We have a head

tinyrender1/image.go

@@ -36,6 +36,13 @@ func (fb *Framebuffer) Set(x uint, y uint, color uint) {
 	fb.Data[x+y*fb.Width] = color
 }
 
+func (fb *Framebuffer) SetSafe(x uint, y uint, color uint) {
+	if x >= fb.Width || y >= fb.Height {
+		return
+	}
+	fb.Data[x+y*fb.Width] = color
+}
+
 // Given some image data, return a string that is the ppm of it
 func (fb *Framebuffer) ExportPPM() string {
 	var result strings.Builder

tinyrender1/obj.go

@@ -64,16 +64,18 @@ func ParseObj(reader io.Reader) (*ObjModel, error) {
 			// Read a face; in our example, it's always three sets.
 			// For THIS example, we throw away those other values
 			var face Facef
-			for i := range 3 {
+			var vi [3]int
-				var vi, ti0, ti1 int
+			var ti int
-				_, err := fmt.Sscanf(line, "%d/%d/%d", &vi, &ti0, &ti1)
+			_, err := fmt.Sscanf(line, "%d/%d/%d %d/%d/%d %d/%d/%d",
+				&vi[0], &ti, &ti, &vi[1], &ti, &ti, &vi[2], &ti, &ti)
 			if err != nil {
 				return nil, err
 			}
-				if vi > len(result.Vertices) || vi < 1 {
+			for i := range 3 {
-					return nil, fmt.Errorf("Face vertex index out of bounds: %d", vi)
+				if vi[i] > len(result.Vertices) || vi[i] < 1 {
+					return nil, fmt.Errorf("Face vertex index out of bounds: %d", vi[i])
 				}
-				face[i] = result.Vertices[vi-1]
+				face[i] = result.Vertices[vi[i]-1]
 			}
 			result.Faces = append(result.Faces, face)
 		}

tinyrender1/render.go

@@ -173,7 +173,7 @@ func Bresenham2(fb *Framebuffer, color uint, x0 int, y0 int, x1 int, y1 int) {
 	err := dx + dy
 
 	for {
-		fb.Set(uint(x0), uint(y0), color)
+		fb.SetSafe(uint(x0), uint(y0), color)
 		if x0 == x1 && y0 == y1 {
 			break
 		}