4 files changed, 9 insertions, 10 deletions
diff --git a/engines/glk/window_text_buffer.cpp b/engines/glk/window_text_buffer.cpp
index ce4dd7c22e..0faafc803c 100644
--- a/engines/glk/window_text_buffer.cpp
+++ b/engines/glk/window_text_buffer.cpp
@@ -1587,8 +1587,7 @@ void TextBufferWindow::scrollResize() {
 	_scrollBack += SCROLLBACK;
 }
 
-int TextBufferWindow::calcWidth(uint32 *chars, Attributes *attrs, int startchar,
-								int numChars, int spw) {
+int TextBufferWindow::calcWidth(const uint32 *chars, const Attributes *attrs, int startchar, int numChars, int spw) {
 	Screen &screen = *g_vm->_screen;
 	int w = 0;
 	int a, b;
diff --git a/engines/glk/window_text_buffer.h b/engines/glk/window_text_buffer.h
index 47d87a45ab..0ac74d2e2a 100644
--- a/engines/glk/window_text_buffer.h
+++ b/engines/glk/window_text_buffer.h
@@ -91,7 +91,7 @@ private:
 
 	void scrollOneLine(bool forced);
 	void scrollResize();
-	int calcWidth(uint32 *chars, Attributes *attrs, int startchar, int numchars, int spw);
+	int calcWidth(const uint32 *chars, const Attributes *attrs, int startchar, int numchars, int spw);
 public:
 	int _width, _height;
 	int _spaced;
diff --git a/engines/glk/windows.cpp b/engines/glk/windows.cpp
index c8ab44768d..624defa9f5 100644
--- a/engines/glk/windows.cpp
+++ b/engines/glk/windows.cpp
@@ -730,7 +730,7 @@ void Attributes::clear() {
 	style = 0;
 }
 
-byte *Attributes::attrBg(WindowStyle *styles) {
+const byte *Attributes::attrBg(const WindowStyle *styles) {
 	int revset = reverse || (styles[style].reverse && !Windows::_overrideReverse);
 
 	int zfset = fgset ? fgset : Windows::_overrideFgSet;
@@ -771,7 +771,7 @@ byte *Attributes::attrBg(WindowStyle *styles) {
 	}
 }
 
-byte *Attributes::attrFg(WindowStyle *styles) {
+const byte *Attributes::attrFg(const WindowStyle *styles) {
 	int revset = reverse || (styles[style].reverse && !Windows::_overrideReverse);
 
 	int zfset = fgset ? fgset : Windows::_overrideFgSet;
diff --git a/engines/glk/windows.h b/engines/glk/windows.h
index c905556f9e..c917d2f04b 100644
--- a/engines/glk/windows.h
+++ b/engines/glk/windows.h
@@ -328,7 +328,7 @@ struct Attributes {
 	/**
 	 * Equality comparison
 	 */
-	bool operator==(const Attributes &src) {
+	bool operator==(const Attributes &src) const {
 		return fgset == src.fgset && bgset == src.bgset && reverse == src.reverse
 			   && style == src.style && fgcolor == src.fgcolor && bgcolor == src.bgcolor
 			   && hyper == src.hyper;
@@ -336,7 +336,7 @@ struct Attributes {
 	/**
 	 * Inequality comparison
 	 */
-	bool operator!=(const Attributes &src) {
+	bool operator!=(const Attributes &src) const {
 		return fgset != src.fgset || bgset != src.bgset || reverse != src.reverse
 			   || style != src.style || fgcolor != src.fgcolor || bgcolor != src.bgcolor
 			   || hyper != src.hyper;
@@ -345,17 +345,17 @@ struct Attributes {
 	/**
 	 * Return the background color for the current font style
 	 */
-	byte *attrBg(WindowStyle *styles);
+	const byte *attrBg(const WindowStyle *styles);
 
 	/**
 	 * Return the foreground color for the current font style
 	 */
-	byte *attrFg(WindowStyle *styles);
+	const byte *attrFg(const WindowStyle *styles);
 
 	/**
 	 * Get the font for the current font style
 	 */
-	FACES attrFont(WindowStyle *styles) const {
+	FACES attrFont(const WindowStyle *styles) const {
 		return styles[style].font;
 	}
 };