feat: add writePixels() utility to astrotiff module in @observerly/iris

pkg/astrotiff/writer.go

@@ -0,0 +1,38 @@
+/*****************************************************************************************************************/
+
+//	@author		Michael Roberts <[email protected]>
+//	@package	@observerly/iris/astrotiff
+//	@license	Copyright © 2021-2024 observerly
+
+/*****************************************************************************************************************/
+
+package astrotiff
+
+/*****************************************************************************************************************/
+
+import (
+	"io"
+)
+
+/*****************************************************************************************************************/
+
+// writePixels writes the internal byte array of an image to w. It is less general
+// but much faster then encode. writePixels is used when pix directly
+// corresponds to one of the TIFF image types.
+func writePixels(w io.Writer, pix []byte, nrows, length, stride int) error {
+	if length == stride {
+		_, err := w.Write(pix[:nrows*length])
+		return err
+	}
+
+	for ; nrows > 0; nrows-- {
+		if _, err := w.Write(pix[:length]); err != nil {
+			return err
+		}
+		pix = pix[stride:]
+	}
+
+	return nil
+}
+
+/*****************************************************************************************************************/