Michael Conrad

NAME

OpenGL::Sandbox - Rapid-prototyping utilities for OpenGL

VERSION

version 0.03

EXPORTS

GL_$CONSTANT, gl$Function

This module can export OpenGL constants and functions, selecting them out of either OpenGL or OpenGL::Modern. When exported by name, constants will be exported as true perl constants. However, the full selection of GL constants and functions is *not* available directly from this module's namespace. i.e. OpenGL::Sandbox::GL_TRUE() does not work.

$res

Returns a default global instance of the resource manager with resource_root_dir pointing to the current directory.

tex

Shortcut for OpenGL::Sandbox::ResMan->default_instance->tex

font

Shortcut for OpenGL::Sandbox::ResMan->default_instance->font

Note that you need to install OpenGL::Sandbox::V1::FTGLFont in order to get font support, currently. Other font providers might be added later.

:V1:all

Exports ':all' from OpenGL::Sandbox::V1 (which must be installed separately). This module contains many "sugar" functions to make the GL 1.x API more friendly.

:V2:all, :V3:all, etc will likewise import everything from packages named OpenGL::SandBox::V$_ which do not currently exist, but could be authored in the future.

make_context

  my $context= make_context( %opts );

Pick the lightest smallest module that can get a window set up for rendering. This tries: X11::GLX, and SDLx::App in that order. You can override the detection with environment variable OPENGL_SANDBOX_CONTEXT_PROVIDER. It assumes you don't have any desire to receive user input and just want to render some stuff. If you do actually have a preference, you should just invoke that package yourself.

Always returns an object whose scope controls the lifecycle of the window, and that object always has a swap_buffers method.

This attempts to automatically pick up the window geometry, either from a "--geometry=" option or from the environment variable OPENGL_SANDBOX_GEOMETRY. The Geometry value is in X11 notation of "${WIDTH}x${HEIGHT}+$X+$Y" except that negative X,Y (from right edge) are not supported.

Not all options have been implemented for each source, but the list of possibilities is:

x, y, width, height

Set the placement and dimensions of the created window.

visible

Defaults to true, but if false, attempts to create an off-screen GL context.

fullscreen

Attempts to create a full-screen context.

noframe

Attempts to create a window without window border decorations.

title

Window title

Note that if you're using Classic OpenGL (V1) you also need to set up the projection matrix to something more useful than the defaults before rendering anything. See "setup_projection" in OpenGL::Sandbox::V1.

get_gl_errors

Returns the symbolic names of any pending OpenGL errors, as a list.

INSTALLING

Getting this module collection installed is abnormally difficult. This is a "selfish module" that I wrote primarily for me, but published in case it might be useful to someone else. My other more altruistic modules aim for high compatibility, but this one just unapologetically depends on lots of specific things.

For the core module, you need:

  • Perl 5.14 or higher

  • libGL, and headers

  • LibAV libraries libswscale, libavutil, and headers, for the feature that automatically rescales textures

  • Image::PNG::Libpng, for the feature that automatically loads PNG.

  • File::Map, for efficiently memory-mapping resource files

  • Inline::C, including a local C compiler

For the "V1" module (OpenGL::Sandbox::V1) you will additionally need

  • libGLU and headers

  • Inline::CPP, including a local C++ compiler

For the "FTGLFont" module (OpenGL::Sandbox::V1::FTGLFont) you will additionally need

  • libftgl, and libfreetype2, and headers

You probably also want a module to open a GL context to see things in. This module is aware of X11::GLX and SDL, but you can use anything you like since the GL context is global.

AUTHOR

Michael Conrad <mike@nrdvana.net>

COPYRIGHT AND LICENSE

This software is copyright (c) 2018 by Michael Conrad.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.