2 ; Graphics driver for the 160x102x16 mode on the Lynx.
4 ; All the drawing functions are simply done by sprites as the sprite
5 ; engine is the only way to do fast graphics on a Lynx.
7 ; So the code is not really based on any algorithms done by somebody.
8 ; I have looked at other routines in the cc65 libs to see what kind of
9 ; entry points we need. And I have looked at the old cc65 libs by
10 ; Bastian Schick to see how things worked in the past.
12 ; This code is written by Karri Kaksonen, 2004 for the cc65 compiler.
15 .include "zeropage.inc"
18 .include "tgi-kernel.inc"
19 .include "tgi-mode.inc"
20 .include "tgi-error.inc"
26 ; ------------------------------------------------------------------------
27 ; Header. Includes jump table and constants.
31 ; First part of the header is a structure that has a magic and defines the
32 ; capabilities of the driver
34 .byte $74, $67, $69 ; "tgi"
35 .byte TGI_API_VERSION ; TGI API version number
36 .word 160 ; X resolution
37 .word 102 ; Y resolution
38 .byte 16 ; Number of drawing colors
39 .byte 2 ; Number of screens available
40 .byte 8 ; System font X size
41 .byte 8 ; System font Y size
42 .res 4, $00 ; Reserved for future extensions
44 ; Next comes the jump table. Currently all entries must be valid and may point
45 ; to an RTS for test versions (function not implemented). A future version may
46 ; allow for emulation: In this case the vector will be zero. Emulation means
47 ; that the graphics kernel will emulate the function by using lower level
48 ; primitives - for example ploting a line by using calls to SETPIXEL.
70 .addr 0 ; IRQ entry is unused
73 ; ------------------------------------------------------------------------
76 ; Variables mapped to the zero page segment variables. Some of these are
77 ; used for passing parameters to the driver.
89 ; Absolute variables used in the code
93 ERROR: .res 1 ; Error code
95 DRAWINDEX: .res 1 ; Pen to use for drawing
105 BGINDEX: .res 1 ; Pen to use for text background
107 text_bitmap: .res 8*(1+20+1)+1
108 ; 8 rows with (one offset-byte plus 20 character bytes plus one fill-byte) plus one 0-offset-byte
110 ; Constants and tables
114 DEFPALETTE: .byte >$000
147 PALETTESIZE = * - DEFPALETTE
151 ; ------------------------------------------------------------------------
152 ; INSTALL routine. Is called after the driver is loaded into memory. May
153 ; initialize anything that has to be done just once. Is probably empty
156 ; Must set an error code: NO
167 ; ------------------------------------------------------------------------
168 ; UNINSTALL routine. Is called before the driver is removed from memory. May
169 ; clean up anything done by INSTALL but is probably empty most of the time.
171 ; Must set an error code: NO
178 ; ------------------------------------------------------------------------
179 ; INIT: Changes an already installed device from text mode to graphics
181 ; Note that INIT/DONE may be called multiple times while the driver
182 ; is loaded, while INSTALL is only called once, so any code that is needed
183 ; to initializes variables and so on must go here. Setting palette and
184 ; clearing the screen is not needed because this is called by the graphics
186 ; The graphics kernel will never call INIT when a graphics mode is already
187 ; active, so there is no need to protect against that.
189 ; Must set an error code: YES
193 ; Done, reset the error code
198 ; ------------------------------------------------------------------------
199 ; DONE: Will be called to switch the graphics device back into text mode.
200 ; The graphics kernel will never call DONE when no graphics mode is active,
201 ; so there is no need to protect against that.
203 ; Must set an error code: NO
209 ; ------------------------------------------------------------------------
210 ; GETERROR: Return the error code in A and clear it.
218 ; ------------------------------------------------------------------------
219 ; CONTROL: Platform/driver specific entry point.
221 ; Must set an error code: YES
223 ; The TGI lacks a way to draw sprites. As that functionality is vital to
224 ; Lynx games we borrow this CONTROL function to implement the still
225 ; missing tgi_draw_sprite funtion. To use this in your C-program
226 ; do a #define tgi_draw_sprite(spr) tgi_ioctl(0, spr)
228 ; To do a flip-screen call tgi_ioctl(1, 0)
230 ; To set the background index for text outputs call tgi_ioctl(2, bgindex)
270 lda ptr1 ; Get the sprite address
273 draw_sprite: ; Draw it in render buffer
292 ; ------------------------------------------------------------------------
293 ; CLEAR: Clears the screen.
295 ; Must set an error code: NO
300 .byte 3,%10000100,%00000000, $0 ; A pixel bitmap
302 .byte %00000001 ; A pixel sprite
313 CLEAR: lda #<cls_sprite
317 ; ------------------------------------------------------------------------
318 ; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
319 ; The page number is already checked to be valid by the graphics kernel.
321 ; Must set an error code: NO (will only be called if page ok)
323 ; It is a good idea to call this function during the vertical blanking
324 ; period. If you call it in the middle of the screen update then half of
325 ; the drawn frame will be from the old buffer and the other half is
326 ; from the new buffer. This is usually noticed by the user.
330 beq @L1 ; page == maxpages-1
338 sty VIEWPAGEL ; Save viewpage for getpixel
341 lda __viddma ; Process flipped displays
356 ; ------------------------------------------------------------------------
357 ; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
358 ; The page number is already checked to be valid by the graphics kernel.
360 ; Must set an error code: NO (will only be called if page ok)
365 beq @L1 ; page == maxpages-1
377 ; ------------------------------------------------------------------------
378 ; SETCOLOR: Set the drawing color (in A). The new color is already checked
379 ; to be in a valid range (0..maxcolor-1).
381 ; Must set an error code: NO (will only be called if color ok)
388 ; ------------------------------------------------------------------------
389 ; SETPALETTE: Set the palette (not available with all drivers/hardware).
390 ; A pointer to the palette is passed in ptr1. Must set an error if palettes
393 ; Must set an error code: YES
399 sta GCOLMAP,y ; $FDA0
403 ; Done, reset the error code
409 ; ------------------------------------------------------------------------
410 ; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
411 ; set the palette should return the default palette here, so there's no
412 ; way for this function to fail.
414 ; Must set an error code: NO
418 lda #<GCOLMAP ; $FDA0
422 ; ------------------------------------------------------------------------
423 ; GETDEFPALETTE: Return the default palette for the driver in A/X. All
424 ; drivers should return something reasonable here, even drivers that don't
425 ; support palettes, otherwise the caller has no way to determine the colors
426 ; of the (not changeable) palette.
428 ; Must set an error code: NO (all drivers must have a default palette)
436 ; ------------------------------------------------------------------------
437 ; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
438 ; color. The coordinates passed to this function are never outside the
439 ; visible screen area, so there is no need for clipping inside this function.
441 ; Must set an error code: NO
446 .byte %00000001 ; A pixel sprite
468 ; ------------------------------------------------------------------------
469 ; GETPIXEL: Read the color value of a pixel and return it in A/X. The
470 ; coordinates passed to this function are never outside the visible screen
471 ; area, so there is no need for clipping inside this function.
476 sta MATHD ; Hardware multiply
513 ; ------------------------------------------------------------------------
514 ; LINE: Draw a line from X1/Y1 to X2/Y2, where X1/Y1 = ptr1/ptr2 and
515 ; X2/Y2 = ptr3/ptr4 using the current drawing color.
517 ; Must set an error code: NO
522 .byte 0 ; Will be replaced by the code
570 lda #%00000000 ; Not flipped
588 lda #%00010000 ; Vertical flip
603 sta MATHP ; hardware divide
616 bmi @L3 ; wait for math done (bit 7 of sprsys)
636 ; ------------------------------------------------------------------------
637 ; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
638 ; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
639 ; Contrary to most other functions, the graphics kernel will sort and clip
640 ; the coordinates before calling the driver, so on entry the following
641 ; conditions are valid:
644 ; (X1 >= 0) && (X1 < XRES)
645 ; (X2 >= 0) && (X2 < XRES)
646 ; (Y1 >= 0) && (Y1 < YRES)
647 ; (Y2 >= 0) && (Y2 < YRES)
649 ; Must set an error code: NO
654 .byte %00000001 ; A pixel sprite
685 ; ------------------------------------------------------------------------
686 ; CIRCLE: Draw a circle around the center X1/Y1 (= ptr1/ptr2) with the
687 ; radius in tmp1 and the current drawing color.
689 ; Must set an error code: NO
691 ; There is no sensible way of drawing a circle on a Lynx. As I would
692 ; have to use line elements to do the circle I rather do it in C than
693 ; create it here in the driver.
695 ; To do a circle please add this to your C program
699 ; 3196, // 11.25 degrees
700 ; 6270, // 22.5 degrees
701 ; 9102, // 33.75 degrees
702 ; 11585, // 45 degrees
703 ; 13623, // 56.25 degrees
704 ; 15137, // 67.5 degrees
705 ; 16069, // 78.75 degrees
706 ; 16384 // 90 degrees
723 ;void tgi_Circle(int x0, int y0, unsigned char r)
726 ; int x1, y1, x2, y2;
728 ; x1 = ((long)sin(0) * r + 8192) / 16384 + x0;
729 ; y1 = ((long)sin(8) * r + 8192) / 16384 + y0;
730 ; for (i = 1; i <= 32; i++) {
731 ; x2 = ((long)sin(i) * r + 8192) / 16384 + x0;
732 ; y2 = ((long)sin(i+8) * r + 8192) / 16384 + y0;
733 ; tgi_line(x1, y1, x2, y2);
739 ;#define tgi_circle tgi_Circle
744 ; ------------------------------------------------------------------------
745 ; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
746 ; direction is passend in X/Y, the text direction is passed in A.
748 ; Must set an error code: NO
757 ; ------------------------------------------------------------------------
758 ; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
759 ; current text style. The text to output is given as a zero terminated
760 ; string with address in ptr3.
762 ; Must set an error code: NO
766 lda TEXTMAGX ; Scale sprite
771 stz text_sprite ; Set normal sprite
775 sta text_sprite ; Set opaque sprite
777 lda DRAWINDEX ; Set color
785 lda X1 ; Set start position
794 ldy #-1 ; Calculate string length
805 rts ; Zero length string
807 iny ; Prepare text_bitmap
811 ldy #8-1 ; 8 pixel lines per character
848 ; and now copy the 8 bytes of that char
854 ; draw char from top to bottom, reading char-data from offset 8-1 to offset 0
857 lda (FONTOFF),y ; *chptr
858 sta text_bitmap,x ;textbuf[y*(1+len+1)+1+x]
894 ; 96 characters from ASCII 32 to 127
895 ; 8 pixels wide, 8 pixels high
896 ; bit value 0 = foreground, bit value 1 = background / transparent
899 .byte $FF, $FF, $FF, $FF, $FF, $FF, $FF, $FF ;32
900 .byte $FF, $E7, $FF, $FF, $E7, $E7, $E7, $E7 ;33
901 .byte $FF, $FF, $FF, $FF, $FF, $99, $99, $99 ;34
902 .byte $FF, $99, $99, $00, $99, $00, $99, $99 ;35
903 .byte $FF, $E7, $83, $F9, $C3, $9F, $C1, $E7 ;36
904 .byte $FF, $B9, $99, $CF, $E7, $F3, $99, $9D ;37
905 .byte $FF, $C0, $99, $98, $C7, $C3, $99, $C3 ;38
906 .byte $FF, $FF, $FF, $FF, $FF, $E7, $F3, $F9 ;39
907 .byte $FF, $F3, $E7, $CF, $CF, $CF, $E7, $F3 ;40
908 .byte $FF, $CF, $E7, $F3, $F3, $F3, $E7, $CF ;41
909 .byte $FF, $FF, $99, $C3, $00, $C3, $99, $FF ;42
910 .byte $FF, $FF, $E7, $E7, $81, $E7, $E7, $FF ;43
911 .byte $CF, $E7, $E7, $FF, $FF, $FF, $FF, $FF ;44
912 .byte $FF, $FF, $FF, $FF, $81, $FF, $FF, $FF ;45
913 .byte $FF, $E7, $E7, $FF, $FF, $FF, $FF, $FF ;46
914 .byte $FF, $9F, $CF, $E7, $F3, $F9, $FC, $FF ;47
915 .byte $FF, $C3, $99, $99, $89, $91, $99, $C3 ;48
916 .byte $FF, $81, $E7, $E7, $E7, $C7, $E7, $E7 ;49
917 .byte $FF, $81, $9F, $CF, $F3, $F9, $99, $C3 ;50
918 .byte $FF, $C3, $99, $F9, $E3, $F9, $99, $C3 ;51
919 .byte $FF, $F9, $F9, $80, $99, $E1, $F1, $F9 ;52
920 .byte $FF, $C3, $99, $F9, $F9, $83, $9F, $81 ;53
921 .byte $FF, $C3, $99, $99, $83, $9F, $99, $C3 ;54
922 .byte $FF, $E7, $E7, $E7, $E7, $F3, $99, $81 ;55
923 .byte $FF, $C3, $99, $99, $C3, $99, $99, $C3 ;56
924 .byte $FF, $C3, $99, $F9, $C1, $99, $99, $C3 ;57
925 .byte $FF, $FF, $E7, $FF, $FF, $E7, $FF, $FF ;58
926 .byte $CF, $E7, $E7, $FF, $FF, $E7, $FF, $FF ;59
927 .byte $FF, $F1, $E7, $CF, $9F, $CF, $E7, $F1 ;60
928 .byte $FF, $FF, $FF, $81, $FF, $81, $FF, $FF ;61
929 .byte $FF, $8F, $E7, $F3, $F9, $F3, $E7, $8F ;62
930 .byte $FF, $E7, $FF, $E7, $F3, $F9, $99, $C3 ;63
933 .byte $FF, $C3, $9D, $9F, $91, $91, $99, $C3 ;0
934 .byte $FF, $99, $99, $99, $81, $99, $C3, $E7 ;1
935 .byte $FF, $83, $99, $99, $83, $99, $99, $83 ;2
936 .byte $FF, $C3, $99, $9F, $9F, $9F, $99, $C3 ;3
937 .byte $FF, $87, $93, $99, $99, $99, $93, $87 ;4
938 .byte $FF, $81, $9F, $9F, $87, $9F, $9F, $81 ;5
939 .byte $FF, $9F, $9F, $9F, $87, $9F, $9F, $81 ;6
940 .byte $FF, $C3, $99, $99, $91, $9F, $99, $C3 ;7
941 .byte $FF, $99, $99, $99, $81, $99, $99, $99 ;8
942 .byte $FF, $C3, $E7, $E7, $E7, $E7, $E7, $C3 ;9
943 .byte $FF, $C7, $93, $F3, $F3, $F3, $F3, $E1 ;10
944 .byte $FF, $99, $93, $87, $8F, $87, $93, $99 ;11
945 .byte $FF, $81, $9F, $9F, $9F, $9F, $9F, $9F ;12
946 .byte $FF, $9C, $9C, $9C, $94, $80, $88, $9C ;13
947 .byte $FF, $99, $99, $91, $81, $81, $89, $99 ;14
948 .byte $FF, $C3, $99, $99, $99, $99, $99, $C3 ;15
949 .byte $FF, $9F, $9F, $9F, $83, $99, $99, $83 ;16
950 .byte $FF, $F1, $C3, $99, $99, $99, $99, $C3 ;17
951 .byte $FF, $99, $93, $87, $83, $99, $99, $83 ;18
952 .byte $FF, $C3, $99, $F9, $C3, $9F, $99, $C3 ;19
953 .byte $FF, $E7, $E7, $E7, $E7, $E7, $E7, $81 ;20
954 .byte $FF, $C3, $99, $99, $99, $99, $99, $99 ;21
955 .byte $FF, $E7, $C3, $99, $99, $99, $99, $99 ;22
956 .byte $FF, $9C, $88, $80, $94, $9C, $9C, $9C ;23
957 .byte $FF, $99, $99, $C3, $E7, $C3, $99, $99 ;24
958 .byte $FF, $E7, $E7, $E7, $C3, $99, $99, $99 ;25
959 .byte $FF, $81, $9F, $CF, $E7, $F3, $F9, $81 ;26
960 .byte $FF, $C3, $CF, $CF, $CF, $CF, $CF, $C3 ;27
961 .byte $FF, $03, $9D, $CF, $83, $CF, $ED, $F3 ;28
962 .byte $FF, $C3, $F3, $F3, $F3, $F3, $F3, $C3 ;29
963 .byte $E7, $E7, $E7, $E7, $81, $C3, $E7, $FF ;30
964 .byte $FF, $EF, $CF, $80, $80, $CF, $EF, $FF ;31
968 .byte $FF, $C3, $9D, $9F, $91, $91, $99, $C3 ;224
969 .byte $FF, $C1, $99, $C1, $F9, $C3, $FF, $FF ;225
970 .byte $FF, $83, $99, $99, $83, $9F, $9F, $FF ;226
971 .byte $FF, $C3, $9F, $9F, $9F, $C3, $FF, $FF ;227
972 .byte $FF, $C1, $99, $99, $C1, $F9, $F9, $FF ;228
973 .byte $FF, $C3, $9F, $81, $99, $C3, $FF, $FF ;229
974 .byte $FF, $E7, $E7, $E7, $C1, $E7, $F1, $FF ;230
975 .byte $83, $F9, $C1, $99, $99, $C1, $FF, $FF ;231
976 .byte $FF, $99, $99, $99, $83, $9F, $9F, $FF ;232
977 .byte $FF, $C3, $E7, $E7, $C7, $FF, $E7, $FF ;233
978 .byte $C3, $F9, $F9, $F9, $F9, $FF, $F9, $FF ;234
979 .byte $FF, $99, $93, $87, $93, $9F, $9F, $FF ;235
980 .byte $FF, $C3, $E7, $E7, $E7, $E7, $C7, $FF ;236
981 .byte $FF, $9C, $94, $80, $80, $99, $FF, $FF ;237
982 .byte $FF, $99, $99, $99, $99, $83, $FF, $FF ;238
983 .byte $FF, $C3, $99, $99, $99, $C3, $FF, $FF ;239
984 .byte $9F, $9F, $83, $99, $99, $83, $FF, $FF ;240
985 .byte $F9, $F9, $C1, $99, $99, $C1, $FF, $FF ;241
986 .byte $FF, $9F, $9F, $9F, $99, $83, $FF, $FF ;242
987 .byte $FF, $83, $F9, $C3, $9F, $C1, $FF, $FF ;243
988 .byte $FF, $F1, $E7, $E7, $E7, $81, $E7, $FF ;244
989 .byte $FF, $C1, $99, $99, $99, $99, $FF, $FF ;245
990 .byte $FF, $E7, $C3, $99, $99, $99, $FF, $FF ;246
991 .byte $FF, $C9, $C1, $80, $94, $9C, $FF, $FF ;247
992 .byte $FF, $99, $C3, $E7, $C3, $99, $FF, $FF ;248
993 .byte $87, $F3, $C1, $99, $99, $99, $FF, $FF ;249
994 .byte $FF, $81, $CF, $E7, $F3, $81, $FF, $FF ;250
995 .byte $FF, $C3, $CF, $CF, $CF, $CF, $CF, $C3 ;251
996 .byte $FF, $03, $9D, $CF, $83, $CF, $ED, $F3 ;252
997 .byte $FF, $C3, $F3, $F3, $F3, $F3, $F3, $C3 ;253
998 .byte $E7, $E7, $E7, $E7, $81, $C3, $E7, $FF ;254
999 .byte $FF, $EF, $CF, $80, $80, $CF, $EF, $FF ;255