Added btCudaBroadphase, some early research & development work to accelerate Bullet using CUDA

Re-uses the NVidia particle demo.

Extras/CUDA/paramgl.h

@@ -0,0 +1,54 @@
+/*
+    ParamListGL
+    - class derived from ParamList to do simple OpenGL rendering of a parameter list
+    sgg 8/2001
+*/
+
+#ifndef PARAMGL_H
+#define PARAMGL_H
+
+#if defined(__APPLE__) || defined(MACOSX)
+#include <GLUT/glut.h>
+#else
+#include <GL/glut.h>
+#endif
+
+#include <param.h>
+
+void beginWinCoords();
+void endWinCoords();
+void glPrint(int x, int y, const char *s, void *font);
+void glPrintShadowed(int x, int y, const char *s, void *font, float *color);
+
+class ParamListGL : public ParamList {
+public:
+  ParamListGL(char *name = "");
+
+  void Render(int x, int y, bool shadow = false);
+  bool Mouse(int x, int y, int button=GLUT_LEFT_BUTTON, int state=GLUT_DOWN);
+  bool Motion(int x, int y);
+  void Special(int key, int x, int y);
+
+  void SetSelectedColor(float r, float g, float b) { text_col_selected[0] = r; text_col_selected[1] = g; text_col_selected[2] = b; }
+  void SetUnSelectedColor(float r, float g, float b) { text_col_unselected[0] = r; text_col_unselected[1] = g; text_col_unselected[2] = b; }
+
+  int bar_x;
+  int bar_w;
+  int bar_h;
+  int text_x;
+  int separation;
+  int value_x;
+  int font_h;
+  int start_x, start_y;
+  int bar_offset;
+
+  float text_col_selected[3];
+  float text_col_unselected[3];
+  float text_col_shadow[3];
+  float bar_col_outer[3];
+  float bar_col_inner[3];
+
+  void *font;
+};
+
+#endif