graphics.inc

This a basic compiler for MSP430

; Graphical support routines

        .bss

color	ds.b	1

	.code

// PLOT x, y
x_plot:
	call	#eval_expr
	call	#check_comma
	push.w	r14
	call	#eval_expr
	pop.w	r15
	call	#plot
	jmp	term

; COLOR expr
x_color:
	call	#eval_expr                   ; evaluate color
	mov.b	r14, &color                  ; only save eight bits of it, though
	jmp	term                         ; terminate statement

; LINE x0, y0 TO x1, y1
x_line:
	call	#eval_expr
	push.w	r14
	call	#check_comma
	call	#eval_expr
	push.w	r14
	cmp.b	#T_TO, r4
	jnz	syntax_error
	mov.b   @tp+, r4
	call	#eval_expr
	push.w	r14
	call	#check_comma
	call	#eval_expr
	pop.w	r15
	pop.w   r12
	pop.w   r13