PHP-GLFW

Write fun 3D / 2D games or other graphical applications with PHP! This is a C extension that adds GLFW & OpenGL support to PHP.

❓❓❓

Keep in mind this is a gif in reality this runs smoothly at 60fps.

Notes / Disclaimer

Nobody asked for a library like this, and still, I delivered. Please don't spend a tremendous amount of time writing a "real game" in PHP with this. Just because its possible does not mean it is a good idea. I have no idea how you would ship/distribute such a game. Therefore this library hopefully serves an educational purpose for people who want to get into graphics programming and mainly work with PHP.

I am very far from being an expert with the Zend engine and the PHP internals. So there are pieces in this code that will make you want to pull out your hair from your head. My focus was to make this thing work at any cost, bugs, performance and memory leaks or even safe type conversions can be fixed later. (Or maybe never because again this is not supposed to create production applications with.) Many methods introduce a hell lot of overhead when it comes to copying or type conversations (I would love to buy you a beer here in Zürich if you can help me make this somehow efficient.).

Also, keep in mind I did not spend time making this failsafe in any way. When you pass unexpected types / values, you might end up with a segmentation fault.

I can't point this out enough this library is far from stable, and should only be used in "just for fun" or "because I can" and general experimental type of projects. At least in its current state, who knows what the future brings.

Installation

Note: I only tested this extension on MacOS.

Make sure to install glfw3.

$ brew install glfw3

Clone the repository.

$ git clone https://github.com/mario-deluna/php-glfw/ && cd php-glfw

Now you should be able to build the extension:

$ phpize
$ ./configure --enable-glfw
$ make && make install

Don't forget to link the extension, by appending the following lines to your php.ini.

[glfw]
extension=glfw.so

Example (Triangle)

Drawing the classic colored triangle. You can run this example: php ./examples/triangle.php

Code:

<?php

// initalize GLFW
glfwInit();
echo glfwGetVersionString() . PHP_EOL;

// configure the window
glfwWindowHint(GLFW_RESIZABLE, GL_TRUE);
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

// fix for "el capitan"
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);

// create the window
if (!$window = glfwCreateWindow(800, 800, "PHP GLFW Demo")) {
    die('Could not create window.');
}

// setup the window
glfwMakeContextCurrent($window);
glfwSwapInterval(1);

/**
 * Shader Setup
 */
// Vertext shader
$vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource($vertexShader, 1, "
#version 330 core
layout (location = 0) in vec3 position;
layout (location = 1) in vec3 color;

out vec4 pcolor;

void main()
{
    pcolor = vec4(color, 1.0f);
    gl_Position = vec4(position, 1.0f);
}
");
glCompileShader($vertexShader);
glGetShaderiv($vertexShader, GL_COMPILE_STATUS, $success);

if (!$success) {
    die("Vertex shader could not be compiled.");
}

// fragment shaders
$fragShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource($fragShader, 1, "
#version 330 core
out vec4 fragment_color;
in vec4 pcolor;

void main()
{
    fragment_color = pcolor;
} 
");
glCompileShader($fragShader);
glGetShaderiv($fragShader, GL_COMPILE_STATUS, $success);

if (!$success) {
    die("Fragment shader could not be compiled.");
}

// link the shaders
$shaderProgram = glCreateProgram();
glAttachShader($shaderProgram, $vertexShader);
glAttachShader($shaderProgram, $fragShader);
glLinkProgram($shaderProgram);

glGetProgramiv($shaderProgram, GL_LINK_STATUS, $linkSuccess);

if (!$linkSuccess) {
    die("Shader program could not be linked.");
}

// free the shders
glDeleteShader($vertexShader);
glDeleteShader($fragShader);

/**
 * Vertex creation
 */
// Buffers
$VBO; $VAO; 

// verticies
$verticies = [ 
     // positions      // colors
    0.5, -0.5, 0.0,  1.0, 0.0, 0.0,  // bottom right
   -0.5, -0.5, 0.0,  0.0, 1.0, 0.0,  // bottom let
    0.0,  0.5, 0.0,  0.0, 0.0, 1.0   // top 
];

glGenVertexArrays(1, $VAO);
glGenBuffers(1, $VBO);

glBindVertexArray($VAO);

glBindBuffer(GL_ARRAY_BUFFER, $VBO);
glBufferDataFloat(GL_ARRAY_BUFFER, $verticies, GL_STATIC_DRAW);

// positions
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6, 0);
glEnableVertexAttribArray(0);

// colors
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6, 3);
glEnableVertexAttribArray(1);

// unbind
glBindBuffer(GL_ARRAY_BUFFER, 0); 
glBindVertexArray(0); 

/**
 * Main loop
 */
while (!glfwWindowShouldClose($window))
{
    glClearColor(0, 0, 0, 1);
    glClear(GL_COLOR_BUFFER_BIT);

    // use the shader
    glUseProgram($shaderProgram);

    // draw our vertex array
    glBindVertexArray($VAO);
    glDrawArrays(GL_TRIANGLES, 0, 3);

    // swap
    glfwSwapBuffers($window);
    glfwPollEvents();
}

// stop & cleanup
glDeleteVertexArrays(1, $VAO);
glDeleteBuffers(1, $VBO);

glfwDestroyWindow($window);

glfwTerminate();

Whats inside?

This extension does not only deliver glfw and OpenGL bindings, but it also comes with stb_image to make getting started easy.

API Differences

I have tried to keep the API as similar as possible to the original C API of glfw and OpenGL, but I had to change some things to make this work quickly with PHP.

GLFW

glfwMakeContextCurrent

This method will automatically load the glad function pointers.

OpenGL

glShaderSource

The last argument the length has been removed from the glShaderSource function. When you want to add multiple, simply use null termination, or just call the method multiple times.

glBufferData

The glBufferData method has been disabled and is replaced with multiple type specific buffer methods:

glBufferDataFloat
glBufferDataDouble
glBufferDataInt
glBufferDataLong

Also, you do not need to pass in the size of your data this is solved by the type-specific methods itself.

glBufferDataFloat(GL_ARRAY_BUFFER, [1.0, 0.5, 0.0], GL_STATIC_DRAW);

glVertexAttribPointer

In phpglfw, the stride (byte offset) and pointer offset of the vertex attributes is a pure number representing the count and not the size of the data. The size is then determined by the given type.

So this attribute pointer in C:

glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));

Would be written in php be:

glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 5, 3);

pkruczynski / php-glfw