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
111 text_bitmap: .res 8*(1+20+1)+1
112 ; 8 rows with (one offset-byte plus 20 character bytes plus one fill-byte) plus one 0-offset-byte
114 ; Constants and tables
118 DEFPALETTE: .byte >$000
151 PALETTESIZE = * - DEFPALETTE
155 ; ------------------------------------------------------------------------
156 ; INSTALL routine. Is called after the driver is loaded into memory. May
157 ; initialize anything that has to be done just once. Is probably empty
160 ; Must set an error code: NO
173 ; ------------------------------------------------------------------------
174 ; UNINSTALL routine. Is called before the driver is removed from memory. May
175 ; clean up anything done by INSTALL but is probably empty most of the time.
177 ; Must set an error code: NO
184 ; ------------------------------------------------------------------------
185 ; INIT: Changes an already installed device from text mode to graphics
187 ; Note that INIT/DONE may be called multiple times while the driver
188 ; is loaded, while INSTALL is only called once, so any code that is needed
189 ; to initializes variables and so on must go here. Setting palette and
190 ; clearing the screen is not needed because this is called by the graphics
192 ; The graphics kernel will never call INIT when a graphics mode is already
193 ; active, so there is no need to protect against that.
195 ; Must set an error code: YES
199 ; Enable interrupts for VBL
202 ; Set up collision buffer to $A058
207 ; Put collision index before sprite data
212 ; Done, reset the error code
217 ; ------------------------------------------------------------------------
218 ; DONE: Will be called to switch the graphics device back into text mode.
219 ; The graphics kernel will never call DONE when no graphics mode is active,
220 ; so there is no need to protect against that.
222 ; Must set an error code: NO
228 ; ------------------------------------------------------------------------
229 ; GETERROR: Return the error code in A and clear it.
237 ; ------------------------------------------------------------------------
238 ; CONTROL: Platform/driver specific entry point.
240 ; Must set an error code: YES
242 ; The TGI lacks a way to draw sprites. As that functionality is vital to
243 ; Lynx games we borrow this CONTROL function to implement the still
244 ; missing tgi_draw_sprite funtion. To use this in your C-program
245 ; do a #define tgi_draw_sprite(spr) tgi_ioctl(0, spr)
247 ; To do a flip-screen call tgi_ioctl(1, 0)
249 ; To set the background index for text outputs call tgi_ioctl(2, bgindex)
251 ; To set the frame rate for the display hardware call tgi_ioctl(3, rate)
253 ; To check if the drawing engine is busy with the previous swap you can
254 ; call tgi_ioctl(4, 0). It returns 0 if idle and 1 if busy
256 ; To update displays you can call tgi_ioctl(4, 1) it will wait for the
257 ; next VBL interrupt and swap draw and view buffers.
259 ; Activate or deactivate collision detection by calling tgi_ioctl(5, 0/1).
262 pha ; Almost all control routines succeed
284 lda ptr1 ; Swap request
296 cmp #75 ; Set framerate
305 rate50: lda #$bd ; 50 Hz
308 rate60: lda #$9e ; 60 Hz
311 rate75: lda #$7e ; 75 Hz
320 bne ControlFlipScreen
322 lda ptr1 ; Set text background color
328 bne ControlDrawSprite
330 lda __sprsys ; Flip screen
355 lda ptr1 ; Get the sprite address
358 draw_sprite: ; Draw it in render buffer
377 ; ------------------------------------------------------------------------
378 ; CLEAR: Clears the screen.
380 ; Must set an error code: NO
385 .byte 3,%10000100,%00000000, $0 ; A pixel bitmap
387 .byte %00000001 ; A pixel sprite
398 CLEAR: lda #<cls_sprite
402 ; ------------------------------------------------------------------------
403 ; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
404 ; The page number is already checked to be valid by the graphics kernel.
406 ; Must set an error code: NO (will only be called if page ok)
408 ; It is a good idea to call this function during the vertical blanking
409 ; period. If you call it in the middle of the screen update then half of
410 ; the drawn frame will be from the old buffer and the other half is
411 ; from the new buffer. This is usually noticed by the user.
415 beq @L1 ; page == maxpages-1
423 sty VIEWPAGEL ; Save viewpage for getpixel
426 lda __viddma ; Process flipped displays
441 ; ------------------------------------------------------------------------
442 ; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
443 ; The page number is already checked to be valid by the graphics kernel.
445 ; Must set an error code: NO (will only be called if page ok)
450 beq @L1 ; page == maxpages-1
462 ; ------------------------------------------------------------------------
463 ; IRQ: VBL interrupt handler
467 lda INTSET ; Poll all pending interrupts
469 beq IRQEND ; Exit if not a VBL interrupt
485 ; ------------------------------------------------------------------------
486 ; SETCOLOR: Set the drawing color (in A). The new color is already checked
487 ; to be in a valid range (0..maxcolor-1).
489 ; Must set an error code: NO (will only be called if color ok)
496 ; ------------------------------------------------------------------------
497 ; SETPALETTE: Set the palette (not available with all drivers/hardware).
498 ; A pointer to the palette is passed in ptr1. Must set an error if palettes
501 ; Must set an error code: YES
507 sta GCOLMAP,y ; $FDA0
511 ; Done, reset the error code
517 ; ------------------------------------------------------------------------
518 ; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
519 ; set the palette should return the default palette here, so there's no
520 ; way for this function to fail.
522 ; Must set an error code: NO
526 lda #<GCOLMAP ; $FDA0
530 ; ------------------------------------------------------------------------
531 ; GETDEFPALETTE: Return the default palette for the driver in A/X. All
532 ; drivers should return something reasonable here, even drivers that don't
533 ; support palettes, otherwise the caller has no way to determine the colors
534 ; of the (not changeable) palette.
536 ; Must set an error code: NO (all drivers must have a default palette)
544 ; ------------------------------------------------------------------------
545 ; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
546 ; color. The coordinates passed to this function are never outside the
547 ; visible screen area, so there is no need for clipping inside this function.
549 ; Must set an error code: NO
554 .byte %00000001 ; A pixel sprite
576 ; ------------------------------------------------------------------------
577 ; GETPIXEL: Read the color value of a pixel and return it in A/X. The
578 ; coordinates passed to this function are never outside the visible screen
579 ; area, so there is no need for clipping inside this function.
584 sta MATHD ; Hardware multiply
621 ; ------------------------------------------------------------------------
622 ; LINE: Draw a line from X1/Y1 to X2/Y2, where X1/Y1 = ptr1/ptr2 and
623 ; X2/Y2 = ptr3/ptr4 using the current drawing color.
625 ; Must set an error code: NO
630 .byte 0 ; Will be replaced by the code
678 lda #%00000000 ; Not flipped
696 lda #%00010000 ; Vertical flip
711 sta MATHP ; hardware divide
724 bmi @L3 ; wait for math done (bit 7 of sprsys)
744 ; ------------------------------------------------------------------------
745 ; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
746 ; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
747 ; Contrary to most other functions, the graphics kernel will sort and clip
748 ; the coordinates before calling the driver, so on entry the following
749 ; conditions are valid:
752 ; (X1 >= 0) && (X1 < XRES)
753 ; (X2 >= 0) && (X2 < XRES)
754 ; (Y1 >= 0) && (Y1 < YRES)
755 ; (Y2 >= 0) && (Y2 < YRES)
757 ; Must set an error code: NO
762 .byte %00000001 ; A pixel sprite
793 ; ------------------------------------------------------------------------
794 ; CIRCLE: Draw a circle around the center X1/Y1 (= ptr1/ptr2) with the
795 ; radius in tmp1 and the current drawing color.
797 ; Must set an error code: NO
799 ; There is no sensible way of drawing a circle on a Lynx. As I would
800 ; have to use line elements to do the circle I rather do it in C than
801 ; create it here in the driver.
803 ; To do a circle please add this to your C program
807 ; 3196, // 11.25 degrees
808 ; 6270, // 22.5 degrees
809 ; 9102, // 33.75 degrees
810 ; 11585, // 45 degrees
811 ; 13623, // 56.25 degrees
812 ; 15137, // 67.5 degrees
813 ; 16069, // 78.75 degrees
814 ; 16384 // 90 degrees
831 ;void tgi_Circle(int x0, int y0, unsigned char r)
834 ; int x1, y1, x2, y2;
836 ; x1 = ((long)sin(0) * r + 8192) / 16384 + x0;
837 ; y1 = ((long)sin(8) * r + 8192) / 16384 + y0;
838 ; for (i = 1; i <= 32; i++) {
839 ; x2 = ((long)sin(i) * r + 8192) / 16384 + x0;
840 ; y2 = ((long)sin(i+8) * r + 8192) / 16384 + y0;
841 ; tgi_line(x1, y1, x2, y2);
847 ;#define tgi_circle tgi_Circle
852 ; ------------------------------------------------------------------------
853 ; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
854 ; direction is passend in X/Y, the text direction is passed in A.
856 ; Must set an error code: NO
865 ; ------------------------------------------------------------------------
866 ; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
867 ; current text style. The text to output is given as a zero terminated
868 ; string with address in ptr3.
870 ; Must set an error code: NO
874 lda TEXTMAGX ; Scale sprite
879 stz text_sprite ; Set normal sprite
883 sta text_sprite ; Set opaque sprite
885 lda DRAWINDEX ; Set color
893 lda X1 ; Set start position
902 ldy #-1 ; Calculate string length
913 rts ; Zero length string
915 iny ; Prepare text_bitmap
919 ldy #8-1 ; 8 pixel lines per character
956 ; and now copy the 8 bytes of that char
962 ; draw char from top to bottom, reading char-data from offset 8-1 to offset 0
965 lda (FONTOFF),y ; *chptr
966 sta text_bitmap,x ;textbuf[y*(1+len+1)+1+x]
1002 ; 96 characters from ASCII 32 to 127
1003 ; 8 pixels wide, 8 pixels high
1004 ; bit value 0 = foreground, bit value 1 = background / transparent
1007 .byte $FF, $FF, $FF, $FF, $FF, $FF, $FF, $FF ;32
1008 .byte $FF, $E7, $FF, $FF, $E7, $E7, $E7, $E7 ;33
1009 .byte $FF, $FF, $FF, $FF, $FF, $99, $99, $99 ;34
1010 .byte $FF, $99, $99, $00, $99, $00, $99, $99 ;35
1011 .byte $FF, $E7, $83, $F9, $C3, $9F, $C1, $E7 ;36
1012 .byte $FF, $B9, $99, $CF, $E7, $F3, $99, $9D ;37
1013 .byte $FF, $C0, $99, $98, $C7, $C3, $99, $C3 ;38
1014 .byte $FF, $FF, $FF, $FF, $FF, $E7, $F3, $F9 ;39
1015 .byte $FF, $F3, $E7, $CF, $CF, $CF, $E7, $F3 ;40
1016 .byte $FF, $CF, $E7, $F3, $F3, $F3, $E7, $CF ;41
1017 .byte $FF, $FF, $99, $C3, $00, $C3, $99, $FF ;42
1018 .byte $FF, $FF, $E7, $E7, $81, $E7, $E7, $FF ;43
1019 .byte $CF, $E7, $E7, $FF, $FF, $FF, $FF, $FF ;44
1020 .byte $FF, $FF, $FF, $FF, $81, $FF, $FF, $FF ;45
1021 .byte $FF, $E7, $E7, $FF, $FF, $FF, $FF, $FF ;46
1022 .byte $FF, $9F, $CF, $E7, $F3, $F9, $FC, $FF ;47
1023 .byte $FF, $C3, $99, $99, $89, $91, $99, $C3 ;48
1024 .byte $FF, $81, $E7, $E7, $E7, $C7, $E7, $E7 ;49
1025 .byte $FF, $81, $9F, $CF, $F3, $F9, $99, $C3 ;50
1026 .byte $FF, $C3, $99, $F9, $E3, $F9, $99, $C3 ;51
1027 .byte $FF, $F9, $F9, $80, $99, $E1, $F1, $F9 ;52
1028 .byte $FF, $C3, $99, $F9, $F9, $83, $9F, $81 ;53
1029 .byte $FF, $C3, $99, $99, $83, $9F, $99, $C3 ;54
1030 .byte $FF, $E7, $E7, $E7, $E7, $F3, $99, $81 ;55
1031 .byte $FF, $C3, $99, $99, $C3, $99, $99, $C3 ;56
1032 .byte $FF, $C3, $99, $F9, $C1, $99, $99, $C3 ;57
1033 .byte $FF, $FF, $E7, $FF, $FF, $E7, $FF, $FF ;58
1034 .byte $CF, $E7, $E7, $FF, $FF, $E7, $FF, $FF ;59
1035 .byte $FF, $F1, $E7, $CF, $9F, $CF, $E7, $F1 ;60
1036 .byte $FF, $FF, $FF, $81, $FF, $81, $FF, $FF ;61
1037 .byte $FF, $8F, $E7, $F3, $F9, $F3, $E7, $8F ;62
1038 .byte $FF, $E7, $FF, $E7, $F3, $F9, $99, $C3 ;63
1041 .byte $FF, $C3, $9D, $9F, $91, $91, $99, $C3 ;0
1042 .byte $FF, $99, $99, $99, $81, $99, $C3, $E7 ;1
1043 .byte $FF, $83, $99, $99, $83, $99, $99, $83 ;2
1044 .byte $FF, $C3, $99, $9F, $9F, $9F, $99, $C3 ;3
1045 .byte $FF, $87, $93, $99, $99, $99, $93, $87 ;4
1046 .byte $FF, $81, $9F, $9F, $87, $9F, $9F, $81 ;5
1047 .byte $FF, $9F, $9F, $9F, $87, $9F, $9F, $81 ;6
1048 .byte $FF, $C3, $99, $99, $91, $9F, $99, $C3 ;7
1049 .byte $FF, $99, $99, $99, $81, $99, $99, $99 ;8
1050 .byte $FF, $C3, $E7, $E7, $E7, $E7, $E7, $C3 ;9
1051 .byte $FF, $C7, $93, $F3, $F3, $F3, $F3, $E1 ;10
1052 .byte $FF, $99, $93, $87, $8F, $87, $93, $99 ;11
1053 .byte $FF, $81, $9F, $9F, $9F, $9F, $9F, $9F ;12
1054 .byte $FF, $9C, $9C, $9C, $94, $80, $88, $9C ;13
1055 .byte $FF, $99, $99, $91, $81, $81, $89, $99 ;14
1056 .byte $FF, $C3, $99, $99, $99, $99, $99, $C3 ;15
1057 .byte $FF, $9F, $9F, $9F, $83, $99, $99, $83 ;16
1058 .byte $FF, $F1, $C3, $99, $99, $99, $99, $C3 ;17
1059 .byte $FF, $99, $93, $87, $83, $99, $99, $83 ;18
1060 .byte $FF, $C3, $99, $F9, $C3, $9F, $99, $C3 ;19
1061 .byte $FF, $E7, $E7, $E7, $E7, $E7, $E7, $81 ;20
1062 .byte $FF, $C3, $99, $99, $99, $99, $99, $99 ;21
1063 .byte $FF, $E7, $C3, $99, $99, $99, $99, $99 ;22
1064 .byte $FF, $9C, $88, $80, $94, $9C, $9C, $9C ;23
1065 .byte $FF, $99, $99, $C3, $E7, $C3, $99, $99 ;24
1066 .byte $FF, $E7, $E7, $E7, $C3, $99, $99, $99 ;25
1067 .byte $FF, $81, $9F, $CF, $E7, $F3, $F9, $81 ;26
1068 .byte $FF, $C3, $CF, $CF, $CF, $CF, $CF, $C3 ;27
1069 .byte $FF, $03, $9D, $CF, $83, $CF, $ED, $F3 ;28
1070 .byte $FF, $C3, $F3, $F3, $F3, $F3, $F3, $C3 ;29
1071 .byte $E7, $E7, $E7, $E7, $81, $C3, $E7, $FF ;30
1072 .byte $FF, $EF, $CF, $80, $80, $CF, $EF, $FF ;31
1076 .byte $FF, $C3, $9D, $9F, $91, $91, $99, $C3 ;224
1077 .byte $FF, $C1, $99, $C1, $F9, $C3, $FF, $FF ;225
1078 .byte $FF, $83, $99, $99, $83, $9F, $9F, $FF ;226
1079 .byte $FF, $C3, $9F, $9F, $9F, $C3, $FF, $FF ;227
1080 .byte $FF, $C1, $99, $99, $C1, $F9, $F9, $FF ;228
1081 .byte $FF, $C3, $9F, $81, $99, $C3, $FF, $FF ;229
1082 .byte $FF, $E7, $E7, $E7, $C1, $E7, $F1, $FF ;230
1083 .byte $83, $F9, $C1, $99, $99, $C1, $FF, $FF ;231
1084 .byte $FF, $99, $99, $99, $83, $9F, $9F, $FF ;232
1085 .byte $FF, $C3, $E7, $E7, $C7, $FF, $E7, $FF ;233
1086 .byte $C3, $F9, $F9, $F9, $F9, $FF, $F9, $FF ;234
1087 .byte $FF, $99, $93, $87, $93, $9F, $9F, $FF ;235
1088 .byte $FF, $C3, $E7, $E7, $E7, $E7, $C7, $FF ;236
1089 .byte $FF, $9C, $94, $80, $80, $99, $FF, $FF ;237
1090 .byte $FF, $99, $99, $99, $99, $83, $FF, $FF ;238
1091 .byte $FF, $C3, $99, $99, $99, $C3, $FF, $FF ;239
1092 .byte $9F, $9F, $83, $99, $99, $83, $FF, $FF ;240
1093 .byte $F9, $F9, $C1, $99, $99, $C1, $FF, $FF ;241
1094 .byte $FF, $9F, $9F, $9F, $99, $83, $FF, $FF ;242
1095 .byte $FF, $83, $F9, $C3, $9F, $C1, $FF, $FF ;243
1096 .byte $FF, $F1, $E7, $E7, $E7, $81, $E7, $FF ;244
1097 .byte $FF, $C1, $99, $99, $99, $99, $FF, $FF ;245
1098 .byte $FF, $E7, $C3, $99, $99, $99, $FF, $FF ;246
1099 .byte $FF, $C9, $C1, $80, $94, $9C, $FF, $FF ;247
1100 .byte $FF, $99, $C3, $E7, $C3, $99, $FF, $FF ;248
1101 .byte $87, $F3, $C1, $99, $99, $99, $FF, $FF ;249
1102 .byte $FF, $81, $CF, $E7, $F3, $81, $FF, $FF ;250
1103 .byte $FF, $C3, $CF, $CF, $CF, $CF, $CF, $C3 ;251
1104 .byte $FF, $03, $9D, $CF, $83, $CF, $ED, $F3 ;252
1105 .byte $FF, $C3, $F3, $F3, $F3, $F3, $F3, $C3 ;253
1106 .byte $E7, $E7, $E7, $E7, $81, $C3, $E7, $FF ;254
1107 .byte $FF, $EF, $CF, $80, $80, $CF, $EF, $FF ;255