README

PHP extension for SDL3_image — image loading built with Zephir.

sdl3image wraps SDL3_image for PHP 8.2+, providing image decoding from common formats (PNG, JPG, WebP, and more) into SDL_Surface values, and texture loading into an existing SDL_Renderer.

Pair it with php-sdl/sdl3 for windowing, renderer creation, and event handling. Both extensions share the Sdl3* namespace prefix and can be loaded side-by-side.

Table of contents

• Requirements
• Installation
  • Via PHP PIE (recommended)
  • Platform installers
  • Manual build with phpize
• Verifying the install
• Quick start
• API reference
• Companion extension
• License

Requirements

Tested on macOS (Apple Silicon + Intel), Debian Trixie, Raspberry Pi OS (arm64 / armhf), and NVIDIA JetPack 6 (Jetson Orin).

Installation

Via PHP PIE (recommended)

Install php-sdl/sdl3 first, then install this extension:

pie install php-sdl/sdl3
pie install php-sdl/sdl3-image

PIE handles the full build pipeline (phpize → configure → make → install). Make sure SDL3 >= 3.4.0 and SDL3_image >= 3.2 are already installed on the system before running.

Platform installers

Three installer scripts live at the repository root. Each one installs SDL3 and SDL3_image if needed, builds the extension with Zephir, and enables it for detected PHP SAPIs.

macOS (Homebrew):

bash install-macos.sh

Debian Trixie / Raspberry Pi OS (amd64, arm64, armhf):

bash install-debian-trixie.sh

JetPack 6 / Ubuntu 22.04 (builds SDL3 + SDL3_image from source):

bash install-jetpack6.sh

Each script writes build output to ./build.log and prints concise diagnostics on failure.

Manual build with phpize

If generated C source exists in ext/, build without Zephir:

cd ext
phpize
./configure --enable-sdl3image
make -j"$(nproc 2>/dev/null || sysctl -n hw.logicalcpu)"
sudo make install

Then enable the extension:

; /etc/php/8.4/cli/conf.d/30-sdl3image.ini
extension=sdl3image.so

If SDL3 or SDL3_image is installed in a non-standard prefix, export PKG_CONFIG_PATH before ./configure.

Verifying the install

One-liner sanity check:

php -m | grep sdl3image

Expected output:

sdl3image

Quick start

<?php

use Sdl3image\SDLImage\IMG;

$surface = IMG::IMGLoad(__DIR__ . '/assets/logo.png');
if (empty($surface)) {
    fwrite(STDERR, "IMGLoad failed\n");
    exit(1);
}

printf(
    "Loaded image: %dx%d, pitch=%d, pixels=%d\n",
    $surface['w'],
    $surface['h'],
    $surface['pitch'],
    count($surface['pixels']['data'])
);

// Pass $surface['ptr'] into SDL3 renderer APIs from php-sdl/sdl3 as needed.

If you already have an SDL_Renderer pointer from php-sdl/sdl3, you can load directly into a texture via IMG::IMGLoadTexture($rendererPtr, $file).

API reference

All methods live on:

Sdl3image\SDLImage\IMG

IMGLoad(string $file): array

Loads an image file and returns an associative array describing an SDL_Surface.

Returns [] on failure.

[
    'ptr'      => int,   // SDL_Surface pointer
    'flags'    => int,   // surface flags
    'format'   => int,   // SDL pixel format enum
    'w'        => int,   // width in pixels
    'h'        => int,   // height in pixels
    'pitch'    => int,   // bytes per row
    'pixels'   => [
        'ptr'  => int,   // raw pixel buffer pointer
        'data' => int[], // packed 32-bit pixels in row-major order
    ],
    'refcount' => int,
]

IMGLoadTexture(int $renderer, string $file): array

Loads an image into an SDL_Texture for the given renderer pointer.

• $renderer is an SDL_Renderer* cast to integer, obtained via php-sdl/sdl3.
• Returns [] on failure.

[
    'ptr'      => int,   // SDL_Texture pointer
    'format'   => int,   // SDL pixel format enum
    'w'        => int,   // texture width
    'h'        => int,   // texture height
    'refcount' => int,   // currently fixed to 1
]

Companion extension

This extension focuses on image decoding/loading. For window creation, input, rendering, and the rest of SDL3, install php-sdl/sdl3 alongside it.

Both extensions can be loaded simultaneously with separate module names (sdl3 and sdl3image) and no conflict.

License

MIT © Project Saturn Studios, LLC.