examples: rewrite text example as drawing-text

Signed-off-by: Lilis Iskandar <lilis@veand.co>

examples/drawing-text/drawing-text.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"os"
+
+	"github.com/veandco/go-sdl2/sdl"
+	"github.com/veandco/go-sdl2/ttf"
+)
+
+const (
+	fontPath = "../../assets/test.ttf"
+	fontSize = 32
+)
+
+func run() (err error) {
+	var window *sdl.Window
+	var font *ttf.Font
+	var surface *sdl.Surface
+	var text *sdl.Surface
+
+	if err = ttf.Init(); err != nil {
+		return
+	}
+	defer ttf.Quit()
+
+	if err = sdl.Init(sdl.INIT_VIDEO); err != nil {
+		return
+	}
+	defer sdl.Quit()
+
+	// Create a window for us to draw the text on
+	if window, err = sdl.CreateWindow("Drawing text", sdl.WINDOWPOS_UNDEFINED, sdl.WINDOWPOS_UNDEFINED, 800, 600, sdl.WINDOW_SHOWN); err != nil {
+		return
+	}
+	defer window.Destroy()
+
+	if surface, err = window.GetSurface(); err != nil {
+		return
+	}
+
+	// Load the font for our text
+	if font, err = ttf.OpenFont(fontPath, fontSize); err != nil {
+		return
+	}
+	defer font.Close()
+
+	// Create a red text with the font
+	if text, err = font.RenderUTF8Blended("Hello, World!", sdl.Color{R: 255, G: 0, B: 0, A: 255}); err != nil {
+		return
+	}
+	defer text.Free()
+
+	// Draw the text around the center of the window
+	if err = text.Blit(nil, surface, &sdl.Rect{X: 400 - (text.W / 2), Y: 300 - (text.H / 2), W: 0, H: 0}); err != nil {
+		return
+	}
+
+	// Update the window surface with what we have drawn
+	window.UpdateSurface()
+
+	// Run infinite loop until user closes the window
+	running := true
+	for running {
+		for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
+			switch event.(type) {
+			case *sdl.QuitEvent:
+				running = false
+			}
+		}
+
+		sdl.Delay(16)
+	}
+
+	return
+}
+
+func main() {
+	if err := run(); err != nil {
+		os.Exit(1)
+	}
+}

examples/text/text.go

@@ -1,66 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"os"
-
-	"github.com/veandco/go-sdl2/sdl"
-	"github.com/veandco/go-sdl2/ttf"
-)
-
-var winTitle string = "Text"
-var winWidth, winHeight int32 = 800, 600
-
-func run() int {
-	var window *sdl.Window
-	var font *ttf.Font
-	var surface *sdl.Surface
-	var solid *sdl.Surface
-	var err error
-
-	sdl.Init(sdl.INIT_VIDEO)
-
-	if err := ttf.Init(); err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to initialize TTF: %s\n", err)
-		return 1
-	}
-
-	if window, err = sdl.CreateWindow(winTitle, sdl.WINDOWPOS_UNDEFINED, sdl.WINDOWPOS_UNDEFINED, winWidth, winHeight, sdl.WINDOW_SHOWN); err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to create window: %s\n", err)
-		return 2
-	}
-	defer window.Destroy()
-
-	if font, err = ttf.OpenFont("../../assets/test.ttf", 32); err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to open font: %s\n", err)
-		return 4
-	}
-	defer font.Close()
-
-	if solid, err = font.RenderUTF8Solid("Hello, World!", sdl.Color{255, 0, 0, 255}); err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to render text: %s\n", err)
-		return 5
-	}
-	defer solid.Free()
-
-	if surface, err = window.GetSurface(); err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to get window surface: %s\n", err)
-		return 6
-	}
-
-	if err = solid.Blit(nil, surface, nil); err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to put text on window surface: %s\n", err)
-		return 7
-	}
-
-	// Show the pixels for a while
-	window.UpdateSurface()
-	sdl.PollEvent()
-	sdl.Delay(3000)
-
-	return 0
-}
-
-func main() {
-	os.Exit(run())
-}