Low-level graphical functions:
From Wiki pLua
• pmode(): returns 4 numbers: screen width, screen height, screen depth and 1 or 0 indicating if the screen supports color.
• pclear([c]): erases the screen with the background color or with the optional c color, and moves the cursor to 0,0. Returns nothing.
• pcolor(fg [,bg]): sets the foreground color (fg) and optionally the background color (bg). Returns nothing.
• prgb(r, g, b): returns the color equivalent to the (Red,Green,Blue) components.
• ppos(): returns 2 numbers with the current x,y cursor position.
• pmoveto(x, y): moves the screen cursor to the x,y position.
• pline(x1, y1, x2, y2 [,c]): draws a line from x1,y1 to x2,y2 using the fg color or the optional c color.
• plineto(x, y [,c]): draws a line from current position to x,y using the fg color or the optional c color.
• pset(x, y [,c]): draws a pixel at position x,y using the fg color or the optional c color.
• pget(x, y): return a number with the color of pixel at position x,y.
• prect(x, y, dx, dy [,c]): draws a rectangle at x,y, extending dx,dy pixels, using the fg color or the optional c color.
• pbox(x, y, dx, dy [,c]): draws a filled rectangle at x,y, extending dx,dy pixels, using the fg color or the optional c color.
• pcircle(x, y, rx, ry [,c]): draws an ellipse centered at x,y, with rx,ry as x,y radius, using the fg color or the optional c color. Use rx=ry for a circle.
• pdisc(x, y, rx, ry [,c]): draws a filled ellipse centered at x,y, with rx,ry as x,y radius, using the fg color or the optional c color. Use rx=ry for a filled circle.
• pfont(f): sets the text font to number f. Returns two numbers with the "average" width of a character and the height of a character, both in pixels. Note that PalmOS fonts are not fixed-width fonts, so if the returned width is used in calculations, you get just an approximation.
• pheading(g): turns the graphical "turtle" to the specified heading g (in degrees). 0 points to the right, 90 points up, and so on. Returns nothing.
• pturn(g): turns the graphical "turtle" g degrees. g can be positive or negative and it is added to the current heading. Returns nothing.
• pwalk(d): draws a line from the current cursor position, with extent d and following the current "turtle" heading. The cursor is positioned at the end of the line. Returns nothing.
