text-mode

The goal of the text-mode DUB package is to be a virtual text-mode, like in older DOS machines, except with Unicode support instead of a single 8-bit code page. There is however a 16 color palette like in ancient text modes.

A secundary goal is to be efficient (everything is cached) and provide vintage looks.

0. Basic example

See examples/ to run a basic example (you will need SDL installed).

1. Setup a TM_Console

The following TM_Console methods are necessary in order to use text-mode:

• size(int columns, int rows)
• outbuf(void* p, int width, int height, int pitchBytes)
• render()

Example:

TM_Console console;

void setup(MyImage image)
{
    // Set number of columns and rows.
    int columns = 40;
    int rows = 20;
 
    // .size clear the text buffer content and eventually resize it
    console.size(columns, rows);
 
    // set where to draw output, can be called every frame
    console.outbuf(image.ptr, image.width, image.height, image.pitchBytes);
 
    /* ...printing functions goes here... */
 
    // display changes since the last .render, in output buffer
    console.render();
}

Key concept: No font resampling is done. Pixels are scaled NxN depending to the room in output buffer, and letterboxed with "border" pixels.

2. Print some text

Example:

console.size(40, 22);

with (console)
{
    cls();
 
    print("Hello world! ");
    println("Same, with line feed");
 
    // Save state (colors, style, cursor position)
    save();
 
    // Change foreground color (0 to 15)
    fg(TM_red);
    print("This is red text ");
    bg(TM_blue);
    println("on blue background");
 
    // Restore state. Warning: this restore cursor position!
    restore();
 
    // Set text cursor position (where text is drawn next)
    locate(7, 5);
 
    // There are 3 implemented styles:
    //   - bold
    //   - shiny (sort of bloom)
    //   - underline
    style(TM_bold);
    println("This is bold");
 
    style(TM_shiny);
    print("This is ");
    fg(14);
    println("shiny");
 
    style(TM_underline);
    fg(TM_lgreen);
    println("This is underline");
 
    render();
}

Result

Key-concept: if text must be printed in a line below the screen, the whole screen scrolls.

4. REXPaint .xp file support

REXPaint is a ANSI art editor that introduced the .xp file as data format. Use printXP to display a .xp file at the cursor position.

import std.file;
auto xpBytes = std.file.read("resources/xp-format.xp");
console.locate(x, y);
console.printXP(xpBytes);

Result

See the ans-display

There is also support for .ans file encoded in CP-437 or UTF-8 with the functions: printANS() and printANS_CP437().

5. CCL Language

cprint and cprintln accepts markup language.

Accepted:

• Foreground color: <black>, <red>, <green>, <orange>, <blue>, <magenta>, <cyan>, <lgrey>, <grey>, <lred>, <lgreen>, <yellow>, <lblue>, <lmagenta>, <lcyan>, <white>
• Background color: <on_black>, <on_red>, <on_green>, <on_orange>, <on_blue>, <on_magenta>, <on_cyan>, <on_lgrey>, <on_grey>, <on_lred>, <on_lgreen>, <on_yellow>, <on_lblue>, <on_lmagenta>, <on_lcyan>, <on_white>
• Bold: <b>, <strong>
• Underlined: <u>
• Shiny: <shiny>
• Blinking: <blink>

Example:

console.size(40, 22);
with (console)
{
    cls();
    cprintln("<b>This is bold</b>");
    cprint("Special character: &lt; &gt; &amp;")
}

6. Changing console options

TM_Console console;
console.size(40, 22);

// You can change options at any time, everything is lazy.
TM_Options opt;
opt.blinkTime = 600; // See all options below
console.options(opt

Here is reproduced the definition of TM_Options:

/// Various options to change behaviour of the library.
struct TM_Options
{
    TM_BlendMode blendMode = TM_BlendMode.sourceOver; ///
    TM_HorzAlign halign    = TM_HorzAlign.center; ///
    TM_VertAlign valign    = TM_VertAlign.middle; ///

    /// The output buffer is considered unchanged between calls.
    /// It is considered our changes are still there and not erased,
    /// unless the size of the buffer has changed, or its location.
    /// In this case we can draw less.
    bool allowOutCaching   = false;

    /// Palette color of the borderColor;
    ubyte borderColor      = 0;

    /// Is the border color itself <shiny>?
    bool borderShiny       = false;

    /// The <blink> time in milliseconds.
    double blinkTime = 1200;


    // <blur>

    /// Quantity of blur added by TM_shiny / <shiny>
    /// (1.0f means default).
    float blurAmount       = 1.0f;

    /// Kernel size in multiple of default value.
    /// This changes the blur filter width (1.0f means default).
    float blurScale        = 1.0f;

    /// Whether foreground/background color contributes to blur.
    bool blurForeground    = true;
    bool blurBackground    = true; ///ditto

    /// Luminance blue noise texture, applied to blur effect.
    bool noiseTexture      = true;

    /// Quantity of that texture (1.0f means default).
    float noiseAmount      = 1.0f;

    // </blur>


    // <tonemapping>

    /// Enable or disable tonemapping.
    bool tonemapping       = false;

    /// Channels that exceed 1.0f, bleed that much in other channels.
    float tonemappingRatio = 0.3f;

    // </tonemapping>
}

7. Direct character data access

If you'd like to not go through print/println then you can access character data with charAt.

TM_Console console;
console.size(40, 22);
console.charAt(0, 0).glyph = '╚';
console.charAt(0, 0).color = 0x02 + 0x70;
console.charAt(0, 0).style = 0;

.charAt return a ref TM_CharData.