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gtk/gsk/gsktransform.c
Sergey Bugaev d07a6b8566 snapshot, gsktransform: Mention that rotation happens around (0, 0) 
...and not around the center of the render node, as one could expect
given that the render node syntax for rotation, transform: rotate(90);,
happens to match the CSS syntax for the same thing, and CSS does rotate
around the center by default.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
2023-08-25 15:54:05 +03:00

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/*
* Copyright © 2019 Benjamin Otte
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
* Authors: Benjamin Otte <otte@gnome.org>
*/
/**
* GskTransform: (ref-func gsk_transform_ref) (unref-func gsk_transform_unref)
*
* `GskTransform` is an object to describe transform matrices.
*
* Unlike `graphene_matrix_t`, `GskTransform` retains the steps in how
* a transform was constructed, and allows inspecting them. It is modeled
* after the way CSS describes transforms.
*
* `GskTransform` objects are immutable and cannot be changed after creation.
* This means code can safely expose them as properties of objects without
* having to worry about others changing them.
*/
#include "config.h"
#include "gsktransformprivate.h"
/* {{{ Boilerplate */
struct _GskTransformClass
{
gsize struct_size;
const char *type_name;
void (* finalize) (GskTransform *transform);
void (* to_matrix) (GskTransform *transform,
graphene_matrix_t *out_matrix);
void (* apply_2d) (GskTransform *transform,
float *out_xx,
float *out_yx,
float *out_xy,
float *out_yy,
float *out_dx,
float *out_dy);
void (* apply_affine) (GskTransform *transform,
float *out_scale_x,
float *out_scale_y,
float *out_dx,
float *out_dy);
void (* apply_translate) (GskTransform *transform,
float *out_dx,
float *out_dy);
void (* print) (GskTransform *transform,
GString *string);
GskTransform * (* apply) (GskTransform *transform,
GskTransform *apply_to);
GskTransform * (* invert) (GskTransform *transform,
GskTransform *next);
/* both matrices have the same type */
gboolean (* equal) (GskTransform *first_transform,
GskTransform *second_transform);
};
G_DEFINE_BOXED_TYPE (GskTransform, gsk_transform,
gsk_transform_ref,
gsk_transform_unref)
static gboolean
gsk_transform_is_identity (GskTransform *self);
static GskTransform *
gsk_transform_matrix_with_category (GskTransform *next,
const graphene_matrix_t*matrix,
GskTransformCategory category);
static inline gboolean
gsk_transform_has_class (GskTransform *self,
const GskTransformClass *transform_class)
{
return self != NULL && self->transform_class == transform_class;
}
/*< private >
* gsk_transform_alloc:
* @transform_class: class structure for this self
* @category: The category of this transform. Will be used to initialize
* the result's category together with &next's category
* @next: (transfer full) (nullable): Next transform to multiply with
*
* Returns: (transfer full): the newly created `GskTransform`
*/
static gpointer
gsk_transform_alloc (const GskTransformClass *transform_class,
GskTransformCategory category,
GskTransform *next)
{
GskTransform *self;
g_return_val_if_fail (transform_class != NULL, NULL);
self = g_atomic_rc_box_alloc0 (transform_class->struct_size);
self->transform_class = transform_class;
self->category = next ? MIN (category, next->category) : category;
if (gsk_transform_is_identity (next))
gsk_transform_unref (next);
else
self->next = next;
return self;
}
static void
gsk_transform_finalize (GskTransform *self)
{
self->transform_class->finalize (self);
gsk_transform_unref (self->next);
}
/* }}} */
/* {{{ IDENTITY */
static void
gsk_identity_transform_finalize (GskTransform *transform)
{
}
static void
gsk_identity_transform_to_matrix (GskTransform *transform,
graphene_matrix_t *out_matrix)
{
graphene_matrix_init_identity (out_matrix);
}
static void
gsk_identity_transform_apply_2d (GskTransform *transform,
float *out_xx,
float *out_yx,
float *out_xy,
float *out_yy,
float *out_dx,
float *out_dy)
{
}
static void
gsk_identity_transform_apply_affine (GskTransform *transform,
float *out_scale_x,
float *out_scale_y,
float *out_dx,
float *out_dy)
{
}
static void
gsk_identity_transform_apply_translate (GskTransform *transform,
float *out_dx,
float *out_dy)
{
}
static void
gsk_identity_transform_print (GskTransform *transform,
GString *string)
{
g_string_append (string, "none");
}
static GskTransform *
gsk_identity_transform_apply (GskTransform *transform,
GskTransform *apply_to)
{
/* We do the following to make sure inverting a non-NULL transform
* will return a non-NULL transform.
*/
if (apply_to)
return apply_to;
else
return gsk_transform_new ();
}
static GskTransform *
gsk_identity_transform_invert (GskTransform *transform,
GskTransform *next)
{
/* We do the following to make sure inverting a non-NULL transform
* will return a non-NULL transform.
*/
if (next)
return next;
else
return gsk_transform_new ();
}
static gboolean
gsk_identity_transform_equal (GskTransform *first_transform,
GskTransform *second_transform)
{
return TRUE;
}
static const GskTransformClass GSK_IDENTITY_TRANSFORM_CLASS =
{
sizeof (GskTransform),
"GskIdentityTransform",
gsk_identity_transform_finalize,
gsk_identity_transform_to_matrix,
gsk_identity_transform_apply_2d,
gsk_identity_transform_apply_affine,
gsk_identity_transform_apply_translate,
gsk_identity_transform_print,
gsk_identity_transform_apply,
gsk_identity_transform_invert,
gsk_identity_transform_equal,
};
/*<private>
* gsk_transform_is_identity:
* @transform: (nullable): A transform
*
* Checks if the transform is a representation of the identity
* transform.
*
* This is different from a transform like `scale(2) scale(0.5)`
* which just results in an identity transform when simplified.
*
* Returns: %TRUE if this transform is a representation of
* the identity transform
**/
static gboolean
gsk_transform_is_identity (GskTransform *self)
{
return self == NULL ||
(self->transform_class == &GSK_IDENTITY_TRANSFORM_CLASS && gsk_transform_is_identity (self->next));
}
/* }}} */
/* {{{ MATRIX */
typedef struct _GskMatrixTransform GskMatrixTransform;
struct _GskMatrixTransform
{
GskTransform parent;
graphene_matrix_t matrix;
};
static void
gsk_matrix_transform_finalize (GskTransform *self)
{
}
static void
gsk_matrix_transform_to_matrix (GskTransform *transform,
graphene_matrix_t *out_matrix)
{
GskMatrixTransform *self = (GskMatrixTransform *) transform;
graphene_matrix_init_from_matrix (out_matrix, &self->matrix);
}
static void
gsk_matrix_transform_apply_2d (GskTransform *transform,
float *out_xx,
float *out_yx,
float *out_xy,
float *out_yy,
float *out_dx,
float *out_dy)
{
GskMatrixTransform *self = (GskMatrixTransform *) transform;
graphene_matrix_t mat;
graphene_matrix_init_from_2d (&mat,
*out_xx, *out_yx,
*out_xy, *out_yy,
*out_dx, *out_dy);
graphene_matrix_multiply (&self->matrix, &mat, &mat);
/* not using graphene_matrix_to_2d() because it may
* fail the is_2d() check due to improper rounding */
*out_xx = graphene_matrix_get_value (&mat, 0, 0);
*out_yx = graphene_matrix_get_value (&mat, 0, 1);
*out_xy = graphene_matrix_get_value (&mat, 1, 0);
*out_yy = graphene_matrix_get_value (&mat, 1, 1);
*out_dx = graphene_matrix_get_value (&mat, 3, 0);
*out_dy = graphene_matrix_get_value (&mat, 3, 1);
}
static void
gsk_matrix_transform_apply_affine (GskTransform *transform,
float *out_scale_x,
float *out_scale_y,
float *out_dx,
float *out_dy)
{
GskMatrixTransform *self = (GskMatrixTransform *) transform;
switch (transform->category)
{
case GSK_TRANSFORM_CATEGORY_UNKNOWN:
case GSK_TRANSFORM_CATEGORY_ANY:
case GSK_TRANSFORM_CATEGORY_3D:
case GSK_TRANSFORM_CATEGORY_2D:
default:
g_assert_not_reached ();
break;
case GSK_TRANSFORM_CATEGORY_2D_AFFINE:
*out_dx += *out_scale_x * graphene_matrix_get_x_translation (&self->matrix);
*out_dy += *out_scale_y * graphene_matrix_get_y_translation (&self->matrix);
*out_scale_x *= graphene_matrix_get_x_scale (&self->matrix);
*out_scale_y *= graphene_matrix_get_y_scale (&self->matrix);
break;
case GSK_TRANSFORM_CATEGORY_2D_TRANSLATE:
*out_dx += *out_scale_x * graphene_matrix_get_x_translation (&self->matrix);
*out_dy += *out_scale_y * graphene_matrix_get_y_translation (&self->matrix);
break;
case GSK_TRANSFORM_CATEGORY_IDENTITY:
break;
}
}
static void
gsk_matrix_transform_apply_translate (GskTransform *transform,
float *out_dx,
float *out_dy)
{
GskMatrixTransform *self = (GskMatrixTransform *) transform;
switch (transform->category)
{
case GSK_TRANSFORM_CATEGORY_UNKNOWN:
case GSK_TRANSFORM_CATEGORY_ANY:
case GSK_TRANSFORM_CATEGORY_3D:
case GSK_TRANSFORM_CATEGORY_2D:
case GSK_TRANSFORM_CATEGORY_2D_AFFINE:
default:
g_assert_not_reached ();
break;
case GSK_TRANSFORM_CATEGORY_2D_TRANSLATE:
*out_dx += graphene_matrix_get_x_translation (&self->matrix);
*out_dy += graphene_matrix_get_y_translation (&self->matrix);
break;
case GSK_TRANSFORM_CATEGORY_IDENTITY:
break;
}
}
static void
string_append_double (GString *string,
double d)
{
char buf[G_ASCII_DTOSTR_BUF_SIZE];
g_ascii_formatd (buf, G_ASCII_DTOSTR_BUF_SIZE, "%g", d);
g_string_append (string, buf);
}
static void
gsk_matrix_transform_print (GskTransform *transform,
GString *string)
{
GskMatrixTransform *self = (GskMatrixTransform *) transform;
guint i;
float f[16];
g_string_append (string, "matrix3d(");
graphene_matrix_to_float (&self->matrix, f);
for (i = 0; i < 16; i++)
{
if (i > 0)
g_string_append (string, ", ");
string_append_double (string, f[i]);
}
g_string_append (string, ")");
}
static GskTransform *
gsk_matrix_transform_apply (GskTransform *transform,
GskTransform *apply_to)
{
GskMatrixTransform *self = (GskMatrixTransform *) transform;
return gsk_transform_matrix_with_category (apply_to,
&self->matrix,
transform->category);
}
static GskTransform *
gsk_matrix_transform_invert (GskTransform *transform,
GskTransform *next)
{
GskMatrixTransform *self = (GskMatrixTransform *) transform;
graphene_matrix_t inverse;
if (!graphene_matrix_inverse (&self->matrix, &inverse))
{
gsk_transform_unref (next);
return NULL;
}
return gsk_transform_matrix_with_category (next,
&inverse,
transform->category);
}
static gboolean
gsk_matrix_transform_equal (GskTransform *first_transform,
GskTransform *second_transform)
{
GskMatrixTransform *first = (GskMatrixTransform *) first_transform;
GskMatrixTransform *second = (GskMatrixTransform *) second_transform;
if (graphene_matrix_equal_fast (&first->matrix, &second->matrix))
return TRUE;
return graphene_matrix_equal (&first->matrix, &second->matrix);
}
static const GskTransformClass GSK_TRANSFORM_TRANSFORM_CLASS =
{
sizeof (GskMatrixTransform),
"GskMatrixTransform",
gsk_matrix_transform_finalize,
gsk_matrix_transform_to_matrix,
gsk_matrix_transform_apply_2d,
gsk_matrix_transform_apply_affine,
gsk_matrix_transform_apply_translate,
gsk_matrix_transform_print,
gsk_matrix_transform_apply,
gsk_matrix_transform_invert,
gsk_matrix_transform_equal,
};
static GskTransform *
gsk_transform_matrix_with_category (GskTransform *next,
const graphene_matrix_t *matrix,
GskTransformCategory category)
{
GskMatrixTransform *result = gsk_transform_alloc (&GSK_TRANSFORM_TRANSFORM_CLASS, category, next);
graphene_matrix_init_from_matrix (&result->matrix, matrix);
return &result->parent;
}
/**
* gsk_transform_matrix:
* @next: (nullable) (transfer full): the next transform
* @matrix: the matrix to multiply @next with
*
* Multiplies @next with the given @matrix.
*
* Returns: The new transform
**/
GskTransform *
gsk_transform_matrix (GskTransform *next,
const graphene_matrix_t *matrix)
{
return gsk_transform_matrix_with_category (next, matrix, GSK_TRANSFORM_CATEGORY_UNKNOWN);
}
/* }}} */
/* {{{ TRANSLATE */
typedef struct _GskTranslateTransform GskTranslateTransform;
struct _GskTranslateTransform
{
GskTransform parent;
graphene_point3d_t point;
};
static void
gsk_translate_transform_finalize (GskTransform *self)
{
}
static void
gsk_translate_transform_to_matrix (GskTransform *transform,
graphene_matrix_t *out_matrix)
{
GskTranslateTransform *self = (GskTranslateTransform *) transform;
graphene_matrix_init_translate (out_matrix, &self->point);
}
static void
gsk_translate_transform_apply_2d (GskTransform *transform,
float *out_xx,
float *out_yx,
float *out_xy,
float *out_yy,
float *out_dx,
float *out_dy)
{
GskTranslateTransform *self = (GskTranslateTransform *) transform;
g_assert (self->point.z == 0.0);
*out_dx += *out_xx * self->point.x + *out_xy * self->point.y;
*out_dy += *out_yx * self->point.x + *out_yy * self->point.y;
}
static void
gsk_translate_transform_apply_affine (GskTransform *transform,
float *out_scale_x,
float *out_scale_y,
float *out_dx,
float *out_dy)
{
GskTranslateTransform *self = (GskTranslateTransform *) transform;
g_assert (self->point.z == 0.0);
*out_dx += *out_scale_x * self->point.x;
*out_dy += *out_scale_y * self->point.y;
}
static void
gsk_translate_transform_apply_translate (GskTransform *transform,
float *out_dx,
float *out_dy)
{
GskTranslateTransform *self = (GskTranslateTransform *) transform;
g_assert (self->point.z == 0.0);
*out_dx += self->point.x;
*out_dy += self->point.y;
}
static GskTransform *
gsk_translate_transform_apply (GskTransform *transform,
GskTransform *apply_to)
{
GskTranslateTransform *self = (GskTranslateTransform *) transform;
return gsk_transform_translate_3d (apply_to, &self->point);
}
static GskTransform *
gsk_translate_transform_invert (GskTransform *transform,
GskTransform *next)
{
GskTranslateTransform *self = (GskTranslateTransform *) transform;
return gsk_transform_translate_3d (next, &GRAPHENE_POINT3D_INIT (-self->point.x, -self->point.y, -self->point.z));
}
static gboolean
gsk_translate_transform_equal (GskTransform *first_transform,
GskTransform *second_transform)
{
GskTranslateTransform *first = (GskTranslateTransform *) first_transform;
GskTranslateTransform *second = (GskTranslateTransform *) second_transform;
return G_APPROX_VALUE (first->point.x, second->point.x, FLT_EPSILON) &&
G_APPROX_VALUE (first->point.y, second->point.y, FLT_EPSILON) &&
G_APPROX_VALUE (first->point.z, second->point.z, FLT_EPSILON);
}
static void
gsk_translate_transform_print (GskTransform *transform,
GString *string)
{
GskTranslateTransform *self = (GskTranslateTransform *) transform;
if (self->point.z == 0)
g_string_append (string, "translate(");
else
g_string_append (string, "translate3d(");
string_append_double (string, self->point.x);
g_string_append (string, ", ");
string_append_double (string, self->point.y);
if (self->point.z != 0)
{
g_string_append (string, ", ");
string_append_double (string, self->point.z);
}
g_string_append (string, ")");
}
static const GskTransformClass GSK_TRANSLATE_TRANSFORM_CLASS =
{
sizeof (GskTranslateTransform),
"GskTranslateTransform",
gsk_translate_transform_finalize,
gsk_translate_transform_to_matrix,
gsk_translate_transform_apply_2d,
gsk_translate_transform_apply_affine,
gsk_translate_transform_apply_translate,
gsk_translate_transform_print,
gsk_translate_transform_apply,
gsk_translate_transform_invert,
gsk_translate_transform_equal,
};
/**
* gsk_transform_translate:
* @next: (nullable) (transfer full): the next transform
* @point: the point to translate the transform by
*
* Translates @next in 2-dimensional space by @point.
*
* Returns: (nullable): The new transform
**/
GskTransform *
gsk_transform_translate (GskTransform *next,
const graphene_point_t *point)
{
graphene_point3d_t point3d;
graphene_point3d_init (&point3d, point->x, point->y, 0);
return gsk_transform_translate_3d (next, &point3d);
}
/**
* gsk_transform_translate_3d:
* @next: (nullable) (transfer full): the next transform
* @point: the point to translate the transform by
*
* Translates @next by @point.
*
* Returns: (nullable): The new transform
**/
GskTransform *
gsk_transform_translate_3d (GskTransform *next,
const graphene_point3d_t *point)
{
GskTranslateTransform *result;
if (graphene_point3d_equal (point, graphene_point3d_zero ()))
return next;
if (gsk_transform_has_class (next, &GSK_TRANSLATE_TRANSFORM_CLASS))
{
GskTranslateTransform *t = (GskTranslateTransform *) next;
GskTransform *r = gsk_transform_translate_3d (gsk_transform_ref (next->next),
&GRAPHENE_POINT3D_INIT(t->point.x + point->x,
t->point.y + point->y,
t->point.z + point->z));
gsk_transform_unref (next);
return r;
}
result = gsk_transform_alloc (&GSK_TRANSLATE_TRANSFORM_CLASS,
point->z == 0.0 ? GSK_TRANSFORM_CATEGORY_2D_TRANSLATE
: GSK_TRANSFORM_CATEGORY_3D,
next);
graphene_point3d_init_from_point (&result->point, point);
return &result->parent;
}
/* }}} */
/* {{{ ROTATE */
typedef struct _GskRotateTransform GskRotateTransform;
struct _GskRotateTransform
{
GskTransform parent;
float angle;
};
static void
gsk_rotate_transform_finalize (GskTransform *self)
{
}
static inline void
_sincos (float deg,
float *out_s,
float *out_c)
{
if (deg == 90.0)
{
*out_c = 0.0;
*out_s = 1.0;
}
else if (deg == 180.0)
{
*out_c = -1.0;
*out_s = 0.0;
}
else if (deg == 270.0)
{
*out_c = 0.0;
*out_s = -1.0;
}
else if (deg == 0.0)
{
*out_c = 1.0;
*out_s = 0.0;
}
else
{
float angle = deg * M_PI / 180.0;
#ifdef HAVE_SINCOSF
sincosf (angle, out_s, out_c);
#else
*out_s = sinf (angle);
*out_c = cosf (angle);
#endif
}
}
static void
gsk_rotate_transform_to_matrix (GskTransform *transform,
graphene_matrix_t *out_matrix)
{
GskRotateTransform *self = (GskRotateTransform *) transform;
float c, s;
_sincos (self->angle, &s, &c);
graphene_matrix_init_from_2d (out_matrix,
c, s,
-s, c,
0, 0);
}
static void
gsk_rotate_transform_apply_2d (GskTransform *transform,
float *out_xx,
float *out_yx,
float *out_xy,
float *out_yy,
float *out_dx,
float *out_dy)
{
GskRotateTransform *self = (GskRotateTransform *) transform;
float s, c, xx, xy, yx, yy;
_sincos (self->angle, &s, &c);
xx = c * *out_xx + s * *out_xy;
yx = c * *out_yx + s * *out_yy;
xy = -s * *out_xx + c * *out_xy;
yy = -s * *out_yx + c * *out_yy;
*out_xx = xx;
*out_yx = yx;
*out_xy = xy;
*out_yy = yy;
}
static GskTransform *
gsk_rotate_transform_apply (GskTransform *transform,
GskTransform *apply_to)
{
GskRotateTransform *self = (GskRotateTransform *) transform;
return gsk_transform_rotate (apply_to, self->angle);
}
static GskTransform *
gsk_rotate_transform_invert (GskTransform *transform,
GskTransform *next)
{
GskRotateTransform *self = (GskRotateTransform *) transform;
return gsk_transform_rotate (next, - self->angle);
}
static gboolean
gsk_rotate_transform_equal (GskTransform *first_transform,
GskTransform *second_transform)
{
GskRotateTransform *first = (GskRotateTransform *) first_transform;
GskRotateTransform *second = (GskRotateTransform *) second_transform;
return G_APPROX_VALUE (first->angle, second->angle, 0.01f);
}
static void
gsk_rotate_transform_print (GskTransform *transform,
GString *string)
{
GskRotateTransform *self = (GskRotateTransform *) transform;
g_string_append (string, "rotate(");
string_append_double (string, self->angle);
g_string_append (string, ")");
}
static const GskTransformClass GSK_ROTATE_TRANSFORM_CLASS =
{
sizeof (GskRotateTransform),
"GskRotateTransform",
gsk_rotate_transform_finalize,
gsk_rotate_transform_to_matrix,
gsk_rotate_transform_apply_2d,
NULL,
NULL,
gsk_rotate_transform_print,
gsk_rotate_transform_apply,
gsk_rotate_transform_invert,
gsk_rotate_transform_equal,
};
static inline float
normalize_angle (float angle)
{
if (angle >= 0 && angle < 360)
return angle;
while (angle >= 360)
angle -= 360;
while (angle < 0)
angle += 360;
/* Due to precision issues we may end up with a result that is just
* past the allowed range when rounded. For example, something like
* -epsilon + 360 when rounded to a float may end up with 360.
* So, we handle these cases by returning the exact value 0.
*/
if (angle >= 360)
angle = 0;
g_assert (angle < 360.0);
g_assert (angle >= 0.0);
return angle;
}
/**
* gsk_transform_rotate:
* @next: (nullable) (transfer full): the next transform
* @angle: the rotation angle, in degrees (clockwise)
*
* Rotates @next @angle degrees in 2D - or in 3D-speak, around the Z axis.
* The rotation happens around the origin point of (0, 0).
*
* Returns: (nullable): The new transform
*/
GskTransform *
gsk_transform_rotate (GskTransform *next,
float angle)
{
GskRotateTransform *result;
if (angle == 0.0f)
return next;
if (gsk_transform_has_class (next, &GSK_ROTATE_TRANSFORM_CLASS))
{
GskTransform *r = gsk_transform_rotate (gsk_transform_ref (next->next),
((GskRotateTransform *) next)->angle + angle);
gsk_transform_unref (next);
return r;
}
result = gsk_transform_alloc (&GSK_ROTATE_TRANSFORM_CLASS,
GSK_TRANSFORM_CATEGORY_2D,
next);
result->angle = normalize_angle (angle);
return &result->parent;
}
/* }}} */
/* {{{ ROTATE 3D */
typedef struct _GskRotate3dTransform GskRotate3dTransform;
struct _GskRotate3dTransform
{
GskTransform parent;
float angle;
graphene_vec3_t axis;
};
static void
gsk_rotate3d_transform_finalize (GskTransform *self)
{
}
static void
gsk_rotate3d_transform_to_matrix (GskTransform *transform,
graphene_matrix_t *out_matrix)
{
GskRotate3dTransform *self = (GskRotate3dTransform *) transform;
graphene_matrix_init_rotate (out_matrix, self->angle, &self->axis);
}
static GskTransform *
gsk_rotate3d_transform_apply (GskTransform *transform,
GskTransform *apply_to)
{
GskRotate3dTransform *self = (GskRotate3dTransform *) transform;
return gsk_transform_rotate_3d (apply_to, self->angle, &self->axis);
}
static GskTransform *
gsk_rotate3d_transform_invert (GskTransform *transform,
GskTransform *next)
{
GskRotate3dTransform *self = (GskRotate3dTransform *) transform;
return gsk_transform_rotate_3d (next, - self->angle, &self->axis);
}
static gboolean
gsk_rotate3d_transform_equal (GskTransform *first_transform,
GskTransform *second_transform)
{
GskRotate3dTransform *first = (GskRotate3dTransform *) first_transform;
GskRotate3dTransform *second = (GskRotate3dTransform *) second_transform;
return G_APPROX_VALUE (first->angle, second->angle, 0.01f) &&
graphene_vec3_equal (&first->axis, &second->axis);
}
static void
gsk_rotate3d_transform_print (GskTransform *transform,
GString *string)
{
GskRotate3dTransform *self = (GskRotate3dTransform *) transform;
float f[3];
guint i;
g_string_append (string, "rotate3d(");
graphene_vec3_to_float (&self->axis, f);
for (i = 0; i < 3; i++)
{
string_append_double (string, f[i]);
g_string_append (string, ", ");
}
string_append_double (string, self->angle);
g_string_append (string, ")");
}
static const GskTransformClass GSK_ROTATE3D_TRANSFORM_CLASS =
{
sizeof (GskRotate3dTransform),
"GskRotate3dTransform",
gsk_rotate3d_transform_finalize,
gsk_rotate3d_transform_to_matrix,
NULL,
NULL,
NULL,
gsk_rotate3d_transform_print,
gsk_rotate3d_transform_apply,
gsk_rotate3d_transform_invert,
gsk_rotate3d_transform_equal,
};
/**
* gsk_transform_rotate_3d:
* @next: (nullable) (transfer full): the next transform
* @angle: the rotation angle, in degrees (clockwise)
* @axis: The rotation axis
*
* Rotates @next @angle degrees around @axis.
*
* For a rotation in 2D space, use [method@Gsk.Transform.rotate]
*
* Returns: (nullable): The new transform
*/
GskTransform *
gsk_transform_rotate_3d (GskTransform *next,
float angle,
const graphene_vec3_t *axis)
{
GskRotate3dTransform *result;
if (graphene_vec3_get_x (axis) == 0.0 && graphene_vec3_get_y (axis) == 0.0)
return gsk_transform_rotate (next, angle);
if (angle == 0.0f)
return next;
result = gsk_transform_alloc (&GSK_ROTATE3D_TRANSFORM_CLASS,
GSK_TRANSFORM_CATEGORY_3D,
next);
result->angle = normalize_angle (angle);
graphene_vec3_init_from_vec3 (&result->axis, axis);
return &result->parent;
}
/* }}} */
/* {{{ SKEW */
typedef struct _GskSkewTransform GskSkewTransform;
struct _GskSkewTransform
{
GskTransform parent;
float skew_x;
float skew_y;
};
static void
gsk_skew_transform_finalize (GskTransform *self)
{
}
#define DEG_TO_RAD(x) ((x) / 180.f * G_PI)
#define RAD_TO_DEG(x) ((x) * 180.f / G_PI)
static void
gsk_skew_transform_to_matrix (GskTransform *transform,
graphene_matrix_t *out_matrix)
{
GskSkewTransform *self = (GskSkewTransform *) transform;
graphene_matrix_init_skew (out_matrix,
DEG_TO_RAD (self->skew_x),
DEG_TO_RAD (self->skew_y));
}
static void
gsk_skew_transform_apply_2d (GskTransform *transform,
float *out_xx,
float *out_yx,
float *out_xy,
float *out_yy,
float *out_dx,
float *out_dy)
{
graphene_matrix_t sm, mat;
gsk_skew_transform_to_matrix (transform, &sm);
graphene_matrix_init_from_2d (&mat, *out_xx, *out_yx,
*out_xy, *out_yy,
*out_dx, *out_dy);
graphene_matrix_multiply (&sm, &mat, &mat);
*out_xx = graphene_matrix_get_value (&mat, 0, 0);
*out_yx = graphene_matrix_get_value (&mat, 0, 1);
*out_xy = graphene_matrix_get_value (&mat, 1, 0);
*out_yy = graphene_matrix_get_value (&mat, 1, 1);
*out_dx = graphene_matrix_get_value (&mat, 3, 0);
*out_dy = graphene_matrix_get_value (&mat, 3, 1);
}
static GskTransform *
gsk_skew_transform_apply (GskTransform *transform,
GskTransform *apply_to)
{
GskSkewTransform *self = (GskSkewTransform *) transform;
return gsk_transform_skew (apply_to, self->skew_x, self->skew_y);
}
static void
gsk_skew_transform_print (GskTransform *transform,
GString *string)
{
GskSkewTransform *self = (GskSkewTransform *) transform;
if (self->skew_y == 0)
{
g_string_append (string, "skewX(");
string_append_double (string, self->skew_x);
g_string_append (string, ")");
}
else if (self->skew_x == 0)
{
g_string_append (string, "skewY(");
string_append_double (string, self->skew_y);
g_string_append (string, ")");
}
else
{
g_string_append (string, "skew(");
string_append_double (string, self->skew_x);
g_string_append (string, ", ");
string_append_double (string, self->skew_y);
g_string_append (string, ")");
}
}
static GskTransform *
gsk_skew_transform_invert (GskTransform *transform,
GskTransform *next)
{
GskSkewTransform *self = (GskSkewTransform *) transform;
float tx, ty;
graphene_matrix_t matrix;
tx = tanf (DEG_TO_RAD (self->skew_x));
ty = tanf (DEG_TO_RAD (self->skew_y));
graphene_matrix_init_from_2d (&matrix,
1 / (1 - tx * ty),
- ty / (1 - tx * ty),
- tx / (1 - tx * ty),
1 / (1 - tx * ty),
0, 0);
return gsk_transform_matrix_with_category (next,
&matrix,
GSK_TRANSFORM_CATEGORY_2D);
}
static gboolean
gsk_skew_transform_equal (GskTransform *first_transform,
GskTransform *second_transform)
{
GskSkewTransform *first = (GskSkewTransform *) first_transform;
GskSkewTransform *second = (GskSkewTransform *) second_transform;
return G_APPROX_VALUE (first->skew_x, second->skew_x, FLT_EPSILON) &&
G_APPROX_VALUE (first->skew_y, second->skew_y, FLT_EPSILON);
}
static const GskTransformClass GSK_SKEW_TRANSFORM_CLASS =
{
sizeof (GskSkewTransform),
"GskSkewTransform",
gsk_skew_transform_finalize,
gsk_skew_transform_to_matrix,
gsk_skew_transform_apply_2d,
NULL,
NULL,
gsk_skew_transform_print,
gsk_skew_transform_apply,
gsk_skew_transform_invert,
gsk_skew_transform_equal,
};
/**
* gsk_transform_skew:
* @next: (nullable) (transfer full): the next transform
* @skew_x: skew factor, in degrees, on the X axis
* @skew_y: skew factor, in degrees, on the Y axis
*
* Applies a skew transform.
*
* Returns: (nullable): The new transform
*
* Since: 4.6
*/
GskTransform *
gsk_transform_skew (GskTransform *next,
float skew_x,
float skew_y)
{
GskSkewTransform *result;
if (skew_x == 0 && skew_y == 0)
return next;
result = gsk_transform_alloc (&GSK_SKEW_TRANSFORM_CLASS,
GSK_TRANSFORM_CATEGORY_2D,
next);
result->skew_x = skew_x;
result->skew_y = skew_y;
return &result->parent;
}
/* }}} */
/* {{{ SCALE */
typedef struct _GskScaleTransform GskScaleTransform;
struct _GskScaleTransform
{
GskTransform parent;
float factor_x;
float factor_y;
float factor_z;
};
static void
gsk_scale_transform_finalize (GskTransform *self)
{
}
static void
gsk_scale_transform_to_matrix (GskTransform *transform,
graphene_matrix_t *out_matrix)
{
GskScaleTransform *self = (GskScaleTransform *) transform;
graphene_matrix_init_scale (out_matrix, self->factor_x, self->factor_y, self->factor_z);
}
static void
gsk_scale_transform_apply_2d (GskTransform *transform,
float *out_xx,
float *out_yx,
float *out_xy,
float *out_yy,
float *out_dx,
float *out_dy)
{
GskScaleTransform *self = (GskScaleTransform *) transform;
g_assert (self->factor_z == 1.0);
*out_xx *= self->factor_x;
*out_yx *= self->factor_x;
*out_xy *= self->factor_y;
*out_yy *= self->factor_y;
}
static void
gsk_scale_transform_apply_affine (GskTransform *transform,
float *out_scale_x,
float *out_scale_y,
float *out_dx,
float *out_dy)
{
GskScaleTransform *self = (GskScaleTransform *) transform;
g_assert (self->factor_z == 1.0);
*out_scale_x *= self->factor_x;
*out_scale_y *= self->factor_y;
}
static GskTransform *
gsk_scale_transform_apply (GskTransform *transform,
GskTransform *apply_to)
{
GskScaleTransform *self = (GskScaleTransform *) transform;
return gsk_transform_scale_3d (apply_to, self->factor_x, self->factor_y, self->factor_z);
}
static GskTransform *
gsk_scale_transform_invert (GskTransform *transform,
GskTransform *next)
{
GskScaleTransform *self = (GskScaleTransform *) transform;
return gsk_transform_scale_3d (next,
1.f / self->factor_x,
1.f / self->factor_y,
1.f / self->factor_z);
}
static gboolean
gsk_scale_transform_equal (GskTransform *first_transform,
GskTransform *second_transform)
{
GskScaleTransform *first = (GskScaleTransform *) first_transform;
GskScaleTransform *second = (GskScaleTransform *) second_transform;
return G_APPROX_VALUE (first->factor_x, second->factor_x, FLT_EPSILON) &&
G_APPROX_VALUE (first->factor_y, second->factor_y, FLT_EPSILON) &&
G_APPROX_VALUE (first->factor_z, second->factor_z, FLT_EPSILON);
}
static void
gsk_scale_transform_print (GskTransform *transform,
GString *string)
{
GskScaleTransform *self = (GskScaleTransform *) transform;
if (self->factor_z == 1.0)
{
g_string_append (string, "scale(");
string_append_double (string, self->factor_x);
if (self->factor_x != self->factor_y)
{
g_string_append (string, ", ");
string_append_double (string, self->factor_y);
}
g_string_append (string, ")");
}
else
{
g_string_append (string, "scale3d(");
string_append_double (string, self->factor_x);
g_string_append (string, ", ");
string_append_double (string, self->factor_y);
g_string_append (string, ", ");
string_append_double (string, self->factor_z);
g_string_append (string, ")");
}
}
static const GskTransformClass GSK_SCALE_TRANSFORM_CLASS =
{
sizeof (GskScaleTransform),
"GskScaleTransform",
gsk_scale_transform_finalize,
gsk_scale_transform_to_matrix,
gsk_scale_transform_apply_2d,
gsk_scale_transform_apply_affine,
NULL,
gsk_scale_transform_print,
gsk_scale_transform_apply,
gsk_scale_transform_invert,
gsk_scale_transform_equal,
};
/**
* gsk_transform_scale:
* @next: (nullable) (transfer full): the next transform
* @factor_x: scaling factor on the X axis
* @factor_y: scaling factor on the Y axis
*
* Scales @next in 2-dimensional space by the given factors.
*
* Use [method@Gsk.Transform.scale_3d] to scale in all 3 dimensions.
*
* Returns: (nullable): The new transform
**/
GskTransform *
gsk_transform_scale (GskTransform *next,
float factor_x,
float factor_y)
{
return gsk_transform_scale_3d (next, factor_x, factor_y, 1.0);
}
/**
* gsk_transform_scale_3d:
* @next: (nullable) (transfer full): the next transform
* @factor_x: scaling factor on the X axis
* @factor_y: scaling factor on the Y axis
* @factor_z: scaling factor on the Z axis
*
* Scales @next by the given factors.
*
* Returns: (nullable): The new transform
**/
GskTransform *
gsk_transform_scale_3d (GskTransform *next,
float factor_x,
float factor_y,
float factor_z)
{
GskScaleTransform *result;
if (factor_x == 1 && factor_y == 1 && factor_z == 1)
return next;
if (gsk_transform_has_class (next, &GSK_SCALE_TRANSFORM_CLASS))
{
GskScaleTransform *scale = (GskScaleTransform *) next;
GskTransform *r = gsk_transform_scale_3d (gsk_transform_ref (next->next),
scale->factor_x * factor_x,
scale->factor_y * factor_y,
scale->factor_z * factor_z);
gsk_transform_unref (next);
return r;
}
result = gsk_transform_alloc (&GSK_SCALE_TRANSFORM_CLASS,
factor_z != 1.0 ? GSK_TRANSFORM_CATEGORY_3D
: GSK_TRANSFORM_CATEGORY_2D_AFFINE,
next);
result->factor_x = factor_x;
result->factor_y = factor_y;
result->factor_z = factor_z;
return &result->parent;
}
/* }}} */
/* {{{ PERSPECTIVE */
typedef struct _GskPerspectiveTransform GskPerspectiveTransform;
struct _GskPerspectiveTransform
{
GskTransform parent;
float depth;
};
static void
gsk_perspective_transform_finalize (GskTransform *self)
{
}
static void
gsk_perspective_transform_to_matrix (GskTransform *transform,
graphene_matrix_t *out_matrix)
{
GskPerspectiveTransform *self = (GskPerspectiveTransform *) transform;
float f[16] = { 1.f, 0.f, 0.f, 0.f,
0.f, 1.f, 0.f, 0.f,
0.f, 0.f, 1.f, self->depth ? -1.f / self->depth : 0.f,
0.f, 0.f, 0.f, 1.f };
graphene_matrix_init_from_float (out_matrix, f);
}
static GskTransform *
gsk_perspective_transform_apply (GskTransform *transform,
GskTransform *apply_to)
{
GskPerspectiveTransform *self = (GskPerspectiveTransform *) transform;
return gsk_transform_perspective (apply_to, self->depth);
}
static GskTransform *
gsk_perspective_transform_invert (GskTransform *transform,
GskTransform *next)
{
GskPerspectiveTransform *self = (GskPerspectiveTransform *) transform;
return gsk_transform_perspective (next, - self->depth);
}
static gboolean
gsk_perspective_transform_equal (GskTransform *first_transform,
GskTransform *second_transform)
{
GskPerspectiveTransform *first = (GskPerspectiveTransform *) first_transform;
GskPerspectiveTransform *second = (GskPerspectiveTransform *) second_transform;
return G_APPROX_VALUE (first->depth, second->depth, 0.001f);
}
static void
gsk_perspective_transform_print (GskTransform *transform,
GString *string)
{
GskPerspectiveTransform *self = (GskPerspectiveTransform *) transform;
g_string_append (string, "perspective(");
string_append_double (string, self->depth);
g_string_append (string, ")");
}
static const GskTransformClass GSK_PERSPECTIVE_TRANSFORM_CLASS =
{
sizeof (GskPerspectiveTransform),
"GskPerspectiveTransform",
gsk_perspective_transform_finalize,
gsk_perspective_transform_to_matrix,
NULL,
NULL,
NULL,
gsk_perspective_transform_print,
gsk_perspective_transform_apply,
gsk_perspective_transform_invert,
gsk_perspective_transform_equal,
};
/**
* gsk_transform_perspective:
* @next: (nullable) (transfer full): the next transform
* @depth: distance of the z=0 plane. Lower values give a more
* flattened pyramid and therefore a more pronounced
* perspective effect.
*
* Applies a perspective projection transform.
*
* This transform scales points in X and Y based on their Z value,
* scaling points with positive Z values away from the origin, and
* those with negative Z values towards the origin. Points
* on the z=0 plane are unchanged.
*
* Returns: The new transform
*/
GskTransform *
gsk_transform_perspective (GskTransform *next,
float depth)
{
GskPerspectiveTransform *result;
if (gsk_transform_has_class (next, &GSK_PERSPECTIVE_TRANSFORM_CLASS))
{
GskTransform *r = gsk_transform_perspective (gsk_transform_ref (next->next),
((GskPerspectiveTransform *) next)->depth + depth);
gsk_transform_unref (next);
return r;
}
result = gsk_transform_alloc (&GSK_PERSPECTIVE_TRANSFORM_CLASS,
GSK_TRANSFORM_CATEGORY_ANY,
next);
result->depth = depth;
return &result->parent;
}
/* }}} */
/* {{{ PUBLIC API */
/**
* gsk_transform_ref:
* @self: (nullable): a `GskTransform`
*
* Acquires a reference on the given `GskTransform`.
*
* Returns: (nullable) (transfer none): the `GskTransform` with an additional reference
*/
GskTransform *
gsk_transform_ref (GskTransform *self)
{
if (self == NULL)
return NULL;
return g_atomic_rc_box_acquire (self);
}
/**
* gsk_transform_unref:
* @self: (nullable): a `GskTransform`
*
* Releases a reference on the given `GskTransform`.
*
* If the reference was the last, the resources associated to the @self are
* freed.
*/
void
gsk_transform_unref (GskTransform *self)
{
if (self == NULL)
return;
g_atomic_rc_box_release_full (self, (GDestroyNotify) gsk_transform_finalize);
}
/**
* gsk_transform_print:
* @self: (nullable): a `GskTransform`
* @string: The string to print into
*
* Converts @self into a human-readable string representation suitable
* for printing.
*
* The result of this function can later be parsed with
* [func@Gsk.Transform.parse].
*/
void
gsk_transform_print (GskTransform *self,
GString *string)
{
g_return_if_fail (string != NULL);
if (self == NULL)
{
g_string_append (string, "none");
return;
}
if (self->next != NULL)
{
gsk_transform_print (self->next, string);
g_string_append (string, " ");
}
self->transform_class->print (self, string);
}
/**
* gsk_transform_to_string:
* @self: (nullable): a `GskTransform`
*
* Converts a matrix into a string that is suitable for printing.
*
* The resulting string can be parsed with [func@Gsk.Transform.parse].
*
* This is a wrapper around [method@Gsk.Transform.print].
*
* Returns: A new string for @self
*/
char *
gsk_transform_to_string (GskTransform *self)
{
GString *string;
string = g_string_new ("");
gsk_transform_print (self, string);
return g_string_free (string, FALSE);
}
/**
* gsk_transform_to_matrix:
* @self: (nullable): a `GskTransform`
* @out_matrix: (out caller-allocates): The matrix to set
*
* Computes the actual value of @self and stores it in @out_matrix.
*
* The previous value of @out_matrix will be ignored.
*/
void
gsk_transform_to_matrix (GskTransform *self,
graphene_matrix_t *out_matrix)
{
graphene_matrix_t m;
if (self == NULL)
{
graphene_matrix_init_identity (out_matrix);
return;
}
gsk_transform_to_matrix (self->next, out_matrix);
self->transform_class->to_matrix (self, &m);
graphene_matrix_multiply (&m, out_matrix, out_matrix);
}
/**
* gsk_transform_to_2d:
* @self: a 2D `GskTransform`
* @out_xx: (out): return location for the xx member
* @out_yx: (out): return location for the yx member
* @out_xy: (out): return location for the xy member
* @out_yy: (out): return location for the yy member
* @out_dx: (out): return location for the x0 member
* @out_dy: (out): return location for the y0 member
*
* Converts a `GskTransform` to a 2D transformation matrix.
*
* @self must be a 2D transformation. If you are not
* sure, use gsk_transform_get_category() >=
* %GSK_TRANSFORM_CATEGORY_2D to check.
*
* The returned values have the following layout:
*
* ```
* | xx yx | | a b 0 |
* | xy yy | = | c d 0 |
* | dx dy | | tx ty 1 |
* ```
*
* This function can be used to convert between a `GskTransform`
* and a matrix type from other 2D drawing libraries, in particular
* Cairo.
*/
void
gsk_transform_to_2d (GskTransform *self,
float *out_xx,
float *out_yx,
float *out_xy,
float *out_yy,
float *out_dx,
float *out_dy)
{
*out_xx = 1.0f;
*out_yx = 0.0f;
*out_xy = 0.0f;
*out_yy = 1.0f;
*out_dx = 0.0f;
*out_dy = 0.0f;
if (self == NULL)
return;
if (G_UNLIKELY (self->category < GSK_TRANSFORM_CATEGORY_2D))
{
char *s = gsk_transform_to_string (self);
g_warning ("Given transform \"%s\" is not a 2D transform.", s);
g_free (s);
return;
}
gsk_transform_to_2d (self->next,
out_xx, out_yx,
out_xy, out_yy,
out_dx, out_dy);
self->transform_class->apply_2d (self,
out_xx, out_yx,
out_xy, out_yy,
out_dx, out_dy);
}
/**
* gsk_transform_to_2d_components:
* @self: a `GskTransform`
* @out_skew_x: (out): return location for the skew factor
* in the x direction
* @out_skew_y: (out): return location for the skew factor
* in the y direction
* @out_scale_x: (out): return location for the scale
* factor in the x direction
* @out_scale_y: (out): return location for the scale
* factor in the y direction
* @out_angle: (out): return location for the rotation angle
* @out_dx: (out): return location for the translation
* in the x direction
* @out_dy: (out): return location for the translation
* in the y direction
*
* Converts a `GskTransform` to 2D transformation factors.
*
* To recreate an equivalent transform from the factors returned
* by this function, use
*
* gsk_transform_skew (
* gsk_transform_scale (
* gsk_transform_rotate (
* gsk_transform_translate (NULL, &GRAPHENE_POINT_T (dx, dy)),
* angle),
* scale_x, scale_y),
* skew_x, skew_y)
*
* @self must be a 2D transformation. If you are not sure, use
*
* gsk_transform_get_category() >= %GSK_TRANSFORM_CATEGORY_2D
*
* to check.
*
* Since: 4.6
*/
void
gsk_transform_to_2d_components (GskTransform *self,
float *out_skew_x,
float *out_skew_y,
float *out_scale_x,
float *out_scale_y,
float *out_angle,
float *out_dx,
float *out_dy)
{
float a, b, c, d, e, f;
gsk_transform_to_2d (self, &a, &b, &c, &d, &e, &f);
*out_dx = e;
*out_dy = f;
#define sign(f) ((f) < 0 ? -1 : 1)
if (a != 0 || b != 0)
{
float det = a * d - b * c;
float r = sqrtf (a*a + b*b);
*out_angle = RAD_TO_DEG (sign (b) * acosf (a / r));
*out_scale_x = r;
*out_scale_y = det / r;
*out_skew_x = RAD_TO_DEG (atanf ((a*c + b*d) / (r*r)));
*out_skew_y = 0;
}
else if (c != 0 || d != 0)
{
float det = a * d - b * c;
float s = sqrtf (c*c + d*d);
*out_angle = RAD_TO_DEG (G_PI/2 - sign (d) * acosf (-c / s));
*out_scale_x = det / s;
*out_scale_y = s;
*out_skew_x = 0;
*out_skew_y = RAD_TO_DEG (atanf ((a*c + b*d) / (s*s)));
}
else
{
*out_angle = 0;
*out_scale_x = 0;
*out_scale_y = 0;
*out_skew_x = 0;
*out_skew_y = 0;
}
}
/**
* gsk_transform_to_affine:
* @self: a `GskTransform`
* @out_scale_x: (out): return location for the scale
* factor in the x direction
* @out_scale_y: (out): return location for the scale
* factor in the y direction
* @out_dx: (out): return location for the translation
* in the x direction
* @out_dy: (out): return location for the translation
* in the y direction
*
* Converts a `GskTransform` to 2D affine transformation factors.
*
* To recreate an equivalent transform from the factors returned
* by this function, use
*
* gsk_transform_scale (gsk_transform_translate (NULL,
* &GRAPHENE_POINT_T (dx, dy)),
* sx, sy)
*
* @self must be a 2D affine transformation. If you are not
* sure, use
*
* gsk_transform_get_category() >= %GSK_TRANSFORM_CATEGORY_2D_AFFINE
*
* to check.
*/
void
gsk_transform_to_affine (GskTransform *self,
float *out_scale_x,
float *out_scale_y,
float *out_dx,
float *out_dy)
{
*out_scale_x = 1.0f;
*out_scale_y = 1.0f;
*out_dx = 0.0f;
*out_dy = 0.0f;
if (self == NULL)
return;
if (G_UNLIKELY (self->category < GSK_TRANSFORM_CATEGORY_2D_AFFINE))
{
char *s = gsk_transform_to_string (self);
g_warning ("Given transform \"%s\" is not an affine 2D transform.", s);
g_free (s);
return;
}
gsk_transform_to_affine (self->next,
out_scale_x, out_scale_y,
out_dx, out_dy);
self->transform_class->apply_affine (self,
out_scale_x, out_scale_y,
out_dx, out_dy);
}
/**
* gsk_transform_to_translate:
* @self: a `GskTransform`
* @out_dx: (out): return location for the translation
* in the x direction
* @out_dy: (out): return location for the translation
* in the y direction
*
* Converts a `GskTransform` to a translation operation.
*
* @self must be a 2D transformation. If you are not
* sure, use
*
* gsk_transform_get_category() >= %GSK_TRANSFORM_CATEGORY_2D_TRANSLATE
*
* to check.
*/
void
gsk_transform_to_translate (GskTransform *self,
float *out_dx,
float *out_dy)
{
*out_dx = 0.0f;
*out_dy = 0.0f;
if (self == NULL)
return;
if (G_UNLIKELY (self->category < GSK_TRANSFORM_CATEGORY_2D_TRANSLATE))
{
char *s = gsk_transform_to_string (self);
g_warning ("Given transform \"%s\" is not an affine 2D translation.", s);
g_free (s);
return;
}
gsk_transform_to_translate (self->next, out_dx, out_dy);
self->transform_class->apply_translate (self, out_dx, out_dy);
}
/**
* gsk_transform_transform:
* @next: (nullable) (transfer full): Transform to apply @other to
* @other: (nullable): Transform to apply
*
* Applies all the operations from @other to @next.
*
* Returns: (nullable): The new transform
*/
GskTransform *
gsk_transform_transform (GskTransform *next,
GskTransform *other)
{
if (other == NULL)
return next;
if (next == NULL)
return gsk_transform_ref (other);
if (gsk_transform_is_identity (next))
{
/* ref before unref to avoid catastrophe when other == next */
other = gsk_transform_ref (other);
gsk_transform_unref (next);
return other;
}
next = gsk_transform_transform (next, other->next);
return other->transform_class->apply (other, next);
}
/**
* gsk_transform_invert:
* @self: (nullable) (transfer full): Transform to invert
*
* Inverts the given transform.
*
* If @self is not invertible, %NULL is returned.
* Note that inverting %NULL also returns %NULL, which is
* the correct inverse of %NULL. If you need to differentiate
* between those cases, you should check @self is not %NULL
* before calling this function.
*
* Returns: (nullable): The inverted transform
*/
GskTransform *
gsk_transform_invert (GskTransform *self)
{
GskTransform *result = NULL;
GskTransform *cur;
for (cur = self; cur; cur = cur->next)
{
result = cur->transform_class->invert (cur, result);
if (result == NULL)
break;
}
gsk_transform_unref (self);
return result;
}
/**
* gsk_transform_equal:
* @first: (nullable): the first transform
* @second: (nullable): the second transform
*
* Checks two transforms for equality.
*
* Returns: %TRUE if the two transforms perform the same operation
*/
gboolean
gsk_transform_equal (GskTransform *first,
GskTransform *second)
{
if (first == second)
return TRUE;
if (first == NULL)
return gsk_transform_is_identity (second);
if (second == NULL)
return gsk_transform_is_identity (first);
if (first->transform_class != second->transform_class)
return FALSE;
if (!gsk_transform_equal (first->next, second->next))
return FALSE;
return first->transform_class->equal (first, second);
}
/**
* gsk_transform_get_category:
* @self: (nullable): A `GskTransform`
*
* Returns the category this transform belongs to.
*
* Returns: The category of the transform
**/
GskTransformCategory
(gsk_transform_get_category) (GskTransform *self)
{
if (self == NULL)
return GSK_TRANSFORM_CATEGORY_IDENTITY;
return self->category;
}
/*
* gsk_transform_new: (constructor):
*
* Creates a new identity transform.
*
* This function is meant to be used by language
* bindings. For C code, this is equivalent to using %NULL.
*
* Returns: A new identity transform
*/
GskTransform *
gsk_transform_new (void)
{
return gsk_transform_alloc (&GSK_IDENTITY_TRANSFORM_CLASS, GSK_TRANSFORM_CATEGORY_IDENTITY, NULL);
}
/**
* gsk_transform_transform_bounds:
* @self: a `GskTransform`
* @rect: a `graphene_rect_t`
* @out_rect: (out caller-allocates): return location for the bounds
* of the transformed rectangle
*
* Transforms a `graphene_rect_t` using the given transform @self.
*
* The result is the bounding box containing the coplanar quad.
*/
void
gsk_transform_transform_bounds (GskTransform *self,
const graphene_rect_t *rect,
graphene_rect_t *out_rect)
{
switch (gsk_transform_get_category (self))
{
case GSK_TRANSFORM_CATEGORY_IDENTITY:
graphene_rect_init_from_rect (out_rect, rect);
break;
case GSK_TRANSFORM_CATEGORY_2D_TRANSLATE:
{
float dx, dy;
gsk_transform_to_translate (self, &dx, &dy);
graphene_rect_init (out_rect,
rect->origin.x + dx,
rect->origin.y + dy,
rect->size.width,
rect->size.height);
}
break;
case GSK_TRANSFORM_CATEGORY_2D_AFFINE:
{
float dx, dy, scale_x, scale_y;
gsk_transform_to_affine (self, &scale_x, &scale_y, &dx, &dy);
graphene_rect_init (out_rect,
(rect->origin.x * scale_x) + dx,
(rect->origin.y * scale_y) + dy,
rect->size.width * scale_x,
rect->size.height * scale_y);
}
break;
case GSK_TRANSFORM_CATEGORY_UNKNOWN:
case GSK_TRANSFORM_CATEGORY_ANY:
case GSK_TRANSFORM_CATEGORY_3D:
case GSK_TRANSFORM_CATEGORY_2D:
default:
{
graphene_matrix_t mat;
gsk_transform_to_matrix (self, &mat);
gsk_matrix_transform_bounds (&mat, rect, out_rect);
}
break;
}
}
/**
* gsk_transform_transform_point:
* @self: a `GskTransform`
* @point: a `graphene_point_t`
* @out_point: (out caller-allocates): return location for
* the transformed point
*
* Transforms a `graphene_point_t` using the given transform @self.
*/
void
gsk_transform_transform_point (GskTransform *self,
const graphene_point_t *point,
graphene_point_t *out_point)
{
switch (gsk_transform_get_category (self))
{
case GSK_TRANSFORM_CATEGORY_IDENTITY:
*out_point = *point;
break;
case GSK_TRANSFORM_CATEGORY_2D_TRANSLATE:
{
float dx, dy;
gsk_transform_to_translate (self, &dx, &dy);
out_point->x = point->x + dx;
out_point->y = point->y + dy;
}
break;
case GSK_TRANSFORM_CATEGORY_2D_AFFINE:
{
float dx, dy, scale_x, scale_y;
gsk_transform_to_affine (self, &scale_x, &scale_y, &dx, &dy);
out_point->x = (point->x * scale_x) + dx;
out_point->y = (point->y * scale_y) + dy;
}
break;
case GSK_TRANSFORM_CATEGORY_UNKNOWN:
case GSK_TRANSFORM_CATEGORY_ANY:
case GSK_TRANSFORM_CATEGORY_3D:
case GSK_TRANSFORM_CATEGORY_2D:
default:
{
graphene_matrix_t mat;
gsk_transform_to_matrix (self, &mat);
gsk_matrix_transform_point (&mat, point, out_point);
}
break;
}
}
static guint
gsk_transform_parse_float (GtkCssParser *parser,
guint n,
gpointer data)
{
float *f = data;
double d;
if (!gtk_css_parser_consume_number (parser, &d))
return 0;
f[n] = d;
return 1;
}
static guint
gsk_transform_parse_scale (GtkCssParser *parser,
guint n,
gpointer data)
{
float *f = data;
double d;
if (!gtk_css_parser_consume_number (parser, &d))
return 0;
f[n] = d;
f[1] = d;
return 1;
}
gboolean
gsk_transform_parser_parse (GtkCssParser *parser,
GskTransform **out_transform)
{
const GtkCssToken *token;
GskTransform *transform = NULL;
float f[16] = { 0, };
gboolean parsed_something = FALSE;
token = gtk_css_parser_get_token (parser);
if (gtk_css_token_is_ident (token, "none"))
{
gtk_css_parser_consume_token (parser);
*out_transform = NULL;
return TRUE;
}
while (TRUE)
{
if (gtk_css_token_is_function (token, "matrix"))
{
graphene_matrix_t matrix;
if (!gtk_css_parser_consume_function (parser, 6, 6, gsk_transform_parse_float, f))
goto fail;
graphene_matrix_init_from_2d (&matrix, f[0], f[1], f[2], f[3], f[4], f[5]);
transform = gsk_transform_matrix_with_category (transform,
&matrix,
GSK_TRANSFORM_CATEGORY_2D);
}
else if (gtk_css_token_is_function (token, "matrix3d"))
{
graphene_matrix_t matrix;
if (!gtk_css_parser_consume_function (parser, 16, 16, gsk_transform_parse_float, f))
goto fail;
graphene_matrix_init_from_float (&matrix, f);
transform = gsk_transform_matrix (transform, &matrix);
}
else if (gtk_css_token_is_function (token, "perspective"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_perspective (transform, f[0]);
}
else if (gtk_css_token_is_function (token, "rotate") ||
gtk_css_token_is_function (token, "rotateZ"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_rotate (transform, f[0]);
}
else if (gtk_css_token_is_function (token, "rotate3d"))
{
graphene_vec3_t axis;
if (!gtk_css_parser_consume_function (parser, 4, 4, gsk_transform_parse_float, f))
goto fail;
graphene_vec3_init (&axis, f[0], f[1], f[2]);
transform = gsk_transform_rotate_3d (transform, f[3], &axis);
}
else if (gtk_css_token_is_function (token, "rotateX"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_rotate_3d (transform, f[0], graphene_vec3_x_axis ());
}
else if (gtk_css_token_is_function (token, "rotateY"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_rotate_3d (transform, f[0], graphene_vec3_y_axis ());
}
else if (gtk_css_token_is_function (token, "scale"))
{
if (!gtk_css_parser_consume_function (parser, 1, 2, gsk_transform_parse_scale, f))
goto fail;
transform = gsk_transform_scale (transform, f[0], f[1]);
}
else if (gtk_css_token_is_function (token, "scale3d"))
{
if (!gtk_css_parser_consume_function (parser, 3, 3, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_scale_3d (transform, f[0], f[1], f[2]);
}
else if (gtk_css_token_is_function (token, "scaleX"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_scale (transform, f[0], 1.f);
}
else if (gtk_css_token_is_function (token, "scaleY"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_scale (transform, 1.f, f[0]);
}
else if (gtk_css_token_is_function (token, "scaleZ"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_scale_3d (transform, 1.f, 1.f, f[0]);
}
else if (gtk_css_token_is_function (token, "translate"))
{
f[1] = 0.f;
if (!gtk_css_parser_consume_function (parser, 1, 2, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_translate (transform, &GRAPHENE_POINT_INIT (f[0], f[1]));
}
else if (gtk_css_token_is_function (token, "translate3d"))
{
if (!gtk_css_parser_consume_function (parser, 3, 3, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_translate_3d (transform, &GRAPHENE_POINT3D_INIT (f[0], f[1], f[2]));
}
else if (gtk_css_token_is_function (token, "translateX"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_translate (transform, &GRAPHENE_POINT_INIT (f[0], 0.f));
}
else if (gtk_css_token_is_function (token, "translateY"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_translate (transform, &GRAPHENE_POINT_INIT (0.f, f[0]));
}
else if (gtk_css_token_is_function (token, "translateZ"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_translate_3d (transform, &GRAPHENE_POINT3D_INIT (0.f, 0.f, f[0]));
}
else if (gtk_css_token_is_function (token, "skew"))
{
if (!gtk_css_parser_consume_function (parser, 2, 2, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_skew (transform, f[0], f[1]);
}
else if (gtk_css_token_is_function (token, "skewX"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_skew (transform, f[0], 0);
}
else if (gtk_css_token_is_function (token, "skewY"))
{
if (!gtk_css_parser_consume_function (parser, 1, 1, gsk_transform_parse_float, f))
goto fail;
transform = gsk_transform_skew (transform, 0, f[0]);
}
else
{
break;
}
parsed_something = TRUE;
token = gtk_css_parser_get_token (parser);
}
if (!parsed_something)
{
gtk_css_parser_error_syntax (parser, "Expected a transform");
goto fail;
}
*out_transform = transform;
return TRUE;
fail:
gsk_transform_unref (transform);
*out_transform = NULL;
return FALSE;
}
/**
* gsk_transform_parse:
* @string: the string to parse
* @out_transform: (out): The location to put the transform in
*
* Parses the given @string into a transform and puts it in
* @out_transform.
*
* Strings printed via [method@Gsk.Transform.to_string]
* can be read in again successfully using this function.
*
* If @string does not describe a valid transform, %FALSE is
* returned and %NULL is put in @out_transform.
*
* Returns: %TRUE if @string described a valid transform.
*/
gboolean
gsk_transform_parse (const char *string,
GskTransform **out_transform)
{
GtkCssParser *parser;
GBytes *bytes;
gboolean result;
g_return_val_if_fail (string != NULL, FALSE);
g_return_val_if_fail (out_transform != NULL, FALSE);
bytes = g_bytes_new_static (string, strlen (string));
parser = gtk_css_parser_new_for_bytes (bytes, NULL, NULL, NULL, NULL);
result = gsk_transform_parser_parse (parser, out_transform);
if (result && !gtk_css_parser_has_token (parser, GTK_CSS_TOKEN_EOF))
{
g_clear_pointer (out_transform, gsk_transform_unref);
result = FALSE;
}
gtk_css_parser_unref (parser);
g_bytes_unref (bytes);
return result;
}
/* Some of the graphene_matrix_transform apis yield unexpected
* results with projective matrices, since they silently drop
* the w component, so we provide working alternatives here.
*/
void
gsk_matrix_transform_point (const graphene_matrix_t *m,
const graphene_point_t *p,
graphene_point_t *res)
{
graphene_vec4_t vec4;
float w;
graphene_vec4_init (&vec4, p->x, p->y, 0.0f, 1.0f);
graphene_matrix_transform_vec4 (m, &vec4, &vec4);
w = graphene_vec4_get_w (&vec4);
res->x = graphene_vec4_get_x (&vec4) / w;
res->y = graphene_vec4_get_y (&vec4) / w;
}
void
gsk_matrix_transform_point3d (const graphene_matrix_t *m,
const graphene_point3d_t *p,
graphene_point3d_t *res)
{
graphene_vec4_t vec4;
float w;
graphene_vec4_init (&vec4, p->x, p->y, 0.0f, 1.0f);
graphene_matrix_transform_vec4 (m, &vec4, &vec4);
w = graphene_vec4_get_w (&vec4);
res->x = graphene_vec4_get_x (&vec4) / w;
res->y = graphene_vec4_get_y (&vec4) / w;
res->z = graphene_vec4_get_z (&vec4) / w;
}
void
gsk_matrix_transform_rect (const graphene_matrix_t *m,
const graphene_rect_t *r,
graphene_quad_t *res)
{
graphene_point_t ret[4];
graphene_rect_t rr;
graphene_rect_normalize_r (r, &rr);
#define TRANSFORM_POINT(matrix, rect, corner, out_p) do {\
graphene_vec4_t __s; \
graphene_point_t __p; \
float w; \
graphene_rect_get_ ## corner (rect, &__p); \
graphene_vec4_init (&__s, __p.x, __p.y, 0.f, 1.f); \
graphene_matrix_transform_vec4 (matrix, &__s, &__s); \
w = graphene_vec4_get_w (&__s); \
out_p.x = graphene_vec4_get_x (&__s) / w; \
out_p.y = graphene_vec4_get_y (&__s) / w; } while (0)
TRANSFORM_POINT (m, &rr, top_left, ret[0]);
TRANSFORM_POINT (m, &rr, top_right, ret[1]);
TRANSFORM_POINT (m, &rr, bottom_right, ret[2]);
TRANSFORM_POINT (m, &rr, bottom_left, ret[3]);
#undef TRANSFORM_POINT
graphene_quad_init (res, &ret[0], &ret[1], &ret[2], &ret[3]);
}
void
gsk_matrix_transform_bounds (const graphene_matrix_t *m,
const graphene_rect_t *r,
graphene_rect_t *res)
{
graphene_quad_t q;
gsk_matrix_transform_rect (m, r, &q);
graphene_quad_bounds (&q, res);
}
/* }}} */
/* vim:set foldmethod=marker expandtab: */
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