TinySB Sub-Layer Functions

; PROJECT : TinySBRunTime
; EDITED  : 9/5/2016
; ---------------------------------------------------------------------

//NYI not yet implemented
Psub parse(mystring$)
endpsub

psub get_color#(color$)
endpsub

//This does a few things, it draws the text page on the screen and the bg layers including ones shown/hidden
psub frame_render()
rendertoscreen
DRAWBGS()
render_TEXTPAGE()
endpsub

//Draw the textpage onto the screen
psub render_TEXTPAGE()
drawimage text_page, 0, 0, 1
endpsub

//This should be in charge of stepping the program stack foreward
psub step_()
inc pc //Increment the program counter
endpsub

//Used for utility to resize the stack of the program
psub resize_stack(value)
redim program_stack$(value)
endpsub

psub resize_labels(value)
redim labels$(value) //the labels themselves matter
redim label_pointers(value) //take care of the pointers to these are important
endpsub

psub getlabelbyvalue(value)
endpsub labels$(value)

psub add_returnstack(pc_pointer)
	//first increase the return stack size by 1
inc return_stack_size
	//We also have to resize the return stack array now
		resize_Rstack(return_stack_size)
return_stack(return_stack_size)=pc //the address or line number to return to after the jump
pc = pc_pointer //the address or line number we are jumping to by directly modifying the pc pointer.
	//the logic is simple instead of parsing where we are if we see return we pop a value off the stack
		//and go back to the last pc address
endpsub

//This should literally take care of gosub
psub gosub_(label_name$)
index = findlabelbystring(label_name$)
if index>0
	add_returnstack(index)
	endif
endpsub

psub goto_(label_name$)
index = findlabelbystring(label_name$)
address = label_pointers(index)
if index>0
	jump_pc(address) //changed value to address this would have been broken
endif
endpsub

psub remove_returnstack()
	//first decrement the return stack size by 1
	dec return_stack_size
		//we have to also resize it
			resize_Rstack(return_stack_size)
		//next store the pc address from the jump below us
			pc = return_stack(return_stack_size)
			//the logic is simple, we're going back to the last place we had saved (line number)
				//to continue execution.
						//As you'd expect in this way we can have 5 or even 10 different lines to eventually return to
endpsub

psub findlabelbystring(str_$)
for t=0 to getarrayelements( labels$() )
	if str_$ = labels$(t)
		index=t
		exitfor
	endif
next t
endpsub index

psub resize_Rstack(value)
redim return_stack(value)
endpsub

//this takes care of jumping to the line number or index of the program to run
	//Probably used by goto and other commands like it
psub jump_pc(value)
pc = value
endpsub

//utility for testing
	//puts an item in the program stack,
		//increments stack counter
psub put(command$)
program_stack$(program_stack_size) = command$
inc program_stack_size //increments the program stack size
resize_stack(program_stack_size)
endpsub

Psub find_labels()
	dim label_strings$(1) //it should auto resize
		current_label = 1 //set the temporary current label counter so we actually have a label counter
	//pre parsing labels so we know what their line numbers are
	for t=1 to program_stack_size //Go through the whoollle stack
		entry_string$ = program_stack$(t)

			//Lots of nested ifs here. basically just check the label string
		if left$(entry_string$, 1)="@"
				//Ok we found one, let's see if we can get the full string of the label we need to store it
				Tokens=SplitToArray(entry_string$," ",label_strings$(),1)
				if len(label_strings$(1))>0 and left$(label_strings$(1), 1)="@"
						//Just double check that the @ symbol is there.

								//and this adds the label to our list
							add_label(label_strings$(1), t, current_label)
							inc current_label //don't forget to increment this or we'll over write
								//a previously saved or stored label
										//and now gosub/goto should work if called


					endif

			endif
		next t

endpsub


//This function handles dynamically adding new labels to the label list pre-parsing
	//This is never used during runtime and it better not ever be ;)
psub add_label(label$, pc_index, current_label)
		//A little safety to make sure it doesn't break things and
			//that this array stays within it's indexes
if current_label > label_list_size
resize_labels(current_label)
endif
	//end of safety
labels$(current_label) = label$ //the actual label's name
label_pointers(current_label) = pc_index //the pc address it's on
endpsub

Psub parse_command(index)
dim command_strings$(20)
dim command_strings_$(20)

Tokens=SplitToArray(program_stack$(index),", ",command_strings$(),1)

		//Parse the color command
	for g=1 to Tokens
		if command_strings$(g) ="COLOR"
			//Tokens=SplitToArray(command_strings$(g+1),",",command_strings_$(),1)

			color_1$ = command_strings$(g+1)
			color_2$ = command_strings$(g+2)
			color_#(color_1$, color_2$)
			exitfor
	endif
		//Kind of parse the print command
	if command_strings$(g) = "Print"
		output_string$ = command_strings$(g+1)
		//locate(10, g)
		print_string(output_string$)
		endif

			if command_strings$(g) = "goto"
					//We'll get the goto label first
					goto_label$ = command_strings$(g+1)
						//Next we're going to see if it has an @
							if left$(goto_label$, 1)="@"
								//we're dealing with a correct label
										goto_(goto_label$) //and this should change the pc address!
										exitfor	//now exit the for loop
							endif
					endif

					if command_strings$(g) = "locate"
							//we'll try to get the X and Y out of this
								X$ = command_strings$(g+1)
								Y$ = command_strings$(g+2)

									//if right$(X$, 1)="," then X$=left$(X$, len(X$)-1)
									x = val(X$)
									y = val(Y$)
									//locate(5, 15)
									//print_string(X$)
									//locate(5, 16)
									//print_string(Y$)
									locate(x, y)// actually try to use the command
									//locate(20, 7)
									exitfor
							endif




	next g


endpsub