--- a/glxdragon.cpp	Mon Oct 28 12:59:18 2019 +0200
+++ b/glxdragon.cpp	Mon Oct 28 13:08:26 2019 +0200
@@ -39,15 +39,15 @@
 #include <vector>
 #include <cstdio>
 
-
-#define SET_FRAMES (180 * 2)
+/* Default settings etc. constants
+ */
+#define SET_DEF_WIDTH   1280
+#define SET_DEF_HEIGHT  960
+#define SET_FRAMES      (180 * 2)
 
 
-bool optUseShaders = false;
-SDL_Window *dmWindow = NULL;
-SDL_GLContext dmGLContext = NULL;
-
-
+/* Structures
+ */
 struct Mesh
 {
     int nvertices, nfaces;
@@ -59,6 +59,19 @@
 
 
 
+/* Options
+ */
+bool   optUseShaders = false;
+int    optWidth = SET_DEF_WIDTH,
+       optHeight = SET_DEF_HEIGHT;
+
+
+/* Globals
+ */
+SDL_Window *dmWindow = NULL;
+SDL_GLContext dmGLContext = NULL;
+
+
 bool dmInitSDLGL(const int width, const int height, const char *title)
 {
     // Set GL attributes
@@ -296,25 +309,47 @@
     int startTime, nframes = 0;
 
     // Check commandline argument for enabling shaders
-
     for (int narg = 1; narg < argc; narg++)
     {
         char *arg = argv[narg];
-        if (strstr(arg, "help") != NULL ||
-            strstr(arg, "?") != NULL)
-            optShowHelp = true;
-        else
-        if (strstr(arg, "glsl") != NULL ||
-            strstr(arg, "sha") != NULL)
-            optUseShaders = true;
+        if (arg[0] == '-')
+        {
+            char *opt = arg + 1;
+
+            if ((opt[0] == '-' && opt[1] == 'h' && opt[2] == 'e') ||
+                opt[0] == '?')
+            {
+                optShowHelp = true;
+                break;
+            }
+            else
+            if (opt[0] == '-')
+                opt++;
+
+            if (opt[0] == 'g')
+                optUseShaders = true;
+            else
+            if (opt[0] == 'w')
+                optWidth = atoi(opt + 1);
+            else
+            if (opt[0] == 'h')
+                optHeight = atoi(opt + 1);
+        }
     }
 
     if (optShowHelp)
     {
         printf(
-            "Usage: %s [glsl]\n"
-            "glsl argument will turn on GLSL shader mode instead of basic OpenGL lighting.\n"
-            , argv[0]);
+            "Usage: %s [options]\n"
+            "-?          Show this help\n"
+            "-g          Use GLSL shader instead of basic OpenGL lighting\n"
+            "-w<width>   Window width (default %d)\n"
+            "-h<height>  Window height (default %d)\n"
+            "\n",
+            argv[0],
+            SET_DEF_WIDTH, SET_DEF_HEIGHT
+            );
+
         goto exit;
     }
 
@@ -330,7 +365,7 @@
     }
 
     // Initialize SDL + OpenGL
-    if (!dmInitSDLGL(1280, 960, "GLXDragon2"))
+    if (!dmInitSDLGL(optWidth, optHeight, "GLXDragon2"))
         goto exit;
 
     // According to our mode ..