rectangle: Added routines to get each point in a rectangle

diff --git a/src/rectangle.s b/src/rectangle.s
index 3e188481dd2e91c9909fefe76fa0068209f205b8..63c458093307cbbc486137e6d06fc442d859bfbb 100644 (file)
--- a/src/rectangle.s
+++ b/src/rectangle.s
@@ -80,38 +80,93 @@ rect_find_slot:
        ld hl, 0
        ret
        
-       ; tests if any point
-       ; of r1 is inside r2
+
+       ; gets top left of a rectangle
        ; inputs:
-       ;               de: r1
-       ;               hl: r2
+       ;               hl: rectangle
        ;       returns:
-       ;               a == 1: inside
-       ;               a == 0: not inside
-rect_test:
-       ld a, [de]
-       ld b, a
+       ;               de: y/x
+rect_tl:
+       inc hl ; skip mask
+       ld a, [hl+]
+       ld d, a ; d = y
+       ld a, [hl+]
+       ld e, a ; e = x
+
        ld a, [hl]
-       ; check if masks have a match
-       ; otherwise skip
-       and a, b
-       cp a, 0
-       jp z, @no_collision_mask_match
+       ld l, a
+       ld a, d
+       sub a, l ; y-height
+       ld d, a ; d = top left y
+       ret
        
+       ; same as rect_tl
+       ; bototm left
+rect_bl:
+       inc hl ; skip mask
+       ld a, [hl+]
+       ld d, a ; d = y
+       ld a, [hl] 
+       ld e, a ; e = x
        ret
-@no_collision_mask_match:
-       ld a, 0
+       
+       ; same as rect_tl
+       ; top right
+rect_tr:
+       inc hl ; skip mask
+       ld a, [hl+]
+       ld d, a ; d = y
+       ld a, [hl+]
+       ld e, a ; e = x
+       inc hl ; skip height
+
+       ld a, [hl]
+       add a, e ; e = x + width
+       ld e, a 
+
+       dec hl ; go back to height
+       ld a, [hl]
+       ld l, a
+       ld a, d
+       sub a, l ; y-height
+       ld d, a ; d = top right y
        ret
        
+       ; same as rect_tl
+       ; bottom right
+rect_br:
+       inc hl ; skip mask
+       ld a, [hl+]
+       ld d, a ; d = y
+       ld a, [hl+]
+       ld e, a ; e = x
+       inc hl ; skip height
+
+       ld a, [hl]
+       add a, e ; e = x + width
+       ld e, a 
+       ret
+
        ; tests if a point is inside r1
+       ;                a: mask
        ;               bc: y/x point
        ;               hl: rectangle
        ;       returns:
        ;               a == 1: inside
        ;               a == 0: not inside
 rect_point_test:
-       ret
+       ; check collision mask
+       ld d, a
+       ld [hl], a
+       and a, d
+       ; exit if mask is no match
+       jp z, @no_collision_mask_match
+       
 
+       ret
+@no_collision_mask_match:
+       xor a, a
+       ret
        
        ; removes a rectangle
        ; inputs: