Commander X16

When used with keyboard or SNES game-pad controls the COLORSKETCH application is somewhat analogous to an "Etch-A-Sketch" device but with support for assigning colors to the pen and toggling the pen state "on/off". When used with mouse controls COLORSKETCH is more akin to a primitive drawing/painting program.

COLORSKETCH supports a resolution of 320x240 pixels at 8-bit color and is currently compatible with revision R37 of the Commander X16 emulator. COLORSKETCH also provides the ability to edit the RGB values of the color palette (except for color index 0 which corresponds to transparent). COLORSKETCH supports two primary modes of operation including sketch mode and color selection mode which are described below.

Sketch Mode:

In sketch mode the space bar toggles the "on/off" state of the pen which defaults to "off" when COLORSKETCH is started. When the pen state is "off" a pointer appears on the screen to show the current location of the cursor. When the pen state is toggled "on" the cursor pointer is turned off and the pixel at the current cursor location is populated with the currently selected color. The Arrow keys (and also "WSAD" keys) are used to move the cursor vertically and horizontally between pixels, and the "QEZX" keys are used to move diagonally between pixels. When the pen state is "on" the currently selected color is populated in all pixels visited as the cursor is moved.

In sketch mode the "B" key may be used to toggle the pen between the layer 0 background color (which is selected at startup as described further below) and the currently selected color. This capability is intended as a means to quickly address/erase mistakes.

In sketch mode the "F1" key may be used to toggle the display of the cursor coordinates between the top left of the screen (which is the default when COLORSKETCH is started), top right of the screen, and off.

In sketch mode the "F3" and "F4" keys may also be used to cycle the layer 1 foreground and background colors used for the display of the cursor coordinates mentioned above and in the color selection mode menu described below. The layer 1 foreground color also affects the color of the cursor pointer described above. The layer 1 foreground and background colors can be set to any of the first 16 entries in the color palette except the layer 1 background color can not be set to index 0 (which corresponds to transparent).

 The "C" key is used to enter color selection mode which is described below.

Color Selection Mode:

In color selection mode the color palette is organized into 16 rows where each row contains 16 colors, and only a single row of the color palette is displayed at the top of the screen. The left and right arrow keys (and also "A/D" keys) are used to move between colors in the same row, and the up/down arrow keys (and also "W/S" keys) are used to move between rows of the color palette. The currently selected color is underlined and the left side of the color selection mode screen displays information including the color index and the RGB values of the currently selected color. The RGB values of the currently selected color may be edited using the "R/r", "G/g", and "B/b" keys (except the transparent color associated with index 0). The "0" key may be used to navigate directly to the first entry in the color palette (with index 0). When the Enter key is pressed the currently selected color is assigned to the pen and color selection mode is exited transferring control back to sketch mode described above. Color selection mode may also be exited by pressing the "Q" key which retains any changes made to the color palette but does not affect the currently selected color.

Sketch Mode Background Color:

When COLORSKETCH is started it initially enters color selection mode described above to select a layer 0 background color for sketch mode which defaults to index 0 which corresponds to transparent.

Controller Support:

COLORSKETCH supports the SNES controller when the emulator is started with the "-joy1 SNES" option. The D-pad is supported in color selection mode as well as sketch mode. When attempting to draw a diagonal line in sketch mode many times one of the D-pad controls activates before the other one. To address this issue the right or left bumper may be depressed and held down and then the up or down D-pad control may be depressed in order to draw a diagonal line. In sketch mode the SNES controller "A" button is used to toggle the pen state "on/off", the "B" button is used to toggle between the layer 0 background color and the currently selected color, and the "X" button may be used to enter color selection mode. In color selection mode the "Y" button is used to return to sketch mode.

Mouse Support:

I haven't found mouse support to be particularly smooth or reliable in the Commander X16 emulator at this point so COLORSKETCH provides the ability to toggle the mouse "on/off" with the "M" key. The mouse defaults to "off". When the mouse is turned "on" the left mouse button is used to control the pen. In mouse mode the cursor is always visible. When using the mouse to draw (with the left mouse button depressed) it is advisable to move the mouse slowly in order to color all pixels visited by the mouse. The mouse is only used in sketch mode and is disabled in color selection mode both of which are described above. At times the mouse seems to be restricted to a subset of the Commander X16 emulator screen and in this case sometimes the problem can be resolved by moving the mouse all the way to the left, right, top, and bottom sides of the entire monitor screen and then moving the mouse back into the window associated with the Commander X16 emulator.

The cursor and SNES game pad controls provide more precise control than mouse controls. For example the cursor and SNES game pad controls can be used to draw perfectly horizontal, vertical, and diagonal lines. The option to display cursor coordinates also provides the ability to achieve exactness with respect to the placement and dimensions of drawn objects.

It's desirable to add support for saving/loading of the sketch and color palette data to/from disk files but unfortunately Revision R37 of the Commander X16 emulator doesn't support file input/output to disk.

Added .PRG extension to the file name in attempt to support web emulator "Try it now" feature.