Make use of the IRQ to swap view and draw pages when they aren't visible.

git-svn-id: svn://svn.cc65.org/cc65/trunk@4145 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/lynx/lynx-160-102-16.s b/libsrc/lynx/lynx-160-102-16.s
index 8a76af863b4e878dfad88e1b921d1b1fcc4af017..7825e2d8e53b57b0a1896b81344ab7d6f22c0146 100644 (file)
--- a/libsrc/lynx/lynx-160-102-16.s
+++ b/libsrc/lynx/lynx-160-102-16.s
@@ -67,7 +67,7 @@
         .addr   CIRCLE
         .addr   TEXTSTYLE
         .addr   OUTTEXT
-        .addr   0                       ; IRQ entry is unused
+        .addr   IRQ
 
 
 ; ------------------------------------------------------------------------
@@ -104,6 +104,11 @@ TEXTMAGY:       .res    1
 TEXTDIR:        .res    1
 BGINDEX:        .res    1      ; Pen to use for text background
 
+; Double buffer IRQ stuff
+DRAWPAGE:      .res    1
+SWAPREQUEST:   .res    1
+VBLHOOK:       .res    3
+
 text_bitmap:    .res   8*(1+20+1)+1
 ; 8 rows with (one offset-byte plus 20 character bytes plus one fill-byte) plus one 0-offset-byte
 
@@ -161,6 +166,10 @@ INSTALL:
        sta     TEXTMAGX
        sta     TEXTMAGY
        stz     BGINDEX
+       stz     DRAWPAGE
+       stz     SWAPREQUEST
+       lda     #$60            ; rts op-code
+       sta     VBLHOOK
         rts
 
 
@@ -228,23 +237,86 @@ GETERROR:
 ; To do a flip-screen call tgi_ioctl(1, 0)
 ;
 ; To set the background index for text outputs call tgi_ioctl(2, bgindex)
+;
+; To set the frame rate for the display hardware call tgi_ioctl(3, rate)
+;
+; To make a request for swapping the display buffers call tgi_ioctl(4, dataptr)
+; If the value of the char pointed to by the dataptr is 0 then fill in the
+; value of the char with the current state of the swap buffer 0 = idle, 1 = busy
+; If the value is not 0 then activate the swap function at next VBL interrupt
+;
+; Set an address for a subroutine you want to call at every VBL
+; tgi_ioctl(5, hook)
 
 CONTROL:
-       cmp     #2
-       bne     @L0
-       lda     ptr1
-       sta     BGINDEX
+        pha                    ; Almost all control routines succeed
         lda     #TGI_ERR_OK
        sta     ERROR
+       pla
+       cmp     #5
+       bne ControlSwapRequest
+
+       lda     ptr1            ; Set IRQ routine to be called at VBL
+       sta     VBLHOOK+1
+       lda     ptr1+1
+       sta     VBLHOOK+2
+       lda     #$43            ; jmp op-code
+       sta     VBLHOOK
+       rts
+
+ControlSwapRequest:
+       cmp     #4
+       bne     ControlFramerate
+
+       lda     ptr1            ; Swap request
+       bne     @L0
+       lda     SWAPREQUEST
+       rts
+@L0:    sta    SWAPREQUEST
+       rts
+
+ControlFramerate:
+       cmp     #3
+       bne     ControlTextBG
+
+               cmp     #75             ; Set framerate
+               beq     rate75
+               cmp     #60
+               beq     rate60
+        cmp     #50
+               beq     rate50
+        lda     #TGI_ERR_INV_ARG
+       sta     ERROR
         rts
-@L0:
+rate50: lda     #$bd           ; 50 Hz
+               ldx     #$31
+               bra     setRate
+rate60: lda     #$9e           ; 60 Hz
+               ldx     #$29
+               bra     setRate
+rate75: lda     #$7e           ; 75 Hz
+               ldx     #$20
+setRate:
+        sta     HTIMBKUP
+               stx     PBKUP
+       rts
+
+ControlTextBG:
+       cmp     #2
+       bne     ControlFlipScreen
+
+       lda     ptr1            ; Set text background color
+       sta     BGINDEX
+       rts
+
+ControlFlipScreen:
        cmp     #1
-       bne     @L2
-       lda     __sprsys
+       bne     ControlDrawSprite
+
+       lda     __sprsys        ; Flip screen
        eor     #8
        sta     __sprsys
        sta     SPRSYS
-
        lda     __viddma
        eor     #2
        sta     __viddma
@@ -252,7 +324,7 @@ CONTROL:
        ldy     VIEWPAGEL
        ldx     VIEWPAGEH
        and     #2
-       beq     @L1
+       beq     NotFlipped
        clc
        tya
        adc     #<8159
@@ -260,13 +332,12 @@ CONTROL:
        txa
        adc     #>8159
        tax
-@L1:
+NotFlipped:
        sty     DISPADRL
        stx     DISPADRH
-        lda     #TGI_ERR_OK
-       sta     ERROR
         rts
-@L2:
+
+ControlDrawSprite:
        lda     ptr1            ; Get the sprite address
        ldx     ptr1+1
 
@@ -280,10 +351,10 @@ draw_sprite:                      ; Draw it in render buffer
                lda     #1
                sta     SPRGO
                stz     SDONEACK
-@L3:    stz     CPUSLEEP
+@L0:    stz     CPUSLEEP
                lda     SPRSYS
                lsr
-               bcs     @L3
+               bcs     @L0
                stz     SDONEACK
         lda     #TGI_ERR_OK
        sta     ERROR
@@ -374,6 +445,44 @@ SETDRAWPAGE:
                stx     DRAWPAGEH
         rts
 
+; ------------------------------------------------------------------------
+; IRQ: VBL interrupt handler
+;
+
+TIMER0_INTERRUPT = $01
+TIMER1_INTERRUPT = $02
+TIMER2_INTERRUPT = $04
+TIMER3_INTERRUPT = $08
+TIMER4_INTERRUPT = $10
+TIMER5_INTERRUPT = $20
+TIMER6_INTERRUPT = $40
+TIMER7_INTERRUPT = $80
+
+HBL_INTERRUPT = TIMER0_INTERRUPT
+VBL_INTERRUPT = TIMER2_INTERRUPT
+SERIAL_INTERRUPT = TIMER4_INTERRUPT
+
+IRQ:
+       lda     INTSET          ; Poll all pending interrupts
+       and     #VBL_INTERRUPT
+        bne    IRQVBL
+       clc                     ; Not a VBL interrupt - exit
+       rts
+IRQVBL: sta    INTRST          ; Clear interrupt
+       lda     SWAPREQUEST
+       bne     @L0
+       lda     DRAWPAGE
+       jsr     SETVIEWPAGE
+       lda     DRAWPAGE
+       eor     #1
+       sta     DRAWPAGE
+       jsr     SETDRAWPAGE
+       stz     SWAPREQUEST
+@L0:
+       jsr     VBLHOOK
+       sec
+       rts
+
 ; ------------------------------------------------------------------------
 ; SETCOLOR: Set the drawing color (in A). The new color is already checked
 ; to be in a valid range (0..maxcolor-1).