Implementing TGI

git-svn-id: svn://svn.cc65.org/cc65/trunk@1311 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/tgi/tgi-kernel.s

@@ -0,0 +1,85 @@
+;
+; Ullrich von Bassewitz, 21.06.2002
+;
+; Common functions of the tgi graphics kernel.
+;
+
+        .include        "tgi-kernel.inc"
+
+;----------------------------------------------------------------------------
+; Variables
+
+.bss
+
+_tgi_drv:	.res	2		; Pointer to driver
+_tgi_error:	.res	1		; Last error code
+
+
+.data
+
+; Jump table for the driver functions.
+
+tgi_install:	jmp	$0000
+tgi_deinstall:	jmp	$0000
+tgi_init:       jmp	$0000
+tgi_post:       jmp	$0000
+tgi_control:    jmp	$0000
+tgi_clear:      jmp     $0000
+tgi_setcolor:   jmp     $0000
+tgi_setpixel:   jmp     $0000
+tgi_getpixel:   jmp     $0000
+tgi_line:       jmp     $0000
+tgi_bar:        jmp     $0000
+tgi_circle:     jmp     $0000
+
+
+;----------------------------------------------------------------------------
+; Setup the TGI driver once it is loaded.
+
+tgi_setup:
+	lda	_tgi_drv
+	sta	ptr1
+	lda	_tgi_drv+1
+	sta	ptr1+1
+
+        ldy     #TGI_HDR_JUMPTAB
+        ldx     #1
+
+@L1:    lda     (ptr1),y
+        sta     tgi_install,x
+        iny
+        inx
+        lda     (ptr1),y
+        sta     tgi_install,x
+        inx
+        cpx     #(TGI_HDR_JMPCOUNT*3)
+        bne     @L1
+
+        lda     #$00
+        sta     _tgi_error
+
+        jsr     tgi_install             ; Call driver install routine
+
+;       jmp     tgi_fetch_error
+
+;----------------------------------------------------------------------------
+; Fetch the error code from the driver and place it into the global error
+; variable.
+
+tgi_fetch_error:
+        jsr     tgi_set_ptr
+  	ldy	#TGI_HDR_ERROR
+  	lda	(ptr1),y
+  	sta	_tgi_error
+  	rts
+
+;----------------------------------------------------------------------------
+; Load the pointer to the tgi driver into ptr1.
+
+tgi_set_ptr:
+  	lda	_tgi_drv
+  	sta	ptr1
+  	lda	_tgi_drv+1
+  	sta	ptr1+1
+        rts
+