progs/xdemos: added multictx.c (multi-context rendering demo)

Create one window and render into it with two GLX contexts.  Setup the
rendering state differently for each context to be sure there's no state
"bleeding" between contexts.

2 files changed, 586 insertions, 0 deletions

diff --git a/progs/xdemos/Makefile b/progs/xdemos/Makefile
index 6581df80398..53e1c54ef3c 100644
--- a/progs/xdemos/Makefile
+++ b/progs/xdemos/Makefile
@@ -26,6 +26,7 @@ PROGS = \
 	glxsnoop \
 	glxswapcontrol \
 	manywin \
+	multictx \
 	offset \
 	overlay \
 	pbinfo \
diff --git a/progs/xdemos/multictx.c b/progs/xdemos/multictx.c
new file mode 100644
index 00000000000..75255b28605
--- /dev/null
+++ b/progs/xdemos/multictx.c
@@ -0,0 +1,585 @@
+/*
+ * Copyright (C) 2009  VMware, Inc.   All Rights Reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/*
+ * Test rendering with two contexts into one window.
+ * Setup different rendering state for each context to check that
+ * context switching is handled properly.
+ *
+ * Brian Paul
+ * 6 Aug 2009
+ */
+
+
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <X11/Xlib.h>
+#include <X11/keysym.h>
+#include <GL/gl.h>
+#include <GL/glx.h>
+
+
+
+#ifndef M_PI
+#define M_PI 3.14159265
+#endif
+
+
+/** Event handler results: */
+#define NOP 0
+#define EXIT 1
+#define DRAW 2
+
+static GLfloat view_rotx = 0.0, view_roty = 210.0, view_rotz = 0.0;
+static GLint gear1, gear2;
+static GLfloat angle = 0.0;
+
+static GLboolean animate = GL_TRUE;	/* Animation */
+
+
+static double
+current_time(void)
+{
+   struct timeval tv;
+#ifdef __VMS
+   (void) gettimeofday(&tv, NULL );
+#else
+   struct timezone tz;
+   (void) gettimeofday(&tv, &tz);
+#endif
+   return (double) tv.tv_sec + tv.tv_usec / 1000000.0;
+}
+
+
+/*
+ *
+ *  Draw a gear wheel.  You'll probably want to call this function when
+ *  building a display list since we do a lot of trig here.
+ * 
+ *  Input:  inner_radius - radius of hole at center
+ *          outer_radius - radius at center of teeth
+ *          width - width of gear
+ *          teeth - number of teeth
+ *          tooth_depth - depth of tooth
+ */
+static void
+gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
+     GLint teeth, GLfloat tooth_depth)
+{
+   GLint i;
+   GLfloat r0, r1, r2;
+   GLfloat angle, da;
+   GLfloat u, v, len;
+
+   r0 = inner_radius;
+   r1 = outer_radius - tooth_depth / 2.0;
+   r2 = outer_radius + tooth_depth / 2.0;
+
+   da = 2.0 * M_PI / teeth / 4.0;
+
+   glShadeModel(GL_FLAT);
+
+   glNormal3f(0.0, 0.0, 1.0);
+
+   /* draw front face */
+   glBegin(GL_QUAD_STRIP);
+   for (i = 0; i <= teeth; i++) {
+      angle = i * 2.0 * M_PI / teeth;
+      glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
+      glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
+      if (i < teeth) {
+	 glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
+	 glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
+		    width * 0.5);
+      }
+   }
+   glEnd();
+
+   /* draw front sides of teeth */
+   glBegin(GL_QUADS);
+   da = 2.0 * M_PI / teeth / 4.0;
+   for (i = 0; i < teeth; i++) {
+      angle = i * 2.0 * M_PI / teeth;
+
+      glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
+      glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
+      glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
+		 width * 0.5);
+      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
+		 width * 0.5);
+   }
+   glEnd();
+
+   glNormal3f(0.0, 0.0, -1.0);
+
+   /* draw back face */
+   glBegin(GL_QUAD_STRIP);
+   for (i = 0; i <= teeth; i++) {
+      angle = i * 2.0 * M_PI / teeth;
+      glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
+      glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
+      if (i < teeth) {
+	 glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
+		    -width * 0.5);
+	 glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
+      }
+   }
+   glEnd();
+
+   /* draw back sides of teeth */
+   glBegin(GL_QUADS);
+   da = 2.0 * M_PI / teeth / 4.0;
+   for (i = 0; i < teeth; i++) {
+      angle = i * 2.0 * M_PI / teeth;
+
+      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
+		 -width * 0.5);
+      glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
+		 -width * 0.5);
+      glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
+      glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
+   }
+   glEnd();
+
+   /* draw outward faces of teeth */
+   glBegin(GL_QUAD_STRIP);
+   for (i = 0; i < teeth; i++) {
+      angle = i * 2.0 * M_PI / teeth;
+
+      glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
+      glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
+      u = r2 * cos(angle + da) - r1 * cos(angle);
+      v = r2 * sin(angle + da) - r1 * sin(angle);
+      len = sqrt(u * u + v * v);
+      u /= len;
+      v /= len;
+      glNormal3f(v, -u, 0.0);
+      glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
+      glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
+      glNormal3f(cos(angle), sin(angle), 0.0);
+      glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
+		 width * 0.5);
+      glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
+		 -width * 0.5);
+      u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da);
+      v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da);
+      glNormal3f(v, -u, 0.0);
+      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
+		 width * 0.5);
+      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
+		 -width * 0.5);
+      glNormal3f(cos(angle), sin(angle), 0.0);
+   }
+
+   glVertex3f(r1 * cos(0), r1 * sin(0), width * 0.5);
+   glVertex3f(r1 * cos(0), r1 * sin(0), -width * 0.5);
+
+   glEnd();
+
+   glShadeModel(GL_SMOOTH);
+
+   /* draw inside radius cylinder */
+   glBegin(GL_QUAD_STRIP);
+   for (i = 0; i <= teeth; i++) {
+      angle = i * 2.0 * M_PI / teeth;
+      glNormal3f(-cos(angle), -sin(angle), 0.0);
+      glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
+      glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
+   }
+   glEnd();
+}
+
+
+static void
+draw(int ctx)
+{
+   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+   glPushMatrix();
+   glRotatef(view_rotx, 1.0, 0.0, 0.0);
+   glRotatef(view_roty + angle, 0.0, 1.0, 0.0);
+   glRotatef(view_rotz, 0.0, 0.0, 1.0);
+
+   if (ctx == 0) {
+      glDisable(GL_CULL_FACE);
+      glPushMatrix();
+      glRotatef(angle, 0.0, 0.0, 1.0);
+      glCallList(gear1);
+      glPopMatrix();
+      /* This should not effect the other context's rendering */
+      glEnable(GL_CULL_FACE);
+      glCullFace(GL_FRONT_AND_BACK);
+   }
+   else {
+      glPushMatrix();
+      glRotatef(-2.0 * angle - 9.0, 0.0, 0.0, 1.0);
+      glCallList(gear2);
+      glPopMatrix();
+   }
+
+   glPopMatrix();
+
+   /* this flush is important since we'll be switching contexts next */
+   glFlush();
+}
+
+
+
+static void
+draw_frame(Display *dpy, Window win, GLXContext ctx1, GLXContext ctx2)
+{
+   static double tRot0 = -1.0;
+   double dt, t = current_time();
+
+   if (tRot0 < 0.0)
+      tRot0 = t;
+   dt = t - tRot0;
+   tRot0 = t;
+
+   if (animate) {
+      /* advance rotation for next frame */
+      angle += 70.0 * dt;  /* 70 degrees per second */
+      if (angle > 3600.0)
+         angle -= 3600.0;
+   }
+
+   glXMakeCurrent(dpy, (GLXDrawable) win, ctx1);
+   draw(0);
+
+   glXMakeCurrent(dpy, (GLXDrawable) win, ctx2);
+   draw(1);
+
+   glXSwapBuffers(dpy, win);
+}
+
+
+/* new window size or exposure */
+static void
+reshape(Display *dpy, Window win,
+        GLXContext ctx1, GLXContext ctx2, int width, int height)
+{
+   int i;
+
+   width /= 2;
+
+   /* loop: left half of window, right half of window */
+   for (i = 0; i < 2; i++) {
+      if (i == 0)
+         glXMakeCurrent(dpy, win, ctx1);
+      else
+         glXMakeCurrent(dpy, win, ctx2);
+
+      glViewport(width * i, 0, width, height);
+      glScissor(width * i, 0, width, height);
+
+      {
+         GLfloat h = (GLfloat) height / (GLfloat) width;
+
+         glMatrixMode(GL_PROJECTION);
+         glLoadIdentity();
+         glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0);
+      }
+
+      glMatrixMode(GL_MODELVIEW);
+      glLoadIdentity();
+      glTranslatef(0.0, 0.0, -30.0);
+   }
+}
+   
+
+
+static void
+init(Display *dpy, Window win, GLXContext ctx1, GLXContext ctx2)
+{
+   static GLfloat pos[4] = { 5.0, 5.0, 10.0, 0.0 };
+   static GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 };
+   static GLfloat green[4] = { 0.0, 0.8, 0.2, 0.5 };
+   /*static GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 };*/
+
+   /* first ctx */
+   {
+      static GLuint stipple[32] = {
+         0x00ff00ff, 0x00ff00ff, 0x00ff00ff, 0x00ff00ff,
+         0x00ff00ff, 0x00ff00ff, 0x00ff00ff, 0x00ff00ff,
+
+         0xff00ff00, 0xff00ff00, 0xff00ff00, 0xff00ff00,
+         0xff00ff00, 0xff00ff00, 0xff00ff00, 0xff00ff00,
+
+         0x00ff00ff, 0x00ff00ff, 0x00ff00ff, 0x00ff00ff,
+         0x00ff00ff, 0x00ff00ff, 0x00ff00ff, 0x00ff00ff,
+
+         0xff00ff00, 0xff00ff00, 0xff00ff00, 0xff00ff00,
+         0xff00ff00, 0xff00ff00, 0xff00ff00, 0xff00ff00
+      };
+
+      glXMakeCurrent(dpy, win, ctx1);
+
+      glLightfv(GL_LIGHT0, GL_POSITION, pos);
+      glEnable(GL_LIGHTING);
+      glEnable(GL_LIGHT0);
+      glEnable(GL_DEPTH_TEST);
+
+      gear1 = glGenLists(1);
+      glNewList(gear1, GL_COMPILE);
+      glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red);
+      gear(1.0, 4.0, 1.0, 20, 0.7);
+      glEndList();
+
+      glEnable(GL_NORMALIZE);
+      glEnable(GL_SCISSOR_TEST);
+      glClearColor(0.4, 0.4, 0.4, 1.0);
+
+      glPolygonStipple((GLubyte *) stipple);
+      glEnable(GL_POLYGON_STIPPLE);
+   }
+
+   /* second ctx */
+   {
+      glXMakeCurrent(dpy, win, ctx2);
+
+      glLightfv(GL_LIGHT0, GL_POSITION, pos);
+      glEnable(GL_LIGHTING);
+      glEnable(GL_LIGHT0);
+      glEnable(GL_DEPTH_TEST);
+
+      gear2 = glGenLists(1);
+      glNewList(gear2, GL_COMPILE);
+      glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green);
+      gear(1.5, 3.0, 1.5, 16, 0.7);
+      glEndList();
+
+      glEnable(GL_NORMALIZE);
+      glEnable(GL_SCISSOR_TEST);
+      glClearColor(0.6, 0.6, 0.6, 1.0);
+
+      glEnable(GL_BLEND);
+      glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+   }
+}
+
+
+/**
+ * Create an RGB, double-buffered window.
+ * Return the window and two context handles.
+ */
+static void
+make_window_and_contexts( Display *dpy, const char *name,
+                          int x, int y, int width, int height,
+                          Window *winRet,
+                          GLXContext *ctxRet1,
+                          GLXContext *ctxRet2)
+{
+   int attribs[] = { GLX_RGBA,
+                     GLX_RED_SIZE, 1,
+                     GLX_GREEN_SIZE, 1,
+                     GLX_BLUE_SIZE, 1,
+                     GLX_DOUBLEBUFFER,
+                     GLX_DEPTH_SIZE, 1,
+                     None };
+   int scrnum;
+   XSetWindowAttributes attr;
+   unsigned long mask;
+   Window root;
+   Window win;
+   XVisualInfo *visinfo;
+
+   scrnum = DefaultScreen( dpy );
+   root = RootWindow( dpy, scrnum );
+
+   visinfo = glXChooseVisual( dpy, scrnum, attribs );
+   if (!visinfo) {
+      printf("Error: couldn't get an RGB, Double-buffered visual\n");
+      exit(1);
+   }
+
+   /* 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, root, x, y, width, height,
+		        0, visinfo->depth, InputOutput,
+		        visinfo->visual, mask, &attr );
+
+   /* set hints and properties */
+   {
+      XSizeHints sizehints;
+      sizehints.x = x;
+      sizehints.y = y;
+      sizehints.width  = width;
+      sizehints.height = height;
+      sizehints.flags = USSize | USPosition;
+      XSetNormalHints(dpy, win, &sizehints);
+      XSetStandardProperties(dpy, win, name, name,
+                              None, (char **)NULL, 0, &sizehints);
+   }
+
+   *winRet = win;
+   *ctxRet1 = glXCreateContext( dpy, visinfo, NULL, True );
+   *ctxRet2 = glXCreateContext( dpy, visinfo, NULL, True );
+
+   if (!*ctxRet1 || !*ctxRet2) {
+      printf("Error: glXCreateContext failed\n");
+      exit(1);
+   }
+
+   XFree(visinfo);
+}
+
+
+/**
+ * Handle one X event.
+ * \return NOP, EXIT or DRAW
+ */
+static int
+handle_event(Display *dpy, Window win, GLXContext ctx1, GLXContext ctx2,
+             XEvent *event)
+{
+   (void) dpy;
+   (void) win;
+
+   switch (event->type) {
+   case Expose:
+      return DRAW;
+   case ConfigureNotify:
+      reshape(dpy, win, ctx1, ctx2,
+              event->xconfigure.width, event->xconfigure.height);
+      break;
+   case KeyPress:
+      {
+         char buffer[10];
+         int r, code;
+         code = XLookupKeysym(&event->xkey, 0);
+         if (code == XK_Left) {
+            view_roty += 5.0;
+         }
+         else if (code == XK_Right) {
+            view_roty -= 5.0;
+         }
+         else if (code == XK_Up) {
+            view_rotx += 5.0;
+         }
+         else if (code == XK_Down) {
+            view_rotx -= 5.0;
+         }
+         else {
+            r = XLookupString(&event->xkey, buffer, sizeof(buffer),
+                              NULL, NULL);
+            if (buffer[0] == 27) {
+               /* escape */
+               return EXIT;
+            }
+            else if (buffer[0] == 'a' || buffer[0] == 'A') {
+               animate = !animate;
+            }
+         }
+         return DRAW;
+      }
+   }
+   return NOP;
+}
+
+
+static void
+event_loop(Display *dpy, Window win, GLXContext ctx1, GLXContext ctx2)
+{
+   while (1) {
+      int op;
+      while (!animate || XPending(dpy) > 0) {
+         XEvent event;
+         XNextEvent(dpy, &event);
+         op = handle_event(dpy, win, ctx1, ctx2, &event);
+         if (op == EXIT)
+            return;
+         else if (op == DRAW)
+            break;
+      }
+
+      draw_frame(dpy, win, ctx1, ctx2);
+   }
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   unsigned int winWidth = 800, winHeight = 400;
+   int x = 0, y = 0;
+   Display *dpy;
+   Window win;
+   GLXContext ctx1, ctx2;
+   char *dpyName = NULL;
+   GLboolean printInfo = GL_FALSE;
+   int i;
+
+   for (i = 1; i < argc; i++) {
+      if (strcmp(argv[i], "-display") == 0) {
+         dpyName = argv[i+1];
+         i++;
+      }
+      else {
+         return 1;
+      }
+   }
+
+   dpy = XOpenDisplay(dpyName);
+   if (!dpy) {
+      printf("Error: couldn't open display %s\n",
+	     dpyName ? dpyName : getenv("DISPLAY"));
+      return -1;
+   }
+
+   make_window_and_contexts(dpy, "multictx", x, y, winWidth, winHeight,
+                            &win, &ctx1, &ctx2);
+   XMapWindow(dpy, win);
+
+   if (printInfo) {
+      printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
+      printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
+      printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
+      printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
+   }
+
+   init(dpy, win, ctx1, ctx2);
+
+   /* Set initial projection/viewing transformation.
+    * We can't be sure we'll get a ConfigureNotify event when the window
+    * first appears.
+    */
+   reshape(dpy, win, ctx1, ctx2, winWidth, winHeight);
+
+   event_loop(dpy, win, ctx1, ctx2);
+
+   glDeleteLists(gear1, 1);
+   glDeleteLists(gear2, 1);
+   glXDestroyContext(dpy, ctx1);
+   glXDestroyContext(dpy, ctx2);
+   XDestroyWindow(dpy, win);
+   XCloseDisplay(dpy);
+
+   return 0;
+}