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.
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 ; Double buffer IRQ stuff
112 text_bitmap: .res 8*(1+20+1)+1
113 ; 8 rows with (one offset-byte plus 20 character bytes plus one fill-byte) plus one 0-offset-byte
115 ; Constants and tables
119 DEFPALETTE: .byte >$000
152 PALETTESIZE = * - DEFPALETTE
156 ; ------------------------------------------------------------------------
157 ; INSTALL routine. Is called after the driver is loaded into memory. May
158 ; initialize anything that has to be done just once. Is probably empty
161 ; Must set an error code: NO
171 lda #$60 ; rts op-code
176 ; ------------------------------------------------------------------------
177 ; UNINSTALL routine. Is called before the driver is removed from memory. May
178 ; clean up anything done by INSTALL but is probably empty most of the time.
180 ; Must set an error code: NO
187 ; ------------------------------------------------------------------------
188 ; INIT: Changes an already installed device from text mode to graphics
190 ; Note that INIT/DONE may be called multiple times while the driver
191 ; is loaded, while INSTALL is only called once, so any code that is needed
192 ; to initializes variables and so on must go here. Setting palette and
193 ; clearing the screen is not needed because this is called by the graphics
195 ; The graphics kernel will never call INIT when a graphics mode is already
196 ; active, so there is no need to protect against that.
198 ; Must set an error code: YES
202 ; Done, reset the error code
207 ; ------------------------------------------------------------------------
208 ; DONE: Will be called to switch the graphics device back into text mode.
209 ; The graphics kernel will never call DONE when no graphics mode is active,
210 ; so there is no need to protect against that.
212 ; Must set an error code: NO
218 ; ------------------------------------------------------------------------
219 ; GETERROR: Return the error code in A and clear it.
227 ; ------------------------------------------------------------------------
228 ; CONTROL: Platform/driver specific entry point.
230 ; Must set an error code: YES
232 ; The TGI lacks a way to draw sprites. As that functionality is vital to
233 ; Lynx games we borrow this CONTROL function to implement the still
234 ; missing tgi_draw_sprite funtion. To use this in your C-program
235 ; do a #define tgi_draw_sprite(spr) tgi_ioctl(0, spr)
237 ; To do a flip-screen call tgi_ioctl(1, 0)
239 ; To set the background index for text outputs call tgi_ioctl(2, bgindex)
241 ; To set the frame rate for the display hardware call tgi_ioctl(3, rate)
243 ; To check if the drawing engine is busy with the previous swap you can
244 ; call tgi_ioctl(4, 0). It returns 0 if idle and 1 if busy
246 ; To update displays you can call tgi_ioctl(4, 1) it will wait for the
247 ; next VBL interrupt and swap draw and view buffers.
249 ; Set an address for a subroutine you want to call at every VBL
253 pha ; Almost all control routines succeed
258 bne ControlSwapRequest
260 lda ptr1 ; Set IRQ routine to be called at VBL
264 lda #$43 ; jmp op-code
272 lda ptr1 ; Swap request
283 cmp #75 ; Set framerate
292 rate50: lda #$bd ; 50 Hz
295 rate60: lda #$9e ; 60 Hz
298 rate75: lda #$7e ; 75 Hz
307 bne ControlFlipScreen
309 lda ptr1 ; Set text background color
315 bne ControlDrawSprite
317 lda __sprsys ; Flip screen
342 lda ptr1 ; Get the sprite address
345 draw_sprite: ; Draw it in render buffer
364 ; ------------------------------------------------------------------------
365 ; CLEAR: Clears the screen.
367 ; Must set an error code: NO
372 .byte 3,%10000100,%00000000, $0 ; A pixel bitmap
374 .byte %00000001 ; A pixel sprite
385 CLEAR: lda #<cls_sprite
389 ; ------------------------------------------------------------------------
390 ; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
391 ; The page number is already checked to be valid by the graphics kernel.
393 ; Must set an error code: NO (will only be called if page ok)
395 ; It is a good idea to call this function during the vertical blanking
396 ; period. If you call it in the middle of the screen update then half of
397 ; the drawn frame will be from the old buffer and the other half is
398 ; from the new buffer. This is usually noticed by the user.
402 beq @L1 ; page == maxpages-1
410 sty VIEWPAGEL ; Save viewpage for getpixel
413 lda __viddma ; Process flipped displays
428 ; ------------------------------------------------------------------------
429 ; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
430 ; The page number is already checked to be valid by the graphics kernel.
432 ; Must set an error code: NO (will only be called if page ok)
437 beq @L1 ; page == maxpages-1
449 ; ------------------------------------------------------------------------
450 ; IRQ: VBL interrupt handler
453 TIMER0_INTERRUPT = $01
454 TIMER1_INTERRUPT = $02
455 TIMER2_INTERRUPT = $04
456 TIMER3_INTERRUPT = $08
457 TIMER4_INTERRUPT = $10
458 TIMER5_INTERRUPT = $20
459 TIMER6_INTERRUPT = $40
460 TIMER7_INTERRUPT = $80
462 HBL_INTERRUPT = TIMER0_INTERRUPT
463 VBL_INTERRUPT = TIMER2_INTERRUPT
464 SERIAL_INTERRUPT = TIMER4_INTERRUPT
467 lda INTSET ; Poll all pending interrupts
470 clc ; Not a VBL interrupt - exit
487 ; ------------------------------------------------------------------------
488 ; SETCOLOR: Set the drawing color (in A). The new color is already checked
489 ; to be in a valid range (0..maxcolor-1).
491 ; Must set an error code: NO (will only be called if color ok)
498 ; ------------------------------------------------------------------------
499 ; SETPALETTE: Set the palette (not available with all drivers/hardware).
500 ; A pointer to the palette is passed in ptr1. Must set an error if palettes
503 ; Must set an error code: YES
509 sta GCOLMAP,y ; $FDA0
513 ; Done, reset the error code
519 ; ------------------------------------------------------------------------
520 ; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
521 ; set the palette should return the default palette here, so there's no
522 ; way for this function to fail.
524 ; Must set an error code: NO
528 lda #<GCOLMAP ; $FDA0
532 ; ------------------------------------------------------------------------
533 ; GETDEFPALETTE: Return the default palette for the driver in A/X. All
534 ; drivers should return something reasonable here, even drivers that don't
535 ; support palettes, otherwise the caller has no way to determine the colors
536 ; of the (not changeable) palette.
538 ; Must set an error code: NO (all drivers must have a default palette)
546 ; ------------------------------------------------------------------------
547 ; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
548 ; color. The coordinates passed to this function are never outside the
549 ; visible screen area, so there is no need for clipping inside this function.
551 ; Must set an error code: NO
556 .byte %00000001 ; A pixel sprite
578 ; ------------------------------------------------------------------------
579 ; GETPIXEL: Read the color value of a pixel and return it in A/X. The
580 ; coordinates passed to this function are never outside the visible screen
581 ; area, so there is no need for clipping inside this function.
586 sta MATHD ; Hardware multiply
623 ; ------------------------------------------------------------------------
624 ; LINE: Draw a line from X1/Y1 to X2/Y2, where X1/Y1 = ptr1/ptr2 and
625 ; X2/Y2 = ptr3/ptr4 using the current drawing color.
627 ; Must set an error code: NO
632 .byte 0 ; Will be replaced by the code
680 lda #%00000000 ; Not flipped
698 lda #%00010000 ; Vertical flip
713 sta MATHP ; hardware divide
726 bmi @L3 ; wait for math done (bit 7 of sprsys)
746 ; ------------------------------------------------------------------------
747 ; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
748 ; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
749 ; Contrary to most other functions, the graphics kernel will sort and clip
750 ; the coordinates before calling the driver, so on entry the following
751 ; conditions are valid:
754 ; (X1 >= 0) && (X1 < XRES)
755 ; (X2 >= 0) && (X2 < XRES)
756 ; (Y1 >= 0) && (Y1 < YRES)
757 ; (Y2 >= 0) && (Y2 < YRES)
759 ; Must set an error code: NO
764 .byte %00000001 ; A pixel sprite
795 ; ------------------------------------------------------------------------
796 ; CIRCLE: Draw a circle around the center X1/Y1 (= ptr1/ptr2) with the
797 ; radius in tmp1 and the current drawing color.
799 ; Must set an error code: NO
801 ; There is no sensible way of drawing a circle on a Lynx. As I would
802 ; have to use line elements to do the circle I rather do it in C than
803 ; create it here in the driver.
805 ; To do a circle please add this to your C program
809 ; 3196, // 11.25 degrees
810 ; 6270, // 22.5 degrees
811 ; 9102, // 33.75 degrees
812 ; 11585, // 45 degrees
813 ; 13623, // 56.25 degrees
814 ; 15137, // 67.5 degrees
815 ; 16069, // 78.75 degrees
816 ; 16384 // 90 degrees
833 ;void tgi_Circle(int x0, int y0, unsigned char r)
836 ; int x1, y1, x2, y2;
838 ; x1 = ((long)sin(0) * r + 8192) / 16384 + x0;
839 ; y1 = ((long)sin(8) * r + 8192) / 16384 + y0;
840 ; for (i = 1; i <= 32; i++) {
841 ; x2 = ((long)sin(i) * r + 8192) / 16384 + x0;
842 ; y2 = ((long)sin(i+8) * r + 8192) / 16384 + y0;
843 ; tgi_line(x1, y1, x2, y2);
849 ;#define tgi_circle tgi_Circle
854 ; ------------------------------------------------------------------------
855 ; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
856 ; direction is passend in X/Y, the text direction is passed in A.
858 ; Must set an error code: NO
867 ; ------------------------------------------------------------------------
868 ; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
869 ; current text style. The text to output is given as a zero terminated
870 ; string with address in ptr3.
872 ; Must set an error code: NO
876 lda TEXTMAGX ; Scale sprite
881 stz text_sprite ; Set normal sprite
885 sta text_sprite ; Set opaque sprite
887 lda DRAWINDEX ; Set color
895 lda X1 ; Set start position
904 ldy #-1 ; Calculate string length
915 rts ; Zero length string
917 iny ; Prepare text_bitmap
921 ldy #8-1 ; 8 pixel lines per character
958 ; and now copy the 8 bytes of that char
964 ; draw char from top to bottom, reading char-data from offset 8-1 to offset 0
967 lda (FONTOFF),y ; *chptr
968 sta text_bitmap,x ;textbuf[y*(1+len+1)+1+x]
1004 ; 96 characters from ASCII 32 to 127
1005 ; 8 pixels wide, 8 pixels high
1006 ; bit value 0 = foreground, bit value 1 = background / transparent
1009 .byte $FF, $FF, $FF, $FF, $FF, $FF, $FF, $FF ;32
1010 .byte $FF, $E7, $FF, $FF, $E7, $E7, $E7, $E7 ;33
1011 .byte $FF, $FF, $FF, $FF, $FF, $99, $99, $99 ;34
1012 .byte $FF, $99, $99, $00, $99, $00, $99, $99 ;35
1013 .byte $FF, $E7, $83, $F9, $C3, $9F, $C1, $E7 ;36
1014 .byte $FF, $B9, $99, $CF, $E7, $F3, $99, $9D ;37
1015 .byte $FF, $C0, $99, $98, $C7, $C3, $99, $C3 ;38
1016 .byte $FF, $FF, $FF, $FF, $FF, $E7, $F3, $F9 ;39
1017 .byte $FF, $F3, $E7, $CF, $CF, $CF, $E7, $F3 ;40
1018 .byte $FF, $CF, $E7, $F3, $F3, $F3, $E7, $CF ;41
1019 .byte $FF, $FF, $99, $C3, $00, $C3, $99, $FF ;42
1020 .byte $FF, $FF, $E7, $E7, $81, $E7, $E7, $FF ;43
1021 .byte $CF, $E7, $E7, $FF, $FF, $FF, $FF, $FF ;44
1022 .byte $FF, $FF, $FF, $FF, $81, $FF, $FF, $FF ;45
1023 .byte $FF, $E7, $E7, $FF, $FF, $FF, $FF, $FF ;46
1024 .byte $FF, $9F, $CF, $E7, $F3, $F9, $FC, $FF ;47
1025 .byte $FF, $C3, $99, $99, $89, $91, $99, $C3 ;48
1026 .byte $FF, $81, $E7, $E7, $E7, $C7, $E7, $E7 ;49
1027 .byte $FF, $81, $9F, $CF, $F3, $F9, $99, $C3 ;50
1028 .byte $FF, $C3, $99, $F9, $E3, $F9, $99, $C3 ;51
1029 .byte $FF, $F9, $F9, $80, $99, $E1, $F1, $F9 ;52
1030 .byte $FF, $C3, $99, $F9, $F9, $83, $9F, $81 ;53
1031 .byte $FF, $C3, $99, $99, $83, $9F, $99, $C3 ;54
1032 .byte $FF, $E7, $E7, $E7, $E7, $F3, $99, $81 ;55
1033 .byte $FF, $C3, $99, $99, $C3, $99, $99, $C3 ;56
1034 .byte $FF, $C3, $99, $F9, $C1, $99, $99, $C3 ;57
1035 .byte $FF, $FF, $E7, $FF, $FF, $E7, $FF, $FF ;58
1036 .byte $CF, $E7, $E7, $FF, $FF, $E7, $FF, $FF ;59
1037 .byte $FF, $F1, $E7, $CF, $9F, $CF, $E7, $F1 ;60
1038 .byte $FF, $FF, $FF, $81, $FF, $81, $FF, $FF ;61
1039 .byte $FF, $8F, $E7, $F3, $F9, $F3, $E7, $8F ;62
1040 .byte $FF, $E7, $FF, $E7, $F3, $F9, $99, $C3 ;63
1043 .byte $FF, $C3, $9D, $9F, $91, $91, $99, $C3 ;0
1044 .byte $FF, $99, $99, $99, $81, $99, $C3, $E7 ;1
1045 .byte $FF, $83, $99, $99, $83, $99, $99, $83 ;2
1046 .byte $FF, $C3, $99, $9F, $9F, $9F, $99, $C3 ;3
1047 .byte $FF, $87, $93, $99, $99, $99, $93, $87 ;4
1048 .byte $FF, $81, $9F, $9F, $87, $9F, $9F, $81 ;5
1049 .byte $FF, $9F, $9F, $9F, $87, $9F, $9F, $81 ;6
1050 .byte $FF, $C3, $99, $99, $91, $9F, $99, $C3 ;7
1051 .byte $FF, $99, $99, $99, $81, $99, $99, $99 ;8
1052 .byte $FF, $C3, $E7, $E7, $E7, $E7, $E7, $C3 ;9
1053 .byte $FF, $C7, $93, $F3, $F3, $F3, $F3, $E1 ;10
1054 .byte $FF, $99, $93, $87, $8F, $87, $93, $99 ;11
1055 .byte $FF, $81, $9F, $9F, $9F, $9F, $9F, $9F ;12
1056 .byte $FF, $9C, $9C, $9C, $94, $80, $88, $9C ;13
1057 .byte $FF, $99, $99, $91, $81, $81, $89, $99 ;14
1058 .byte $FF, $C3, $99, $99, $99, $99, $99, $C3 ;15
1059 .byte $FF, $9F, $9F, $9F, $83, $99, $99, $83 ;16
1060 .byte $FF, $F1, $C3, $99, $99, $99, $99, $C3 ;17
1061 .byte $FF, $99, $93, $87, $83, $99, $99, $83 ;18
1062 .byte $FF, $C3, $99, $F9, $C3, $9F, $99, $C3 ;19
1063 .byte $FF, $E7, $E7, $E7, $E7, $E7, $E7, $81 ;20
1064 .byte $FF, $C3, $99, $99, $99, $99, $99, $99 ;21
1065 .byte $FF, $E7, $C3, $99, $99, $99, $99, $99 ;22
1066 .byte $FF, $9C, $88, $80, $94, $9C, $9C, $9C ;23
1067 .byte $FF, $99, $99, $C3, $E7, $C3, $99, $99 ;24
1068 .byte $FF, $E7, $E7, $E7, $C3, $99, $99, $99 ;25
1069 .byte $FF, $81, $9F, $CF, $E7, $F3, $F9, $81 ;26
1070 .byte $FF, $C3, $CF, $CF, $CF, $CF, $CF, $C3 ;27
1071 .byte $FF, $03, $9D, $CF, $83, $CF, $ED, $F3 ;28
1072 .byte $FF, $C3, $F3, $F3, $F3, $F3, $F3, $C3 ;29
1073 .byte $E7, $E7, $E7, $E7, $81, $C3, $E7, $FF ;30
1074 .byte $FF, $EF, $CF, $80, $80, $CF, $EF, $FF ;31
1078 .byte $FF, $C3, $9D, $9F, $91, $91, $99, $C3 ;224
1079 .byte $FF, $C1, $99, $C1, $F9, $C3, $FF, $FF ;225
1080 .byte $FF, $83, $99, $99, $83, $9F, $9F, $FF ;226
1081 .byte $FF, $C3, $9F, $9F, $9F, $C3, $FF, $FF ;227
1082 .byte $FF, $C1, $99, $99, $C1, $F9, $F9, $FF ;228
1083 .byte $FF, $C3, $9F, $81, $99, $C3, $FF, $FF ;229
1084 .byte $FF, $E7, $E7, $E7, $C1, $E7, $F1, $FF ;230
1085 .byte $83, $F9, $C1, $99, $99, $C1, $FF, $FF ;231
1086 .byte $FF, $99, $99, $99, $83, $9F, $9F, $FF ;232
1087 .byte $FF, $C3, $E7, $E7, $C7, $FF, $E7, $FF ;233
1088 .byte $C3, $F9, $F9, $F9, $F9, $FF, $F9, $FF ;234
1089 .byte $FF, $99, $93, $87, $93, $9F, $9F, $FF ;235
1090 .byte $FF, $C3, $E7, $E7, $E7, $E7, $C7, $FF ;236
1091 .byte $FF, $9C, $94, $80, $80, $99, $FF, $FF ;237
1092 .byte $FF, $99, $99, $99, $99, $83, $FF, $FF ;238
1093 .byte $FF, $C3, $99, $99, $99, $C3, $FF, $FF ;239
1094 .byte $9F, $9F, $83, $99, $99, $83, $FF, $FF ;240
1095 .byte $F9, $F9, $C1, $99, $99, $C1, $FF, $FF ;241
1096 .byte $FF, $9F, $9F, $9F, $99, $83, $FF, $FF ;242
1097 .byte $FF, $83, $F9, $C3, $9F, $C1, $FF, $FF ;243
1098 .byte $FF, $F1, $E7, $E7, $E7, $81, $E7, $FF ;244
1099 .byte $FF, $C1, $99, $99, $99, $99, $FF, $FF ;245
1100 .byte $FF, $E7, $C3, $99, $99, $99, $FF, $FF ;246
1101 .byte $FF, $C9, $C1, $80, $94, $9C, $FF, $FF ;247
1102 .byte $FF, $99, $C3, $E7, $C3, $99, $FF, $FF ;248
1103 .byte $87, $F3, $C1, $99, $99, $99, $FF, $FF ;249
1104 .byte $FF, $81, $CF, $E7, $F3, $81, $FF, $FF ;250
1105 .byte $FF, $C3, $CF, $CF, $CF, $CF, $CF, $C3 ;251
1106 .byte $FF, $03, $9D, $CF, $83, $CF, $ED, $F3 ;252
1107 .byte $FF, $C3, $F3, $F3, $F3, $F3, $F3, $C3 ;253
1108 .byte $E7, $E7, $E7, $E7, $81, $C3, $E7, $FF ;254
1109 .byte $FF, $EF, $CF, $80, $80, $CF, $EF, $FF ;255