From 032806000b6606cc26c55f96a3873455e815167c Mon Sep 17 00:00:00 2001
From: curt <curt>
Date: Tue, 8 Sep 1998 15:04:33 +0000
Subject: [PATCH] Optimizations by Norman Vine.

---
 Main/options.cxx |  7 +++++--
 Main/views.cxx   | 21 +++++++++++++++------
 Main/views.hxx   | 19 +++++++++++--------
 3 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/Main/options.cxx b/Main/options.cxx
index ab5be64f3..8ad3b419c 100644
--- a/Main/options.cxx
+++ b/Main/options.cxx
@@ -511,8 +511,8 @@ void fgOPTIONS::usage ( void ) {
     printf("General Options:\n");
     printf("\t--help -h:  print usage\n");
     printf("\t--fg-root=path:  specify the root path for all the data files\n");
-    printf("\t--disable-gamemode:  disable full-screen game mode\n");
-    printf("\t--enable-gamemode:  enable full-screen game mode\n");
+    printf("\t--disable-game-mode:  disable full-screen game mode\n");
+    printf("\t--enable-game-mode:  enable full-screen game mode\n");
     printf("\t--disable-splash-screen:  disable splash screen\n");
     printf("\t--enable-splash-screen:  enable splash screen\n");
     printf("\t--disable-intro-music:  disable introduction music\n");
@@ -579,6 +579,9 @@ fgOPTIONS::~fgOPTIONS( void ) {
 
 
 // $Log$
+// Revision 1.24  1998/09/08 15:04:33  curt
+// Optimizations by Norman Vine.
+//
 // Revision 1.23  1998/08/27 17:02:07  curt
 // Contributions from Bernie Bright <bbright@c031.aone.net.au>
 // - use strings for fg_root and airport_id and added methods to return
diff --git a/Main/views.cxx b/Main/views.cxx
index 096c349c4..6d21d920c 100644
--- a/Main/views.cxx
+++ b/Main/views.cxx
@@ -59,7 +59,7 @@ void fgVIEW::Init( void ) {
     winWidth = 640;  // FG_DEFAULT_WIN_WIDTH
     winHeight = 480; // FG_DEFAULT_WIN_HEIGHT
     win_ratio = (double) winWidth / (double) winHeight;
-    update_fov = TRUE;
+    update_fov = true;
 }
 
 
@@ -75,18 +75,24 @@ void fgVIEW::UpdateFOV( fgOPTIONS *o ) {
     // printf("theta_x = %.2f\n", theta_x);
     sin_fov_x = sin(theta_x);
     cos_fov_x = cos(theta_x);
-    slope_x =  - cos_fov_x / sin_fov_x;
-    // (HUH?) sin_fov_x /= slope_x;
+    slope_x =  -cos_fov_x / sin_fov_x;
     // printf("slope_x = %.2f\n", slope_x);
 
+#if defined( USE_FAST_FOV_CLIP )
+    fov_x_clip = slope_x*cos_fov_x - sin_fov_x;
+#endif // defined( USE_FAST_FOV_CLIP )
+
     // calculate sin() and cos() of fov / 2 in Y direction;
     theta_y = (fov * DEG_TO_RAD) / 2.0;
     // printf("theta_y = %.2f\n", theta_y);
     sin_fov_y = sin(theta_y);
     cos_fov_y = cos(theta_y);
     slope_y = cos_fov_y / sin_fov_y;
-    // (HUH?) sin_fov_y /= slope_y;
     // printf("slope_y = %.2f\n", slope_y);
+
+#if defined( USE_FAST_FOV_CLIP )
+    fov_y_clip = -(slope_y*cos_fov_y + sin_fov_y);	
+#endif // defined( USE_FAST_FOV_CLIP )
 }
 
 
@@ -249,10 +255,10 @@ void fgVIEW::UpdateViewMath( fgFLIGHT *f ) {
     MAT3mat R, TMP, UP, LOCAL, VIEW;
     double ntmp;
 
-    if(update_fov == TRUE) {
+    if(update_fov == true) {
 	// printf("Updating fov\n");
 	UpdateFOV(&current_options);
-	update_fov = FALSE;
+	update_fov = false;
     }
 		
     scenery.center.x = scenery.next_center.x;
@@ -538,6 +544,9 @@ fgVIEW::~fgVIEW( void ) {
 
 
 // $Log$
+// Revision 1.20  1998/09/08 15:04:35  curt
+// Optimizations by Norman Vine.
+//
 // Revision 1.19  1998/08/20 20:32:34  curt
 // Reshuffled some of the code in and around views.[ch]xx
 //
diff --git a/Main/views.hxx b/Main/views.hxx
index 77acb063c..dfd1d5d74 100644
--- a/Main/views.hxx
+++ b/Main/views.hxx
@@ -40,14 +40,10 @@
 
 #include "options.hxx"
 
-#ifndef BOOL
-#define BOOL int
-#endif
 
-#ifndef TRUE
-#define FALSE 0
-#define TRUE 1
-#endif
+// used in views.cxx and tilemgr.cxx
+#define USE_FAST_FOV_CLIP 
+
 
 // Define a structure containing view information
 class fgVIEW {
@@ -61,7 +57,7 @@ public:
     double goal_view_offset;
 
     // flag forcing update of fov related stuff
-    BOOL update_fov;
+    bool update_fov;
 	
     // fov of view is specified in the y direction, win_ratio is used to
     // calculate the fov in the X direction = width/height
@@ -83,6 +79,10 @@ public:
     // slope of view frustum edge in eye space X axis
     double slope_x;
 
+#if defined( USE_FAST_FOV_CLIP )
+    double fov_x_clip, fov_y_clip;
+#endif // USE_FAST_FOV_CLIP
+
     // View frustum cull ratio (% of tiles culled ... used for
     // reporting purposes)
     double vfc_ratio;
@@ -181,6 +181,9 @@ extern fgVIEW current_view;
 
 
 // $Log$
+// Revision 1.13  1998/09/08 15:04:36  curt
+// Optimizations by Norman Vine.
+//
 // Revision 1.12  1998/08/24 20:11:15  curt
 // Added i/I to toggle full vs. minimal HUD.
 // Added a --hud-tris vs --hud-culled option.
-- 
2.39.2