Examples (OpenGL and GLSL shaders) and complete OpenGL installation with w64devkit development kit, glad, glfw3 binaries, and Ninja building tool.
The objective of this repository is to simplify the development of OpenGL applications in C and C++. The advantage of using w64devkit is that it's a development kit that is portable, that is, that can be used just copying the files to any device in a Windows PC (an SD card, for example - not advisable). It does not require installation and bypasses the registry.
The development kit is used in normal command windows. To avoid typing and to simplify the overall development process the programs are built using Ninja building tool. Ninja is a very simple buiding tool that substitute makefiles with several advantages, particularly of being very efficient.
In this implementation GLFW and Glad are used, and all exemples are to be built with C compiler using this configuration. The examples are located inside glfw-3.3.8 directory, because they use GLFW library. The first two examples were downloaded from the web and modified for the installed configuration. The third example is a C++ example rewritten in C, with objective to simplify GLSL shader programming. For that a vertex shader with two triangles forming a rectangle (quad) is implemented to be used to display fragment shaders inside.
In shaders directory, the examples use a modified version of the third example. For example, the rectangle (quad) is expanded to the size of the viewport in order to show the fragment shaders in full window. The objective here is to implement in C, fragment shaders previously developed using web shader editors.
The fragment shaders developed on Shadertoy online shader editor can be used here with only few modifications.
Download this repository, for example, in the zip format and copy its content into an Explorer window located at the place chose to store the development kit as well as the other tools to be used. Keep this Explorer window opened for further use below. This repository contain some empty directories that are placeholders for the software to be dowloaded as follows.
Alternatively, place the development kit somewhere else. For that, after copying this repository somewhere in the hard drive, just delete w64devkit directory, and set the environment path to the complete path of "w64devkit/bin."
This is the development kit allowing to develop C/C++ projects in Windows 64, without needing to install any Windows tools. The advantage of this kit is its simplicity, allowing to perfectly understand the main dependencies involved without the need of setting paths to libraries or include files.
One can download it here. Choose a release (here it's v1.18.0) and click on the link:
w64devkit-1.18.0.zip
Delete the directory w64devkit, download the version desired and copy w64devkit directory at its previous positon,
or in some other place of choice.
For the sake of simplification, one should set the path in order to allow the kit to be visible in a command shell and accessible via Ninja building tool.
For that, one needs to go to Control Panel > System > About > Advanced System Settings, select Environment Variables
on System Properties window. In User variables for Administrator click on Path and Edit.... In the new window
Edit environment variable click New. In the Explorer window where w64devkit was copied click twice on w64devkit,
and click twice on bin. Now copy the path shown on the top of the Explorer window and paste it in the window
Edit environment variable, by clicking on New again and pasting. Press OK in this window, in Environment Variables window, as well as in System Properties.
The development kit is now installed and accessible in command shell windows, such as in a Windows Powershell
Find the latest release of Ninja here and click on:
ninja-win.zip
Copy ninja.exe from the zip file to the tools directory
Now set a new path to the tools directory.
Go to Control Panel > System > About > Advanced System Settings, select Environment Variables
on System Properties window. In User variables for Administrator click on Path and Edit.... In the new window
Edit environment variable click New. In the Explorer window where ninja.exe was copied copy the path shown on the
top of the Explorer window and paste it in the window Edit environment variable, by clicking on New again and pasting.
Press OK in this window, in Environment Variables window, as well as in System Properties.
Now Ninja is visible to any command shell window
This library is already installed in this repository for convenience. The whole package can be downloaded
here and clicking on 64-bit Windows binaries. If a new version of
glfw is required than the whole package should be reinstalled.
For simplicity, the installation of glfw-3.3.8 as provided in this repository is explained as follows.
Glad is an OpenGL library loader and it's used here as well as in other open source programs.
Glad is already provided in this repository. All we need is to compile it. For that, go to glad subdirectory and
in a command shell opened in this location, just type:
ninja
This will read the file build.ninja which gives the details on how to compile Glad. It will generate
the file glad.o that will be needed to be linked to any OpenGL program using the approach shown here.
Returning to the glfw-3.3.8 directory, one should now be able to compile the examples. For that, open
a command shell in this location, and just type:
ninja
Example 2 is a modified version of the source code shown here. It
uses the library linmath.h, which is all contained in that include file (functions are #define macros). This include
file is located here.
Example 3 is a C++ example rewritten in C, with objective to simplify GLSL shader programming. For that a vertex shader with two triangles forming a rectangle (quad) is implemented to be used to display fragment shaders inside.
In shaders directory, the examples use a modified version of the third example. For example, the rectangle (quad) is expanded to the size of the viewport in order to show the fragment shaders in full window. The objective here is to implement in C, fragment shaders previously developed using web shader editors.
To compile these examples one uses a separate Ninja build called ttf.ninja. To build the examples one needs to type
ninja -f ttf.ninja
Notice that all Ninja build files and executable that are generated with these builds will be located in glfw-3.3.8 directory.
One can now execute the examples by calling in the command shell the correspondent executable (.exe) program name. For example, supposing the executable name program.exe, one should type:
./program
No executable is called program. Just substitude program by the executable names in this directory as many as there are available.
And this tests the installation.
In addition to these examples, Ninja will build additional examples found in shaders directory. These examples have more specific names as can be seen from the executable filenames. These are called in a similar way as explained above.
These additional examples are for GLSL shader development, as a way to help implementing in C language, GLSL fragment shaders previously developed in online GLSL shader editors such as Shadertoy.
TrueType Glyphs Display examples are more specific examples to diplay TrueType glyphs using shaders.
As explained above the whole glfw package can be downloaded here and clicking on
64-bit Windows binaries. One can copy the new version in a new directory at the level of the directories w64devkit
and tools.
The directory glfw-3.3.8 should be conserved at least for conserving a clean copy until the new installation is
working fine. Once the new glfw directory is copied, one should then copy all necessary files from glfw-3.3.8 to
this new directory. These are the example source files, build.ninja and the entire glad directory. For example2
one should also copy linmath.h.
In principle the build.ninja doen't need to be modified, since there are no instances of glfw-3.3.8 in it.
If one needs to change the locations of the different parts of this installation, then the build.ninja and
the different paths might be required to be changed, accordingly.
As can be seen, build.ninja files are quite simple to understand and modified.
Glad will also be required to change in certain cases. This can be done by generating the file
based on the official specs. It's set to C/C++ language by default. The gl version used here was 4.2 and we should
make sure to also choose core compatibility. The Option Generate a loader also has to be checked. By clicking on
Generate one is presented with a zip file containing the directoties to be copied to glad directory.