glmff

OpenGL Mathematics For Fortran (GLMFF).

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This is a Fortran adaptation of the glm library. It is part of my Fortran Multimedia Framework Portability Project.

It contains most of the core features and works the same way as the well-known glm C++ library.

You only need to use the glmff module to access all the core functionalities:

program glmff_example
    use glmff

    implicit none
    type(mat4) :: mat, proj
    type(vec3) :: pos

    mat = mat4(1.0) ! Identity matrix
    pos = vec3(0.5, 1.0, 0.0)
    mat = translate(mat, pos) ! Build a translation matrix
    proj = perspective(radians(60), 0.25, 0.1, 100.0) ! Build a projection matrix
    ! ...
end program

Extensions have not been implemented yet.

It must be noted that the Fortran data types are not as fancy as the C++ ones. Instead of using unions and individual variables for each components (x, y, z / r, g, b, ...), the components of matrix and vector types are stored in an array. This is both because Fortran does not have any reliable union equivalent, and because Fortran inherently takes advantage of array structures to optimise calculations.

my_vec%data(1) = ... ! Set the X component
my_vec%data(2) = ... ! Set the Y component
my_vec%data = ... ! Set all components at once

The data component can then be passed directly to OpenGL functions.

Compilation

Unfortunately, Fortran is not an ABI-compatible language. This means that a precompiled binary of the library is not guaranteed to work unless it is used in the same environment with the same compiler. It is thus simpler to build your own version for your project in your environment.

This will require

• A Fortran compiler supporting the Fortran 2008 standard (GNU or Intel are most common)
• CMake

Clone this repository:

git clone https://github.com/gadjalin/glmff

On macOS and Linux

Use CMake to build:

cd glmff
cmake -B bin
cmake --build bin

The library and mod files are located in the bin and bin/src/mod directories.

On Windows

You may use CMake with tools such as Visual Studio or MinGW.

Include in your project

You can instead add glmff as a dependency in your CMake script

ADD_SUBDIRECTORY(path_to_glmff)
...
TARGET_LINK_LIBRARIES(... glmff ...)

Distribution

Except for macOS, you can compile a Fortran executable statically to facilitate distribution:

cmake -DBUILD_SHARE_LIBS=OFF -B bin
cmake --build bin

Fortran Multimedia Framework

• GLFW bindings: glf90w
• OpenGL bindings: glad-fortran
• OpenGL Mathematics: glmff