GameMaker GML: Optimized Text Outline Functions

draw_text_outline.gml

#macro THICKNESS 1

/**
 * Draws text with an outline effect by rendering the text multiple times
 * with slight offsets before drawing the main text on top.
 *
 * @param {real} _x - X position to draw the text
 * @param {real} _y - Y position to draw the text
 * @param {string} _text - The text string to draw
 * @param {color} _textColor - Color of the main text (default: white)
 * @param {real} _outlineThickness - Thickness of the outline in pixels (default: THICKNESS macro)
 * @param {color} _outlineColor - Color of the outline (default: black)
 *
 * @example
 * // Draw white text with black outline
 * draw_text_with_outline(100, 100, "Hello World!", c_white, 2, c_black);
 *
 * // Draw red text with yellow outline using default thickness
 * draw_text_with_outline(200, 200, "Score: 1000", c_red, THICKNESS, c_yellow);
 */
function draw_text_with_outline(_x, _y, _text, _textColor = c_white, _outlineThickness = THICKNESS, _outlineColor = c_black) {

    // Convert text to handle newlines properly
    var processed_text = string_hash_to_newline(_text);

    // Set outline color once before drawing all outline instances
    draw_set_color(_outlineColor);

    // Draw outline by rendering text at offset positions around the main position
    // This creates a uniform outline effect in all directions
    for (var offset_x = -_outlineThickness; offset_x <= _outlineThickness; offset_x++) {
        for (var offset_y = -_outlineThickness; offset_y <= _outlineThickness; offset_y++) {
            // Skip the center position (0,0) as that's where the main text will be drawn
            if (offset_x != 0 || offset_y != 0) {
                draw_text(_x + offset_x, _y + offset_y, processed_text);
            }
        }
    }

    // Draw the main text on top of the outline
    draw_set_color(_textColor);
    draw_text(_x, _y, processed_text);
}

/**
 * Alternative optimized version that draws outline in 8 directions only
 * More performance-friendly for thicker outlines
 *
 * @param {real} _x - X position to draw the text
 * @param {real} _y - Y position to draw the text
 * @param {string} _text - The text string to draw
 * @param {color} _textColor - Color of the main text (default: white)
 * @param {real} _outlineThickness - Thickness of the outline in pixels (default: THICKNESS macro)
 * @param {color} _outlineColor - Color of the outline (default: black)
 */
function draw_text_with_outline_optimized(_x, _y, _text, _textColor = c_white, _outlineThickness = THICKNESS, _outlineColor = c_black) {

    var processed_text = string_hash_to_newline(_text);

    // Set outline color
    draw_set_color(_outlineColor);

    // Draw outline in 8 directions (cardinal + diagonal)
    // Top row
    draw_text(_x - _outlineThickness, _y - _outlineThickness, processed_text); // Top-left
    draw_text(_x, _y - _outlineThickness, processed_text);                     // Top
    draw_text(_x + _outlineThickness, _y - _outlineThickness, processed_text); // Top-right

    // Middle row (skip center)
    draw_text(_x - _outlineThickness, _y, processed_text);                     // Left
    draw_text(_x + _outlineThickness, _y, processed_text);                     // Right

    // Bottom row
    draw_text(_x - _outlineThickness, _y + _outlineThickness, processed_text); // Bottom-left
    draw_text(_x, _y + _outlineThickness, processed_text);                     // Bottom
    draw_text(_x + _outlineThickness, _y + _outlineThickness, processed_text); // Bottom-right

    // Draw main text
    draw_set_color(_textColor);
    draw_text(_x, _y, processed_text);
}