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get-image-glsl

This program renders a fragment shader, it can be compiled with different context provider, currently EGL or GLFW. See build instructions below.

Prerequisites

The following are required for building and running the tool:

• The OpenGL headers (in Ubuntu, provided by mesa-common-dev)
• GLFW (in Ubuntu, provided by libglfw-3-dev)
• CMake

Usage

Note: For an up-to-date option overview, just run one of the executables without any arguments, it should list its options.

Usage: ./get_image_<egl/glfw> [options] shader.frag

The program will look for a JSON whose name is derived from the
shader as '<shader>.json'. This JSON file can contain uniforms
initialisations. If no JSON file is found, the program uses default
values for some uniforms.

Options are:
  --delay                            number of frames before PNG capture
  --exit-compile                     exit after compilation
  --exit-linking                     exit after linking
  --output file.png                  set PNG output file name
  --resolution <width> <height>      set viewport resolution, in Pixels
  --vertex shader.vert               use a specific vertex shader
  --dump_bin <file>                  dump binary output to given file

Return values:
  0    Successful rendering
  1    Error
  101  Shader compilation error (either fragment or vertex)
  102  Shader linking error

Build

The EGL version requires that you copy libEGL and libGLESv2 into deps/. See below for skipping the EGL version.

Linux

Using CMake manually:

mkdir b
cd b
cmake -G "Unix Makefiles" .. -DCMAKE_BUILD_TYPE=Release
cmake --build . --config Release
cmake -DCMAKE_INSTALL_PREFIX=../install -DBUILD_TYPE=Release -P cmake_install.cmake

Or, use the script.

cd build
./build-linux

Alternatively, if you already have glfw3 and egl installed, you can use the Makefile (just call make).

Windows

Using CMake manually:

mkdir b
cd b
cmake -G "Visual Studio 14 2015 Win64" .. -DCMAKE_BUILD_TYPE=Debug
cmake --build . --config Debug
cmake -DCMAKE_INSTALL_PREFIX=../install -DBUILD_TYPE=Debug -P cmake_install.cmake

Or, use this cross-compilation script from Linux:

cd build
./build-x86_64-w64-mingw32

Skipping version

Skip building certain versions as follows. E.g.

cmake -G "Unix Makefiles" .. -DBUILD_GLFW_VERSION=OFF -DBUILD_EGL_VERSION=OFF
                               ^ (skip GLFW version)    ^ (skip EGL version)

Developer notes

TODO

• add option to force a particular opengl api version (with glfw)

Crash early!

For any error, use the crash() macro defined in common.h. Do not hesitate to crash as soon as something goes wrong, rather than passing around return values.

CI

• Windows: See appveyor.yml and the corresponding scripts under buildscripts/

There is a dependency on:

# see buildscripts/1-install-deps-appveyor.sh
https://github.com/paulthomson/github-release