added Cx16 highresbitmap example. added stippled drawing to gfx2 monochrome mode

compiler/res/prog8lib/cx16/gfx2.p8

@@ -6,7 +6,6 @@
 ; Note: for compatible graphics code that words on C64 too, use the "graphics" module instead.
 ; Note: there is no color palette manipulation here, you have to do that yourself or use the "palette" module.
 
-; TODO this is in development.  Add line drawing, circles and discs (like the graphics module has)
 
 gfx2 {
 
@@ -15,6 +14,7 @@ gfx2 {
     uword width = 0
     uword height = 0
     ubyte bpp = 0
+    ubyte monochrome_dont_stipple_flag = false            ; set to false to enable stippling mode in monochrome displaymodes
 
     sub screen_mode(ubyte mode) {
         ; mode 0 = bitmap 320 x 240 x 1c monochrome
@@ -77,6 +77,7 @@ gfx2 {
     }
 
     sub clear_screen() {
+        monochrome_stipple(false)
         position(0, 0)
         when active_mode {
             0 -> {
@@ -98,6 +99,10 @@ gfx2 {
         position(0, 0)
     }
 
+    sub monochrome_stipple(ubyte enable) {
+        monochrome_dont_stipple_flag = ~enable
+    }
+
     sub rect(uword x, uword y, uword width, uword height, ubyte color) {
         if width==0 or height==0
             return
@@ -289,8 +294,8 @@ gfx2 {
         word @zp decisionOver2 = (1 as word)-radius
 
         while radius>=yy {
-            horizontal_line(xcenter-radius, ycenter+yy, radius*2+1, color)
+            horizontal_line(xcenter-radius, ycenter+yy, radius*$0002+1, color)
-            horizontal_line(xcenter-radius, ycenter-yy, radius*2+1, color)
+            horizontal_line(xcenter-radius, ycenter-yy, radius*$0002+1, color)
             horizontal_line(xcenter-yy, ycenter+radius, yy*2+1, color)
             horizontal_line(xcenter-yy, ycenter-radius, yy*2+1, color)
             yy++
@@ -307,26 +312,53 @@ gfx2 {
         ubyte[8] bits = [128, 64, 32, 16, 8, 4, 2, 1]
         uword addr
         ubyte value
+
         when active_mode {
             0 -> {
-                addr = x/8 + y*(320/8)
+                %asm {{
-                value = bits[lsb(x)&7]
+                    lda  x
-                cx16.vpoke_or(0, addr, value)
+                    eor  y
+                    ora  monochrome_dont_stipple_flag
+                    and  #1
+                }}
+                if_nz {
+                    addr = x/8 + y*(320/8)
+                    value = bits[lsb(x)&7]
+                    if color
+                        cx16.vpoke_or(0, addr, value)
+                    else {
+                        value = ~value
+                        cx16.vpoke_and(0, addr, value)
+                    }
+                }
             }
             128 -> {
-                addr = x/8 + y*(640/8)
+                %asm {{
-                value = bits[lsb(x)&7]
+                    lda  x
-                cx16.vpoke_or(0, addr, value)
+                    eor  y
+                    ora  monochrome_dont_stipple_flag
+                    and  #1
+                }}
+                if_nz {
+                    addr = x/8 + y*(640/8)
+                    value = bits[lsb(x)&7]
+                    if color
+                        cx16.vpoke_or(0, addr, value)
+                    else {
+                        value = ~value
+                        cx16.vpoke_and(0, addr, value)
+                    }
+                }
             }
             1 -> {
                 void addr_mul_320_add_24(y, x)      ; 24 bits result is in r0 and r1L
                 value = lsb(cx16.r1)
                 cx16.vpoke(value, cx16.r0, color)
+                ; 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
             }
         }
-        ; 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 @zp x, uword y) {
@@ -424,10 +456,18 @@ gfx2 {
                         lda  cx16.VERA_ADDR_H
                         and  #%111              ; don't auto-increment, we have to do that manually because of the ora
                         sta  cx16.VERA_ADDR_H
+                        lda  color
+                        sta  P8ZP_SCRATCH_B1
                         ldy  #8
--                       lda  cx16.VERA_DATA0
+-                       lda  P8ZP_SCRATCH_B1
+                        bne  +                  ; white color, plot normally
+                        lda  cx16.VERA_DATA1
+                        eor  #255               ; black color, keep only the other pixels
+                        and  cx16.VERA_DATA0
+                        bra  ++
++                       lda  cx16.VERA_DATA0
                         ora  cx16.VERA_DATA1
-                        sta  cx16.VERA_DATA0
++                       sta  cx16.VERA_DATA0
                         lda  cx16.VERA_ADDR_L
                         clc
                         adc  cx16.r2

docs/source/libraries.rst

@@ -91,10 +91,11 @@ gfx2  (cx16 only)
 Full-screen multicolor bitmap graphics routines, available on the Cx16 machine only.
 
 - multiple full-screen resolutions: 640 * 480 monochrome, and 320 * 240 monochrome and 256 colors
-- clearing screen, switching screen mode
+- clearing screen, switching screen mode, also back to text mode is possible.
-- drawing pixels
+- drawing individual pixels
+- drawing lines, rectangles, filled rectangles, circles, discs
 - drawing text inside the bitmap
-- lines, rectangles, circles, discs.
+- in monochrome mode, it's possible to use a stippled drawing pattern to simulate a shade of gray.
 
 
 palette  (cx16 only)

docs/source/todo.rst

@@ -2,7 +2,8 @@
 TODO
 ====
 
-- implement gfx2's rect, fillrect, horizontal_line and vertical_line in graphics modules as well.
+- nice error msg for float as for loop var
+- implement gfx2's rect, fillrect, horizontal_line and vertical_line in graphics modules as well. (and optimize bresenham line to use vert/horiz line if possible)
 - detect variables that are written but never read - mark those as unused too and remove them, such as uword unused = memory("unused222", 20) - also remove the memory slab allocation
 - hoist all variable declarations up to the subroutine scope *before* even the constant folding takes place (to avoid undefined symbol errors when referring to a variable from another nested scope in the subroutine)
 - make it possible to use cpu opcodes such as 'nop' as variable names by prefixing all asm vars with something such as '_'

examples/cx16/highresbitmap.p8

@@ -0,0 +1,87 @@
+%target cx16
+%import gfx2
+%import floats
+%import textio
+%zeropage basicsafe
+
+main {
+
+    sub start () {
+        gfx2.text_charset(3)
+
+        test_monochrome()
+
+        gfx2.screen_mode(255)
+        txt.print("done!\n")
+    }
+
+    sub test_monochrome() {
+        gfx2.screen_mode(128)
+        uword yy
+        uword xx
+        word ww
+
+        yy = 20
+        xx = 20
+        gfx2.monochrome_stipple(false)
+        gfx2.rect(xx, yy, 250, 80, 1)
+        gfx2.monochrome_stipple(true)
+        gfx2.fillrect(xx+2, yy+2, 250-4, 80-4, 1)
+        gfx2.monochrome_stipple(false)
+        gfx2.fillrect(xx+20, yy+20, 200, 30, 1)
+        gfx2.rect(xx+21, yy+21, 200-2, 30-2, 0)
+
+        gfx2.text(xx+30, yy+32, 0, @"High Res Bitmap Example")
+
+        ; gfx2.monochrome_stipple(true)
+        gfx2.horizontal_line(10, 240, 620, 1)
+        gfx2.vertical_line(320, 10, 460, 1)
+        gfx2.text(320, 242, 1, @"0,0")
+        gfx2.text(322, 10, 1, @"Y-axis")
+        gfx2.text(590, 242, 1, @"X-axis")
+        for ww in -10 to 10 {
+            xx = (ww*30) + 320 as uword
+            gfx2.vertical_line(xx, 239, 3, 1)
+        }
+        for ww in -7 to 7 {
+            yy = (ww*30) + 240 as uword
+            gfx2.horizontal_line(319, yy, 3, 1)
+        }
+
+        gfx2.monochrome_stipple(false)
+        float y_f
+        for ww in -600 to 600 {
+            y_f = sin(ww as float / 60.0)*150
+            gfx2.plot(ww/2 + 320 as uword, (y_f + 240) as uword, 1)
+        }
+        gfx2.text(480, 100, 1, @"sin(x)")
+
+        for ww in -300 to 300 {
+            y_f = cos(ww as float/30.0)*60 - (ww as float)/1.7
+            gfx2.plot(ww + 320 as uword, (y_f + 240) as uword, 1)
+        }
+        gfx2.text(80, 420, 1, @"cos(x)+x")
+
+        cx16.wait(3*60)
+
+        gfx2.circle(320, 240, 220, 1)
+        gfx2.circle(320, 240, 210, 1)
+        gfx2.circle(320, 240, 200, 1)
+        gfx2.circle(320, 240, 190, 1)
+        gfx2.monochrome_stipple(true)
+        gfx2.disc(320, 240, 140, 1)
+        gfx2.monochrome_stipple(false)
+        gfx2.disc(320, 240, 90, 1)
+        gfx2.disc(320, 240, 40, 0)
+
+        cx16.wait(2*60)
+
+        repeat 255 {
+            xx=rndw() % 640     ; TODO doesn't work correctly, truncates
+            yy=rndw() % 480     ; TODO doesn't work correctly, truncates
+            gfx2.line(xx, yy, rndw() % 640, rndw() % 480, 1)
+        }
+
+        cx16.wait(1*60)
+    }
+}

examples/test.p8

@@ -7,46 +7,17 @@ main {
 
 
     sub start () {
-        uword length
-        uword total = 0
 
-        length=200
+        ; TODO uword var = rndw() % 640 doesn't work???   works if its in an expression.
-        count()
-        txt.print_uw(total)
-        txt.chrout('\n')
-        length=255
-        count()
-        txt.print_uw(total)
-        txt.chrout('\n')
-        length=256
-        count()
-        txt.print_uw(total)
-        txt.chrout('\n')
-        length=257
-        count()
-        txt.print_uw(total)
-        txt.chrout('\n')
-        length=9999
-        count()
-        txt.print_uw(total)
-        txt.chrout('\n')
 
-        test_stack.test()
+        x_f = -300.0
-
+        for ww in -300 to 300 {
-
+            ;fl = ww as float / 10.0         ; TODO doesn't work???
-        sub count() {
+            y_f = cos(x_f/30)*60 - x_f/1.7
-            total = 0
+            gfx2.plot(ww + 320 as uword, (y_f + 240) as uword, 1)
-            if length>256 {
+            x_f += 1.0
-                repeat length-1
-                    total++
-            } else {
-                uword total2
-                repeat lsb(length-1)
-                    total++
-;                repeat (length-1) as ubyte      ; TODO lsb(length-1) doesn't work!?!?!?
-;                    total++
-            }
         }
+
     }