
> > +
> > int main (int argc, char **argv) {
> > litest_add_no_device("events:conversion", event_conversion_device_notify);
> > litest_add_no_device("events:conversion", event_conversion_pointer);
> > @@ -441,5 +518,6 @@ int main (int argc, char **argv) {
> > litest_add("device:id", device_ids, LITEST_ANY, LITEST_ANY);
> > litest_add_no_device("config:status string", config_status_string);
> >
> > + litest_add_no_device("misc:matrix", matrix_helpers);
> > return litest_run(argc, argv);
> > }
> >
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