Render sprites from sprite sheets (no animation yet)

utils_texture.go

@@ -10,6 +10,8 @@ var TexList map[string]*sdl.Texture
 
 func drawTexture(
 	tex *sdl.Texture,
+	size VectorInt32,
+	sheetposition VectorInt32,
 	position Vector,
 	rotation float64,
 	renderer *sdl.Renderer) error {
@@ -19,16 +21,24 @@ func drawTexture(
 		return fmt.Errorf("querying texture: %v", err)
 	}
 
+	// If we're given -1,-1 for the size then we're using the entire texture
+	if size.X < 0 {
+		size.X = width
+	}
+	if size.Y < 0 {
+		size.Y = height
+	}
+
 	// Convert coordinates to the top left of the sprite
-	position.X -= float64(width) / 2.0
-	position.Y -= float64(height) / 2.0
+	position.X -= float64(size.X) / 2.0
+	position.Y -= float64(size.Y) / 2.0
 
 	return renderer.CopyEx(
 		tex,
-		&sdl.Rect{X: 0, Y: 0, W: width, H: height},
-		&sdl.Rect{X: int32(position.X), Y: int32(position.Y), W: width, H: height},
+		&sdl.Rect{X: sheetposition.X, Y: sheetposition.Y, W: size.X, H: size.Y},
+		&sdl.Rect{X: int32(position.X), Y: int32(position.Y), W: size.X, H: size.Y},
 		rotation,
-		&sdl.Point{X: width / 2, Y: height / 2},
+		&sdl.Point{X: size.X / 2, Y: size.Y / 2},
 		sdl.FLIP_NONE)
 }