diff options
Diffstat (limited to 'gsk')
| -rw-r--r-- | gsk/gsktransform.c | 114 | ||||
| -rw-r--r-- | gsk/gsktransform.h | 3 |
2 files changed, 117 insertions, 0 deletions
diff --git a/gsk/gsktransform.c b/gsk/gsktransform.c index b434d4cb31..a4da1cfad3 100644 --- a/gsk/gsktransform.c +++ b/gsk/gsktransform.c @@ -1095,6 +1095,120 @@ gsk_transform_scale_3d (GskTransform *next, 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, -1.f / self->depth, + 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 first->depth == second->depth; +} + +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: (allow-none): 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 matrix + **/ +GskTransform * +gsk_transform_perspective (GskTransform *next, + float depth) +{ + GskPerspectiveTransform *result; + + result = gsk_transform_alloc (&GSK_PERSPECTIVE_TRANSFORM_CLASS, + GSK_TRANSFORM_CATEGORY_ANY, + next); + + result->depth = depth; + + return &result->parent; +} + /*** PUBLIC API ***/ static void diff --git a/gsk/gsktransform.h b/gsk/gsktransform.h index 19552a0add..6cbe3659f2 100644 --- a/gsk/gsktransform.h +++ b/gsk/gsktransform.h @@ -105,6 +105,9 @@ GskTransform * gsk_transform_scale_3d (GskTransform float factor_x, float factor_y, float factor_z); +GDK_AVAILABLE_IN_ALL +GskTransform * gsk_transform_perspective (GskTransform *next, + float depth); GDK_AVAILABLE_IN_ALL void gsk_transform_transform_bounds (GskTransform *self, |