overlay planes test

progs/xdemos/Makefile

@@ -20,6 +20,7 @@ PROGS = glthreads \
 	glxswapcontrol \
 	manywin \
 	offset \
+	overlay \
 	pbinfo \
 	pbdemo \
 	wincopy \

progs/xdemos/overlay.c

@@ -0,0 +1,245 @@
+/*
+ * GLX overlay test/demo.
+ *
+ * Brian Paul
+ * 18 July 2005
+ */
+
+#include <GL/gl.h>
+#include <GL/glx.h>
+#include <X11/keysym.h>
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static int WinWidth = 300, WinHeight = 300;
+static Window NormalWindow = 0;
+static Window OverlayWindow = 0;
+static GLXContext NormalContext = 0;
+static GLXContext OverlayContext = 0;
+static GLboolean RGBOverlay = GL_FALSE;
+static GLfloat Angle = 0.0;
+
+
+static void
+RedrawNormal(Display *dpy)
+{
+   glXMakeCurrent(dpy, NormalWindow, NormalContext);
+   glViewport(0, 0, WinWidth, WinHeight);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
+   glMatrixMode(GL_MODELVIEW);
+   glClearColor(0.5, 0.5, 0.5, 1.0);
+   glClear(GL_COLOR_BUFFER_BIT);
+   glColor3f(1.0, 1.0, 0.0);
+   glPushMatrix();
+   glRotatef(Angle, 0, 0, 1);
+   glRectf(-0.8, -0.8, 0.8, 0.8);
+   glPopMatrix();
+   glXSwapBuffers(dpy, NormalWindow);
+}
+
+
+static void
+RedrawOverlay(Display *dpy)
+{
+   glXMakeCurrent(dpy, OverlayWindow, OverlayContext);
+   glViewport(0, 0, WinWidth, WinHeight);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
+   glMatrixMode(GL_MODELVIEW);
+   glClear(GL_COLOR_BUFFER_BIT);
+   if (RGBOverlay) {
+      glColor3f(0.0, 1.0, 1.0);
+   }
+   else {
+      glIndexi(2);
+   }
+   glBegin(GL_LINES);
+   glVertex2f(-1, -1);
+   glVertex2f(1, 1);
+   glVertex2f(1, -1);
+   glVertex2f(-1, 1);
+   glEnd();
+   glXSwapBuffers(dpy, OverlayWindow);
+}
+
+
+static Window
+MakeWindow(Display *dpy, XVisualInfo *visinfo, Window parent,
+             unsigned int width, unsigned int height)
+{
+   int scrnum;
+   XSetWindowAttributes attr;
+   unsigned long mask;
+   Window root;
+   Window win;
+
+   scrnum = DefaultScreen(dpy);
+   root = RootWindow(dpy, scrnum);
+
+   /* window attributes */
+   attr.background_pixel = 0;
+   attr.border_pixel = 0;
+   attr.colormap = XCreateColormap(dpy, root, visinfo->visual, AllocNone);
+   attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
+   mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
+
+   win = XCreateWindow(dpy, parent, 0, 0, width, height,
+		        0, visinfo->depth, InputOutput,
+		        visinfo->visual, mask, &attr);
+   return win;
+}
+
+
+static void
+MakeNormalWindow(Display *dpy)
+{
+   int attrib[] = { GLX_RGBA,
+		    GLX_RED_SIZE, 1,
+		    GLX_GREEN_SIZE, 1,
+		    GLX_BLUE_SIZE, 1,
+		    GLX_DOUBLEBUFFER,
+		    None };
+   int scrnum;
+   Window root;
+   XVisualInfo *visinfo;
+
+   scrnum = DefaultScreen(dpy);
+   root = RootWindow(dpy, scrnum);
+
+   visinfo = glXChooseVisual(dpy, scrnum, attrib);
+   if (!visinfo) {
+      printf("Error: couldn't get an RGB, Double-buffered visual\n");
+      exit(1);
+   }
+
+   NormalWindow = MakeWindow(dpy, visinfo, root, WinWidth, WinHeight);
+   assert(NormalWindow);
+
+   NormalContext = glXCreateContext(dpy, visinfo, NULL, True);
+   assert(NormalContext);
+}
+
+
+static void
+MakeOverlayWindow(Display *dpy)
+{
+   int rgbAttribs[] = {
+      GLX_RGBA,
+      GLX_RED_SIZE, 1,
+      GLX_GREEN_SIZE, 1,
+      GLX_BLUE_SIZE, 1,
+      GLX_DOUBLEBUFFER,
+      GLX_LEVEL, 1,
+      None
+   };
+   int indexAttribs[] = {
+      /*GLX_RGBA, leave this out */
+      GLX_RED_SIZE, 1,
+      GLX_GREEN_SIZE, 1,
+      GLX_BLUE_SIZE, 1,
+      GLX_DOUBLEBUFFER,
+      GLX_LEVEL, 1,
+      None
+   };
+   int scrnum;
+   Window root;
+   XVisualInfo *visinfo;
+
+   scrnum = DefaultScreen(dpy);
+   root = RootWindow(dpy, scrnum);
+
+   visinfo = glXChooseVisual(dpy, scrnum, rgbAttribs);
+   if (visinfo) {
+      printf("Found RGB overlay visual 0x%x\n", (int) visinfo->visualid);
+      RGBOverlay = GL_TRUE;
+   }
+   else {
+      visinfo = glXChooseVisual(dpy, scrnum, indexAttribs);
+      if (visinfo) {
+         printf("Found Color Index overlay visual 0x%x\n",
+                (int) visinfo->visualid);
+         /* XXX setup the colormap entries! */
+      }
+      else {
+         printf("Error: couldn't get an overlay visual!\n");
+         exit(1);
+      }
+   }
+
+   OverlayWindow = MakeWindow(dpy, visinfo, NormalWindow, WinWidth, WinHeight);
+   assert(OverlayWindow);
+
+   OverlayContext = glXCreateContext(dpy, visinfo, NULL, True);
+   assert(OverlayContext);
+}
+
+
+static void
+EventLoop(Display *dpy)
+{
+   XEvent event;
+
+   while (1) {
+      XNextEvent(dpy, &event);
+
+      switch (event.type) {
+	 case Expose:
+	    RedrawNormal(dpy);
+	    RedrawOverlay(dpy);
+	    break;
+	 case ConfigureNotify:
+            WinWidth = event.xconfigure.width;
+            WinHeight = event.xconfigure.height;
+            if (event.xconfigure.window == NormalWindow)
+               XResizeWindow(dpy, OverlayWindow, WinWidth, WinHeight);
+	    break;
+         case KeyPress:
+            {
+               char buffer[10];
+               int r, code;
+               code = XLookupKeysym(&event.xkey, 0);
+	       r = XLookupString(&event.xkey, buffer, sizeof(buffer),
+				 NULL, NULL);
+	       if (buffer[0] == 27) {
+                  /* escape */
+                  return;
+               }
+               else if (buffer[0] == ' ') {
+                  Angle += 5.0;
+                  RedrawNormal(dpy);
+               }
+            }
+            break;
+         default:
+            ; /* nothing */
+      }
+   }
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   Display *dpy = XOpenDisplay(NULL);
+
+   assert(dpy);
+
+   MakeNormalWindow(dpy);
+   MakeOverlayWindow(dpy);
+
+   XMapWindow(dpy, NormalWindow);
+   XMapWindow(dpy, OverlayWindow);
+
+   EventLoop(dpy);
+
+   glXDestroyContext(dpy, OverlayContext);
+   glXDestroyContext(dpy, NormalContext);
+   XDestroyWindow(dpy, OverlayWindow);
+   XDestroyWindow(dpy, NormalWindow);
+
+   return 0;
+}