Standard ML API for TIGR - the TIny GRaphics library

sml-tigr

Standard ML package for interfacing with TIGR - the TIny GRaphics library, which is a small graphics library that works on both Linux and macOS platforms. In particular, this package contains bindings for the MLKit (> v4.7.8).

Notice that this repository is a fork of the repository for TIGR - the TIny GRaphics library - with an added Standard ML API for the library.

Overview of MLB files

• lib/github.com/diku-dk/sml-tigr/tigr.mlb:

  • signature TIGR
  • structure Tigr : TIGR

Use of the package

The repository is set up to work well with the SML package manager smlpkg. To use the package, in the root of your project directory, execute the command:

$ smlpkg add github.com/diku-dk/sml-tigr

This command will add a requirement (a line) to the sml.pkg file in your project directory (and create the file, if there is no file sml.pkg already).

To download the library into the directory lib/github.com/diku-dk/sml-tigr, execute the command:

$ smlpkg sync

You can now reference the mlb-file using relative paths from within your project's mlb-files.

Notice that you can choose either to treat the downloaded package as part of your own project sources (vendoring) or you can add the sml.pkg file to your project sources and make the smlpkg sync command part of your build process.

Before compiling a project that uses tigr.mlb, the compilation process must be set up first to generate a dynamic library for TIGR (the file libtigr.so) and then to link with the dynamic library at program launch. You may use the target lib in Makefile to generate the libtigr.so dynamic library. To see an example of how to setup MLKit to link with the dynamic library, consult Makefile.

Standard ML Examples

Standard ML examples include the hello and flags examples ported to Standard ML from C, the mandel example demonstrating an interactive Mandelbrot viewer, the nbody example demonstrating an interactive Nbody simulator, and the ray example demonstrating dynamic ray-tracing.

The C Library (from https://github.com/erkkah/tigr)

TIGR is a tiny cross-platform graphics library, providing a unified API for Windows, macOS, Linux, iOS and Android.

TIGR's core is a simple framebuffer library. On top of that, TIGR provides a few helpers for the common tasks that 2D programs generally need:

• Bitmap-backed windows.
• Direct access to bitmaps, no locking.
• Basic drawing helpers (plot, line, blitter).
• Text output using bitmap fonts.
• Mouse, touch and keyboard input.
• PNG loading and saving.
• Easy pixel shader access.

TIGR is designed to be small and independent. The 'hello world' example is less than 100kB:

Platform	Size
windows x86_64	48k
linux x86_64	43k
macOS arm64	90k
macOS x86_64	74k

There are no additional libraries to include; everything is baked right into your program.

TIGR is free to copy with no restrictions; see tigr.h.

How do I program with TIGR?

Here's an example Hello World program in C. For more information, just read tigr.h to see the APIs available.

#include "tigr.h"

int main(int argc, char *argv[])
{
    Tigr *screen = tigrWindow(320, 240, "Hello", 0);
    while (!tigrClosed(screen))
    {
        tigrClear(screen, tigrRGB(0x80, 0x90, 0xa0));
        tigrPrint(screen, tfont, 120, 110, tigrRGB(0xff, 0xff, 0xff), "Hello, world.");
        tigrUpdate(screen);
    }
    tigrFree(screen);
    return 0;
}

How to set up TIGR

Desktop (Windows, macOS, Linux)

TIGR is supplied as a single .c and corresponding .h file.

To use it, you just drop them right into your project.

1. Grab tigr.c and tigr.h
2. Throw them into your project.
3. Link with
   • -lopengl32 and -lgdi32 on Windows
   • -framework OpenGL and -framework Cocoa on macOS
   • -lGLU -lGL -lX11 on Linux
4. You're done!

Android

Due to the complex lifecycle and packaging of Android apps (there is no such thing as a single source file Android app), a tiny wrapper around TIGR is needed. Still - the TIGR API stays the same!

To keep TIGR as tiny and focused as it is, the Android wrapper lives in a separate repo.

To get started on Android, head over to the TIMOGR repo and continue there.

iOS

On iOS, TIGR is implemented as an app delegate, which can be used in your app with just a few lines of code.

Building an iOS app usually requires quite a bit of tinkering in Xcode just to get up and running. To get up and running fast, there is an iOS starter project with a completely commandline-based tool chain, and VS Code configurations for debugging.

To get started on iOS, head over to the TIMOGRiOS repo and continue there.

NOTE: TIGR is included in TIMOGR and TIMOGRiOS, there is no need to install TIGR separately.

Fonts and shaders

Custom fonts

TIGR comes with a built-in bitmap font, accessed by the tfont variable. Custom fonts can be loaded from bitmaps using tigrLoadFont. A font bitmap contains rows of characters separated by same-colored borders. TIGR assumes that the borders use the same color as the top-left pixel in the bitmap. Each character is assumed to be drawn in white on a transparent background to make tinting work.

Use the tigrfont tool to create your own bitmap fonts from TTF or BDF font files.

Since TIGR version 3.1, unicode-encoded font sheets are supported, making it possible to render any glyph in your fonts. Text is still just rendered LTR, though.

Custom pixel shaders

TIGR uses a built-in pixel shader that provides a couple of stock effects as controlled by tigrSetPostFX. These stock effects can be replaced by calling tigrSetPostShader with a custom shader. The custom shader is in the form of a shader function: void fxShader(out vec4 color, in vec2 uv) and has access to the four parameters from tigrSetPostFX as a uniform vec4 called parameters.

See the shader example for more details.

Known issues

On macOS, seemingly depending on SDK version and if you use TIGR in an Xcode project, you need to define OBJC_OLD_DISPATCH_PROTOTYPES to avoid problems with objc_msgSend prototypes.