darnit_bbox.h

DARNIT_BBOX

a DARNIT_BBOX is a statically allocated list of bounding boxes. These can quickly be matched against an area, with a list of bounding boxes overlapping that area being returned.

• DARNIT_BBOX *d_bbox_new( unsigned int size);
• DARNIT_BBOX *d_bbox_free(DARNIT_BBOX *bbox);
• int d_bbox_test(DARNIT_BBOX *bbox, int x, int y, unsigned int w, unsigned int h, unsigned int *list, unsigned int listlen);
• int d_bbox_add(DARNIT_BBOX *bbox, unsigned int x, unsigned int y, unsigned int w, unsigned int h);
• void d_bbox_delete(DARNIT_BBOX *bbox, int key);
• void d_bbox_move(DARNIT_BBOX *bbox, int key, unsigned int x, unsigned int y);
• void d_bbox_resize(DARNIT_BBOX *bbox, int key, unsigned int w, unsigned int h);
• void d_bbox_clear(DARNIT_BBOX *bbox);

d_bbox_new

DARNIT_BBOX *d_bbox_new(unsigned int size);

Returns a list with space for size bounding boxes.

Arguments

• size - Number of bounding boxes to allocate space for

Return value

NULL on failure. Something else is a valid bounding box list.

d_bbox_free

DARNIT_BBOX *d_bbox_free(DARNIT_BBOX *bbox);

Frees a list of bounding boxes and returns a NULL-pointer.

Arguments

• bbox - A valid list of bounding boxes

Return value

• A NULL-pointer. Provided for compact NULL-ing of the pointer that used to point to the list.

d_bbox_test

int d_bbox_test(DARNIT_BBOX *bbox, int x, int y, unsigned int w, unsigned int h, unsigned int *list, unsigned int listlen);

Tests for bounding boxes in the specified area and fills the array list with index values for the matching boxes.

Arguments

• bbox - the list of bounding boxes to test
• x - the x-coordinate of the area to test
• y - the y-coordinate of the area to test
• w - the width of the area to test
• h - the height of the area to test
• list - An array of indices for matching bounding boxes
• listlen - The size of the array (maximum amount of matches to return)

Illustration

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Return value

Returns the number of matching bounding boxes that was written to the array

d_bbox_add

int d_bbox_add(DARNIT_BBOX *bbox, unsigned int x, unsigned int y, unsigned int w, unsigned int h);

Adds a bounding box to a list of bounding boxes

Arguments

• bbox - The bounding box list to add a bounding box to
• x - The x coordinate that the bounding box have
• y - The y coordinate that the bounding box have
• w - The width of the bounding box to add
• h - The height of the bounding box to add

Return value

Returns the index for the bounding box just added. When the bounding box is matched in a test, this is the index you'll get. Returns -1 if the list is full.

d_bbox_delete

void d_bbox_delete(DARNIT_BBOX *bbox, int key);

Deletes a bounding box from the provided list.

Arguments

• bbox - The bounding box list to delete a bounding box from
• key - Index of the bounding box to delete

Return value None

d_bbox_move

void d_bbox_move(DARNIT_BBOX *bbox, int key, unsigned int x, unsigned int y);

Sets the x and y coordinates of a bounding box without affecting its size.

Arguments

• bbox - The bounding box list to move a bounding box in
• key - Index of the bounding box to move
• x - New x coordinate for the bounding box
• y - New y coordinate for the bounding box

Return value None

d_bbox_resize

void d_bbox_resize(DARNIT_BBOX *bbox, int key, unsigned int w, unsigned int h);

Resizes a bounding box without changing its origin coordinates

Arguments

• bbox - The bounding box list to resize a bounding box in
• key - Index of the bounding box to resize
• w - New width of the bounding box
• h - New height of the bounding box

Return value None

d_bbox_clear

void d_bbox_clear(DARNIT_BBOX *bbox);

Clears a bounding box list from all bounding boxes

Arguments

• bbox - The bounding box list to clear

Return value None