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added gfx2.safe_vertical_line, gfx2.safe_rect, gfx2.safe_fillrect for completeness

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Irmen de Jong 2024-10-30 18:17:16 +01:00
parent eeeb8d81f4
commit 66b06d6c40
1 changed files with 58 additions and 0 deletions
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58
compiler/res/prog8lib/cx16/gfx2.p8
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@ -128,6 +128,18 @@ gfx2 {
vertical_line(xx+rwidth-1, yy+1, rheight-2, color)
}
sub safe_rect(uword xx, uword yy, uword rwidth, uword rheight, ubyte color) {
; does bounds checking and clipping
safe_horizontal_line(xx, yy, rwidth, color)
if rheight==1
return
safe_horizontal_line(xx, yy+rheight-1, rwidth, color)
safe_vertical_line(xx, yy+1, rheight-2, color)
if rwidth==1
return
safe_vertical_line(xx+rwidth-1, yy+1, rheight-2, color)
}
sub fillrect(uword xx, uword yy, uword rwidth, uword rheight, ubyte color) {
; Draw a filled rectangle of the given size and color.
; To fill the whole screen, use clear_screen(color) instead - it is much faster.
@ -139,6 +151,34 @@ gfx2 {
}
}
sub safe_fillrect(uword xx, uword yy, uword rwidth, uword rheight, ubyte color) {
; Draw a filled rectangle of the given size and color.
; To fill the whole screen, use clear_screen(color) instead - it is much faster.
; This safe version does bounds checking and clipping.
if xx>=width or yy>=width
return
if msb(xx)&$80!=0 {
rwidth += xx
xx = 0
}
if xx>=width
return
if xx+rwidth>width
rwidth = width-xx
if rwidth>width
return
if yy + rheight > height
rheight = height-yy
if rheight>height
return
repeat rheight {
horizontal_line(xx, yy, rwidth, color)
yy++
}
}
sub horizontal_line(uword xx, uword yy, uword length, ubyte color) {
if length==0
return
@ -285,6 +325,24 @@ gfx2 {
}
sub safe_vertical_line(uword xx, uword yy, uword lheight, ubyte color) {
; does bounds checking and clipping
if msb(yy)&$80!=0 or yy>=height
return
if msb(xx)&$80!=0 or xx>=width
return
if msb(yy)&$80!=0 {
lheight += yy
yy = 0
}
if yy+lheight>height
lheight = height-yy
if lheight>height
return
vertical_line(xx, yy, lheight, color)
}
sub line(uword @zp x1, uword @zp y1, uword @zp x2, uword @zp y2, ubyte color) {
; Bresenham algorithm.
; This code special-cases various quadrant loops to allow simple ++ and -- operations.