Clipping

Clipping — Fuctions for manipulating a stack of clipping regions

Synopsis

void                cogl_clip_push_rectangle            (float x0,
                                                         float y0,
                                                         float x1,
                                                         float y1);
void                cogl_clip_push_window_rectangle     (int x_offset,
                                                         int y_offset,
                                                         int width,
                                                         int height);
void                cogl_clip_push_from_path            (void);
void                cogl_clip_push_from_path_preserve   (void);
void                cogl_clip_pop                       (void);

Description

To support clipping your geometry to rectangles or paths Cogl exposes a stack based API whereby each clip region you push onto the stack is intersected with the previous region.

Details

cogl_clip_push_rectangle ()

void                cogl_clip_push_rectangle            (float x0,
                                                         float y0,
                                                         float x1,
                                                         float y1);

Specifies a rectangular clipping area for all subsequent drawing operations. Any drawing commands that extend outside the rectangle will be clipped so that only the portion inside the rectangle will be displayed. The rectangle dimensions are transformed by the current model-view matrix.

The rectangle is intersected with the current clip region. To undo the effect of this function, call cogl_clip_pop().

x0 :

x coordinate for top left corner of the clip rectangle

y0 :

y coordinate for top left corner of the clip rectangle

x1 :

x coordinate for bottom right corner of the clip rectangle

y1 :

y coordinate for bottom right corner of the clip rectangle

Since 1.2


cogl_clip_push_window_rectangle ()

void                cogl_clip_push_window_rectangle     (int x_offset,
                                                         int y_offset,
                                                         int width,
                                                         int height);

Specifies a rectangular clipping area for all subsequent drawing operations. Any drawing commands that extend outside the rectangle will be clipped so that only the portion inside the rectangle will be displayed. The rectangle dimensions are not transformed by the current model-view matrix.

The rectangle is intersected with the current clip region. To undo the effect of this function, call cogl_clip_pop().

x_offset :

left edge of the clip rectangle in window coordinates

y_offset :

top edge of the clip rectangle in window coordinates

width :

width of the clip rectangle

height :

height of the clip rectangle

Since 1.2


cogl_clip_push_from_path ()

void                cogl_clip_push_from_path            (void);

Sets a new clipping area using the current path. The current path is then cleared. The clipping area is intersected with the previous clipping area. To restore the previous clipping area, call cogl_clip_pop().

Since 1.0


cogl_clip_push_from_path_preserve ()

void                cogl_clip_push_from_path_preserve   (void);

Sets a new clipping area using the current path. The current path is then cleared. The clipping area is intersected with the previous clipping area. To restore the previous clipping area, call cogl_clip_pop().

Since 1.0


cogl_clip_pop ()

void                cogl_clip_pop                       (void);

Reverts the clipping region to the state before the last call to cogl_clip_push().