Canvas Drawing Opcodes

CLEAR

Clears the entire canvas.

CLEAR

Opcode: CLR

Operands: None

MOVE

Moves the drawing cursor to a position without drawing.

MOVE R0, R1    ; Move to (x, y) where R0=x, R1=y

Opcode: MOV

Operands: reg_x, reg_y

Note: Coordinates are typically in graph space (scaled by 100), which is converted to screen pixels automatically.

DRAW

Draws a line from the current position to a new position.

DRAW R0, R1    ; Draw line to (x, y) where R0=x, R1=y

Opcode: DRW

Operands: reg_x, reg_y

Note: The line is added to the current path but not rendered until STROKE is called.

STROKE

Renders (strokes) the current path, making all drawn lines visible.

STROKE

Opcode: STR

Operands: None

Note: You must call STROKE after drawing lines to make them visible.

Drawing a Line

; Draw a line from (-5, -5) to (5, 5)
CLEAR
; Start point: (-5, -5) scaled by 100
LOAD R0, -500    ; x1
LOAD R1, -500    ; y1
MOVE R0, R1      ; Move to start point
; End point: (5, 5) scaled by 100
LOAD R0, 500     ; x2
LOAD R1, 500     ; y2
DRAW R0, R1      ; Draw line
STROKE           ; Render it

Drawing a Square

; Draw a square from (-3, -3) to (3, 3)
CLEAR
; Bottom-left
LOAD R0, -300
LOAD R1, -300
MOVE R0, R1
; Top-left
LOAD R0, -300
LOAD R1, 300
DRAW R0, R1
; Top-right
LOAD R0, 300
LOAD R1, 300
DRAW R0, R1
; Bottom-right
LOAD R0, 300
LOAD R1, -300
DRAW R0, R1
; Close square
LOAD R0, -300
LOAD R1, -300
DRAW R0, R1
STROKE

Graph Coordinates

In the calculator console, coordinates are in graph space (scaled by 100):

• 500 = 5.0 in graph units
• -300 = -3.0 in graph units

These are automatically converted to screen pixels based on the graph window settings.

Screen Coordinates

If drawing directly (not through calculator), coordinates are in screen pixels:

• 0, 0 = top-left corner
• width, height = bottom-right corner