started adding tests

canvas_test.go

@@ -0,0 +1,106 @@
+package canvas_test
+
+import (
+	"fmt"
+	"image/png"
+	"os"
+	"runtime"
+	"strings"
+	"testing"
+
+	"github.com/tfriedel6/canvas"
+	"github.com/tfriedel6/canvas/sdlcanvas"
+)
+
+func run(t *testing.T, fn func(cv *canvas.Canvas)) {
+	wnd, cv, err := sdlcanvas.CreateWindow(100, 100, "test")
+	if err != nil {
+		t.Fatalf("Failed to crete window: %v", err)
+		return
+	}
+	defer wnd.Destroy()
+
+	wnd.StartFrame()
+	cv.ClearRect(0, 0, 100, 100)
+	fn(cv)
+	img := cv.GetImageData(0, 0, 100, 100)
+
+	caller, _, _, ok := runtime.Caller(1)
+	if !ok {
+		t.Fatal("Failed to get caller")
+	}
+
+	callerFunc := runtime.FuncForPC(caller)
+	if callerFunc == nil {
+		t.Fatal("Failed to get caller function")
+	}
+
+	const prefix = "canvas_test.Test"
+	callerFuncName := callerFunc.Name()
+	callerFuncName = callerFuncName[strings.Index(callerFuncName, prefix)+len(prefix):]
+
+	fileName := fmt.Sprintf("testimages/%s.png", callerFuncName)
+
+	_, err = os.Stat(fileName)
+	if err != nil && !os.IsNotExist(err) {
+		t.Fatalf("Failed to stat file \"%s\": %v", fileName, err)
+	}
+
+	if os.IsNotExist(err) {
+		f, err := os.OpenFile(fileName, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0777)
+		if err != nil {
+			t.Fatalf("Failed to create file \"%s\"", fileName)
+		}
+		defer f.Close()
+
+		err = png.Encode(f, img)
+		if err != nil {
+			t.Fatalf("Failed to encode PNG")
+		}
+		return
+	}
+
+	f, err := os.Open(fileName)
+	if err != nil {
+		t.Fatalf("Failed to open file \"%s\": %v", fileName, err)
+	}
+	defer f.Close()
+
+	refImg, err := png.Decode(f)
+	if err != nil {
+		t.Fatalf("Failed to decode file \"%s\": %v", fileName, err)
+	}
+
+	if b := img.Bounds(); b.Min.X != 0 || b.Min.Y != 0 || b.Max.X != 100 || b.Max.Y != 100 {
+		t.Fatalf("Image bounds must be 0,0,100,100")
+	}
+	if b := refImg.Bounds(); b.Min.X != 0 || b.Min.Y != 0 || b.Max.X != 100 || b.Max.Y != 100 {
+		t.Fatalf("Image bounds must be 0,0,100,100")
+	}
+
+	for y := 0; y < 100; y++ {
+		for x := 0; x < 100; x++ {
+			r1, g1, b1, a1 := img.At(x, y).RGBA()
+			r2, g2, b2, a2 := refImg.At(x, y).RGBA()
+			if r1 != r2 || g1 != g2 || b1 != b2 || a1 != a2 {
+				t.FailNow()
+			}
+		}
+	}
+}
+
+func TestFillRect(t *testing.T) {
+	run(t, func(cv *canvas.Canvas) {
+		cv.SetFillStyle("#F00")
+		cv.FillRect(10, 10, 10, 10)
+
+		cv.SetFillStyle("#F008")
+		cv.FillRect(30, 10, 10, 10)
+
+		cv.SetFillStyle(64, 96, 128, 160)
+		cv.FillRect(50, 10, 10, 10)
+
+		cv.SetFillStyle(0.5, 0.7, 0.2, 0.8)
+		cv.FillRect(70, 10, 10, 10)
+	})
+}