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adding circle and disc to gfx2

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This commit is contained in:
Irmen de Jong 2020-12-27 15:14:44 +01:00
parent ffffcdd50a
commit cdcda27d07
2 changed files with 95 additions and 25 deletions
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81
compiler/res/prog8lib/cx16/gfx2.p8
View File

@ -98,6 +98,86 @@ gfx2 {
position(0, 0)
}
sub horizontal_line(uword x, uword y, ubyte length, ubyte color) {
when active_mode {
1 -> {
; 8bpp mode
gfx2.plot(x, y, color)
repeat length-1
gfx2.next_pixel(color)
}
0, 128 -> {
; 1 bpp mode
; TODO optimize this to plot 8 pixels at once while possible
repeat length {
gfx2.plot(x, y, color)
x++
}
}
}
}
sub circle(uword xcenter, uword ycenter, ubyte radius, ubyte color) {
; Midpoint algorithm.
ubyte @zp xx = radius
ubyte @zp yy = 0
word @zp decisionOver2 = (1 as word)-xx
; R14 = internal plot X
; R15 = internal plot Y
while xx>=yy {
cx16.r14 = xcenter + xx
cx16.r15 = ycenter + yy
plot(cx16.r14, cx16.r15, color)
cx16.r14 = xcenter - xx
plot(cx16.r14, cx16.r15, color)
cx16.r14 = xcenter + xx
cx16.r15 = ycenter - yy
plot(cx16.r14, cx16.r15, color)
cx16.r14 = xcenter - xx
plot(cx16.r14, cx16.r15, color)
cx16.r14 = xcenter + yy
cx16.r15 = ycenter + xx
plot(cx16.r14, cx16.r15, color)
cx16.r14 = xcenter - yy
plot(cx16.r14, cx16.r15, color)
cx16.r14 = xcenter + yy
cx16.r15 = ycenter - xx
plot(cx16.r14, cx16.r15, color)
cx16.r14 = xcenter - yy
plot(cx16.r14, cx16.r15, color)
yy++
if decisionOver2<=0
decisionOver2 += (yy as word)*2+1
else {
xx--
decisionOver2 += (yy as word -xx)*2+1
}
}
}
sub disc(uword xcenter, uword ycenter, ubyte radius, ubyte color) {
; Midpoint algorithm, filled
ubyte @zp xx = radius
ubyte @zp yy = 0
word @zp decisionOver2 = (1 as word)-xx
while xx>=yy {
horizontal_line(xcenter-xx, ycenter+yy, xx*2+1, color)
horizontal_line(xcenter-xx, ycenter-yy, xx*2+1, color)
horizontal_line(xcenter-yy, ycenter+xx, yy*2+1, color)
horizontal_line(xcenter-yy, ycenter-xx, yy*2+1, color)
yy++
if decisionOver2<=0
decisionOver2 += (yy as word)*2+1
else {
xx--
decisionOver2 += (yy as word -xx)*2+1
}
}
}
sub plot(uword x, uword y, ubyte color) {
ubyte[8] bits = [128, 64, 32, 16, 8, 4, 2, 1]
uword addr
@ -121,6 +201,7 @@ gfx2 {
}
; activate vera auto-increment mode so next_pixel() can be used after this
cx16.VERA_ADDR_H = (cx16.VERA_ADDR_H & %00000111) | %00010000
color = cx16.VERA_DATA0
}
sub position(uword x, uword y) {

39
examples/cx16/testgfx2.p8
View File

@ -8,7 +8,7 @@ main {
sub start () {
gfx2.text_charset(3)
ubyte[] modes = [0, 1, 128]
ubyte[] modes = [1, 0, 128]
ubyte mode
for mode in modes {
gfx2.screen_mode(mode)
@ -17,36 +17,25 @@ main {
for tp in 0 to 15 {
gfx2.text(19+tp,20+tp*11, 5, @"ScreenCODE text! 1234![]<>#$%&*()")
}
cx16.wait(120)
cx16.wait(200)
}
gfx2.screen_mode(255)
txt.print("done!\n")
}
sub draw() {
uword offset
ubyte angle
uword x
uword y
when gfx2.active_mode {
0, 1 -> {
for offset in 0 to 90 step 3 {
for angle in 0 to 255 {
x = $0008+sin8u(angle)/2
y = $0008+cos8u(angle)/2
gfx2.plot(x+offset*2,y+offset, lsb(x+y))
}
}
}
128 -> {
for offset in 0 to 190 step 6 {
for angle in 0 to 255 {
x = $0008+sin8u(angle)
y = $0008+cos8u(angle)
gfx2.plot(x+offset*2,y+offset, 1)
}
}
}
ubyte radius
for radius in 110 downto 8 step -4 {
gfx2.circle(gfx2.width/2, (gfx2.height/2 as ubyte), radius, radius)
}
gfx2.disc(gfx2.width/2, gfx2.height/2, 108, 255)
}
}
gfx3 {
}