Sun Jan 26 12:51:09 PM CET 2025

Author: emad-elsaid

Getting started with SDL2 and Go on Wayland.md

@@ -0,0 +1,72 @@
+#go
+
+* A [binding](https://github.com/veandco/go-sdl2) for SDL2 exists already for Go, so there is no need to use the C functions directly
+* A simple program to run a window and color it didn't work out of the box and `SDL_VIDEODRIVER=wayland` needs to be set.
+* The functions that takes structs as first parameter are adapted in the binding to be a method to the struct.
+
+# Simple colored window
+
+Adapted from [SDL2 tutorial](https://jan.newmarch.name/Wayland/SDL/). It opens a window, color it light red and wait for 3 seconds before closing.
+
+```go
+package main
+
+import (
+	"log/slog"
+	"os"
+	"time"
+
+	"github.com/veandco/go-sdl2/sdl"
+)
+
+func main() {
+	slog.Info("Initializing...")
+	if err := sdl.Init(sdl.INIT_EVERYTHING); err != nil {
+		slog.Error("Failed to initialize SDL", "error", err)
+		os.Exit(1)
+	}
+
+	window, err := sdl.CreateWindow("Example", sdl.WINDOWPOS_UNDEFINED, sdl.WINDOWPOS_UNDEFINED, 1280, 720, sdl.WINDOWEVENT_SHOWN)
+	if err != nil {
+		slog.Error("Failed to create a window", "error", err)
+		os.Exit(1)
+	}
+
+	surface, err := window.GetSurface()
+	if err != nil {
+		slog.Error("Failed to get window surface", "error", err)
+		os.Exit(1)
+	}
+
+	c := sdl.MapRGB(surface.Format, 255, 90, 120)
+
+	if err := surface.FillRect(nil, c); err != nil {
+		slog.Error("Failed to fill rect", "error", err)
+		os.Exit(1)
+	}
+
+	if err := window.UpdateSurface(); err != nil {
+		slog.Error("Failed to update surface", "error", err)
+		os.Exit(1)
+	}
+
+	time.Sleep(time.Second * 3)
+
+	if err := window.Destroy(); err != nil {
+		slog.Error("failed to destroy window", "error", err)
+	}
+
+	sdl.Quit()
+}
+```
+
+It needs to run using the following command otherwise the window appears black:
+```sh
+SDL_VIDEODRIVER=wayland  go run main.go
+```
+
+The output looks like the following, Also notice the error while closing the window:
+```
+2025/01/26 12:40:32 INFO Initializing...
+2025/01/26 12:40:35 ERROR failed to destroy window error="That operation is not supported"
+```