From d4b2829de83ca5f0efd3d1ee2683ee400e63ffe2 Mon Sep 17 00:00:00 2001
From: David Robillard <d@drobilla.net>
Date: Sun, 29 Apr 2012 06:08:19 +0000
Subject: Scroll API.

---
 pugl/pugl.h          |  7 +++++++
 pugl/pugl_internal.h |  7 +++++++
 pugl/pugl_x11.c      | 17 ++++++++++++++++-
 pugl_test.c          | 14 ++++++++++++--
 4 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/pugl/pugl.h b/pugl/pugl.h
index a764620..f173525 100644
--- a/pugl/pugl.h
+++ b/pugl/pugl.h
@@ -55,6 +55,7 @@ typedef void (*PuglMouseFunc)(PuglWindow* handle,
                               int button, bool down,
                               int x, int y);
 typedef void (*PuglReshapeFunc)(PuglWindow* handle, int width, int height);
+typedef void (*PuglScrollFunc)(PuglWindow* handle, int dx, int dy);
 
 /**
    Create a new GL window.
@@ -119,6 +120,12 @@ puglSetMotionFunc(PuglWindow* window, PuglMotionFunc motionFunc);
 void
 puglSetMouseFunc(PuglWindow* window, PuglMouseFunc mouseFunc);
 
+/**
+   Set the function to call on scroll events.
+*/
+void
+puglSetScrollFunc(PuglWindow* window, PuglScrollFunc scrollFunc);
+
 /**
    Set the function to call when the window size changes.
 */
diff --git a/pugl/pugl_internal.h b/pugl/pugl_internal.h
index 8a7b217..3685522 100644
--- a/pugl/pugl_internal.h
+++ b/pugl/pugl_internal.h
@@ -35,6 +35,7 @@ struct PuglWindowImpl {
 	PuglMotionFunc   motionFunc;
 	PuglMouseFunc    mouseFunc;
 	PuglReshapeFunc  reshapeFunc;
+	PuglScrollFunc   scrollFunc;
 
 	PuglPlatformData* impl;
 
@@ -90,3 +91,9 @@ puglSetReshapeFunc(PuglWindow* window, PuglReshapeFunc reshapeFunc)
 {
 	window->reshapeFunc = reshapeFunc;
 }
+
+void
+puglSetScrollFunc(PuglWindow* window, PuglScrollFunc scrollFunc)
+{
+	window->scrollFunc = scrollFunc;
+}
diff --git a/pugl/pugl_x11.c b/pugl/pugl_x11.c
index d8685b2..735cdb1 100644
--- a/pugl/pugl_x11.c
+++ b/pugl/pugl_x11.c
@@ -238,8 +238,23 @@ puglProcessEvents(PuglWindow* win)
 			}
 			break;
 		case ButtonPress:
+			if (event.xbutton.button >= 4 && event.xbutton.button <= 7) {
+				if (win->scrollFunc) {
+					int dx = 0, dy = 0;
+					switch (event.xbutton.button) {
+					case 4: dy =  1; break;
+					case 5: dy = -1; break;
+					case 6: dx = -1; break;
+					case 7: dx =  1; break;
+					}
+					win->scrollFunc(win, dx, dy);
+				}
+				break;
+			}
+			// nobreak
 		case ButtonRelease:
-			if (win->mouseFunc) {
+			if (win->mouseFunc &&
+			    (event.xbutton.button < 4 || event.xbutton.button > 7)) {
 				win->mouseFunc(win,
 				               event.xbutton.button, event.type == ButtonPress,
 				               event.xbutton.x, event.xbutton.y);
diff --git a/pugl_test.c b/pugl_test.c
index 03afac0..57b9e5e 100644
--- a/pugl_test.c
+++ b/pugl_test.c
@@ -34,6 +34,7 @@
 static int   quit   = 0;
 static float xAngle = 0.0f;
 static float yAngle = 0.0f;
+static float dist   = 10.0f;
 
 #define KEY_ESCAPE 27
 
@@ -43,7 +44,7 @@ onDisplay(PuglWindow* win)
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 	glLoadIdentity();
 
-	glTranslatef(0.0f, 0.0f, -10.0f);
+	glTranslatef(0.0f, 0.0f, dist * -1);
 	glRotatef(xAngle, 0.0f, 1.0f, 0.0f);
 	glRotatef(yAngle, 1.0f, 0.0f, 0.0f);
 
@@ -102,12 +103,20 @@ onMotion(PuglWindow* win, int x, int y)
 }
 
 static void
-onMouse(PuglWindow* handle, int button, bool press, int x, int y)
+onMouse(PuglWindow* win, int button, bool press, int x, int y)
 {
 	fprintf(stderr, "Mouse %d %s at %d,%d\n",
 	        button, press ? "down" : "up", x, y);
 }
 
+static void
+onScroll(PuglWindow* win, int dx, int dy)
+{
+	fprintf(stderr, "Scroll %d %d\n", dx, dy);
+	dist += dy / 4.0f;
+	puglPostRedisplay(win);
+}
+
 static void
 onClose(PuglWindow* win)
 {
@@ -122,6 +131,7 @@ main(int argc, char** argv)
 	puglSetKeyboardFunc(win, onKeyboard);
 	puglSetMotionFunc(win, onMotion);
 	puglSetMouseFunc(win, onMouse);
+	puglSetScrollFunc(win, onScroll);
 	puglSetDisplayFunc(win, onDisplay);
 	puglSetCloseFunc(win, onClose);
 
-- 
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