scott created page: JoeyLib Drawing Functions

JoeyLib-Drawing-Functions.md

@@ -0,0 +1,61 @@
+*All drawing operations take place on a "back buffer" and not on the visible display.  To make any content visible, you must call `jlDisplayPresent()`.*
+
+#### jlDrawBlit8x8
+```c
+void jlDrawBlit8x8(jlStaT *sta, int cx1, int cy1, int cx2, int cy2);
+```
+"Blits" (rapidly copies) an 8x8 pixel "tile" from a loaded static image onto the back buffer.  The coordinates of the tile to blit are specified in "cells".  With the display being 320x200 pixels, there are 40x24 cells per image/display.
+
+#### jlDrawBox
+```c
+void jlDrawBox(int x1, int y1, int x2, int y2);
+```
+Draws a hollow rectangle from (x1, y1) to (x2, y2).
+
+#### jlDrawBoxFilled
+```c
+void jlDrawBoxFilled(int x1, int y1, int x2, int y2);
+```
+Draws a hollow rectangle from (x1, y1) to (x2, y2).
+
+#### jlDrawClear
+```c
+void jlDrawClear(void);
+```
+Clears the back buffer to the current draw color.
+
+#### jlDrawColor
+```c
+void jlDrawColor(byte index);
+```
+Specifies the color to use for the following draw functions.  Colors are specified by their index position in the current palette.
+
+#### jlDrawFill
+```c
+void jlDrawFill(int x, int y);
+```
+Performs a flood fill from the given coordinates.  The fill will continue as long as it occupies the same color as the starting point.
+
+#### jlDrawFillTo
+```c
+void jlDrawFillTo(int x, int y, byte color);
+```
+Performs a flood fill from the given coordinates.  The fill will continue until it encounters pixels of `color`.
+
+#### jlDrawGetPixel
+```c
+byte jlDrawGetPixel(int x, int y);
+```
+Returns the color index of the specified pixel.
+
+#### jlDrawLine
+```c
+void jlDrawLine(int x1, int y1, int x2, int y2);
+```
+Draws a line from (x1, y1) to (x2, y2).
+
+#### jlDrawPoint
+```c
+void jlDrawPoint(int x, int y);
+```
+Draws a single point at location (x, y).