fg_time.cxx: Removed call to ctime() in a printf() which should be harmless

  but seems to be triggering a bug.
light.cxx: Added code to adjust fog color based on sunrise/sunset effects
  and view orientation.  This is an attempt to match the fog color to the
  sky color in the center of the screen.  You see discrepancies at the
  edges, but what else can be done?
sunpos.cxx: Caculate local direction to sun here.  (what compass direction
  do we need to face to point directly at sun)

diff --git a/Time/fg_time.cxx b/Time/fg_time.cxx
index 3de54c3d35c8abeed553ea3bc738be9f0e16280c..c9abf8259381a5cf9c95b2dc819cf71201d8b241 100644 (file)
--- a/Time/fg_time.cxx
+++ b/Time/fg_time.cxx
@@ -268,7 +268,9 @@ time_t get_start_gmt(int year) {
     long int start = mktime(&mt);
 
     fgPrintf( FG_EVENT, FG_DEBUG, "start1 = %ld\n", start);
-    fgPrintf( FG_EVENT, FG_DEBUG, "start2 = %s", ctime(&start));
+    // the ctime() call can screw up time progression on some versions
+    // of Linux
+    // fgPrintf( FG_EVENT, FG_DEBUG, "start2 = %s", ctime(&start));
     fgPrintf( FG_EVENT, FG_DEBUG, "(tm_isdst = %d)\n", mt.tm_isdst);
 
     timezone = fix_up_timezone( timezone );
@@ -407,6 +409,16 @@ void fgTimeUpdate(fgFLIGHT *f, fgTIME *t) {
 
 
 // $Log$
+// Revision 1.11  1998/07/22 21:45:37  curt
+// fg_time.cxx: Removed call to ctime() in a printf() which should be harmless
+//   but seems to be triggering a bug.
+// light.cxx: Added code to adjust fog color based on sunrise/sunset effects
+//   and view orientation.  This is an attempt to match the fog color to the
+//   sky color in the center of the screen.  You see discrepancies at the
+//   edges, but what else can be done?
+// sunpos.cxx: Caculate local direction to sun here.  (what compass direction
+//   do we need to face to point directly at sun)
+//
 // Revision 1.10  1998/07/13 21:02:07  curt
 // Wrote access functions for current fgOPTIONS.
 //

diff --git a/Time/light.cxx b/Time/light.cxx
index 92872e7e1ab00a2bbcbf64133a3c37afc8e39e86..2a6364bddaa8b1e13445ca14f38d872600250c16 100644 (file)
--- a/Time/light.cxx
+++ b/Time/light.cxx
@@ -35,6 +35,7 @@
 
 #include <string.h>
 
+#include <Aircraft/aircraft.h>
 #include <Debug/fg_debug.h>
 #include <Include/fg_constants.h>
 #include <Main/options.hxx>
@@ -89,6 +90,7 @@ void fgLIGHT::Init( void ) {
 
 // update lighting parameters based on current sun position
 void fgLIGHT::Update( void ) {
+    fgFLIGHT *f;
     fgTIME *t;
     fgVIEW *v;
     // if the 4th field is 0.0, this specifies a direction ...
@@ -99,6 +101,7 @@ void fgLIGHT::Update( void ) {
     GLfloat base_fog_color[4] = {0.90, 0.90, 1.00, 1.0};
     double deg, ambient, diffuse, sky_brightness;
 
+    f = current_aircraft.flight;
     t = &cur_time_params;
     v = &current_view;
 
@@ -132,17 +135,80 @@ void fgLIGHT::Update( void ) {
     scene_diffuse[1] = white[1] * diffuse;
     scene_diffuse[2] = white[2] * diffuse;
 
+    // set sky color
+    sky_color[0] = base_sky_color[0] * sky_brightness;
+    sky_color[1] = base_sky_color[1] * sky_brightness;
+    sky_color[2] = base_sky_color[2] * sky_brightness;
+    sky_color[3] = base_sky_color[3];
+
     // set fog color
     fog_color[0] = base_fog_color[0] * sky_brightness;
     fog_color[1] = base_fog_color[1] * sky_brightness;
     fog_color[2] = base_fog_color[2] * sky_brightness;
     fog_color[3] = base_fog_color[3];
+}
 
-    // set sky color
-    sky_color[0] = base_sky_color[0] * sky_brightness;
-    sky_color[1] = base_sky_color[1] * sky_brightness;
-    sky_color[2] = base_sky_color[2] * sky_brightness;
-    sky_color[3] = base_sky_color[3];
+
+// calculate fog color adjusted for sunrise/sunset effects
+void fgLIGHT::UpdateAdjFog( void ) {
+    fgFLIGHT *f;
+    fgVIEW *v;
+    double sun_angle_deg, rotation, param1[3], param2[3];
+
+    f = current_aircraft.flight;
+    v = &current_view;
+
+    fgPrintf( FG_EVENT, FG_DEBUG, "Updating adjusted fog parameters.\n" );
+
+    // set fog color (we'll try to match the sunset color in the
+    // direction we are looking
+
+    // first determine the difference between our view angle and local
+    // direction to the sun
+    rotation = -(sun_rotation + FG_PI) - (FG_Psi - v->view_offset) ;
+    while ( rotation < 0 ) {
+       rotation += FG_2PI;
+    }
+    while ( rotation > FG_2PI ) {
+       rotation -= FG_2PI;
+    }
+    rotation *= RAD_TO_DEG;
+    fgPrintf( FG_EVENT, FG_INFO, 
+             "  View to sun difference in degrees = %.2f\n", rotation);
+
+    // next check if we are in a sunset/sunrise situation
+    sun_angle_deg = sun_angle * RAD_TO_DEG;
+    if ( (sun_angle_deg > 80.0) && (sun_angle_deg < 100.0) ) {
+       /* 0.0 - 0.4 */
+       param1[0] = (10.0 - fabs(90.0 - sun_angle_deg)) / 25.0;
+       param1[1] = (10.0 - fabs(90.0 - sun_angle_deg)) / 35.0;
+       param1[2] = 0.0;
+    } else {
+       param1[0] = param1[1] = param1[2] = 0.0;
+    }
+
+    if ( rotation - 180.0 <= 0.0 ) {
+       param2[0] = param1[0] * (180.0 - rotation) / 180.0;
+       param2[1] = param1[1] * (180.0 - rotation) / 180.0;
+       param2[2] = param1[2] * (180.0 - rotation) / 180.0;
+       printf("param1[0] = %.2f param2[0] = %.2f\n", param1[0], param2[0]);
+    } else {
+       param2[0] = param1[0] * (rotation - 180.0) / 180.0;
+       param2[1] = param1[1] * (rotation - 180.0) / 180.0;
+       param2[2] = param1[2] * (rotation - 180.0) / 180.0;
+       printf("param1[0] = %.2f param2[0] = %.2f\n", param1[0], param2[0]);
+    }
+
+    adj_fog_color[0] = fog_color[0] + param2[0];
+    if ( adj_fog_color[0] > 1.0 ) { adj_fog_color[0] = 1.0; }
+
+    adj_fog_color[1] = fog_color[1] + param2[1];
+    if ( adj_fog_color[1] > 1.0 ) { adj_fog_color[1] = 1.0; }
+
+    adj_fog_color[2] = fog_color[2] + param2[2];
+    if ( adj_fog_color[2] > 1.0 ) { adj_fog_color[2] = 1.0; }
+
+    adj_fog_color[3] = fog_color[3];
 }
 
 
@@ -161,6 +227,16 @@ void fgLightUpdate ( void ) {
 
 
 // $Log$
+// Revision 1.12  1998/07/22 21:45:38  curt
+// fg_time.cxx: Removed call to ctime() in a printf() which should be harmless
+//   but seems to be triggering a bug.
+// light.cxx: Added code to adjust fog color based on sunrise/sunset effects
+//   and view orientation.  This is an attempt to match the fog color to the
+//   sky color in the center of the screen.  You see discrepancies at the
+//   edges, but what else can be done?
+// sunpos.cxx: Caculate local direction to sun here.  (what compass direction
+//   do we need to face to point directly at sun)
+//
 // Revision 1.11  1998/07/13 21:02:08  curt
 // Wrote access functions for current fgOPTIONS.
 //

diff --git a/Time/light.hxx b/Time/light.hxx
index a9a77b5410a56938cb7dec712cae81910ce09845..4b9d9299cb5cc1a5913afa5a37670ec8227d7bd4 100644 (file)
--- a/Time/light.hxx
+++ b/Time/light.hxx
@@ -70,9 +70,15 @@ public:
     // inverse (in view coordinates)
     GLfloat sun_vec_inv[4];
 
-    // the angle between the sun and the local horizontal
+    // the angle between the sun and the local horizontal (in radians)
     double sun_angle;
 
+    // the rotation around our vertical axis of the sun (relative to
+    // due south with positive numbers going in the counter clockwise
+    // direction.)  This is the direction we'd need to face if we
+    // wanted to travel towards the sun.
+    double sun_rotation;
+
     ///////////////////////////////////////////////////////////
     // Derived lighting values
 
@@ -85,6 +91,9 @@ public:
     // fog color
     GLfloat fog_color[4];
 
+    // fog color adjusted for sunset effects
+    GLfloat adj_fog_color[4];
+
     // clear screen color
     GLfloat sky_color[4];
 
@@ -97,6 +106,9 @@ public:
     // update lighting parameters based on current sun position
     void Update( void);
 
+    // calculate fog color adjusted for sunrise/sunset effects
+    void UpdateAdjFog( void );
+
     // Destructor
     ~fgLIGHT( void );
 };
@@ -114,6 +126,16 @@ void fgLightUpdate ( void );
 
 
 // $Log$
+// Revision 1.6  1998/07/22 21:45:39  curt
+// fg_time.cxx: Removed call to ctime() in a printf() which should be harmless
+//   but seems to be triggering a bug.
+// light.cxx: Added code to adjust fog color based on sunrise/sunset effects
+//   and view orientation.  This is an attempt to match the fog color to the
+//   sky color in the center of the screen.  You see discrepancies at the
+//   edges, but what else can be done?
+// sunpos.cxx: Caculate local direction to sun here.  (what compass direction
+//   do we need to face to point directly at sun)
+//
 // Revision 1.5  1998/07/08 14:48:39  curt
 // polar3d.h renamed to polar3d.hxx
 //

diff --git a/Time/sunpos.cxx b/Time/sunpos.cxx
index 4bb75a5f1d7b236606a29e37570cc2be7e59e537..8b3a65bfe4f5709c3a81afd422549d125374b449 100644 (file)
--- a/Time/sunpos.cxx
+++ b/Time/sunpos.cxx
@@ -277,6 +277,7 @@ void fgUpdateSunPos( void ) {
     fgVIEW *v;
     MAT3vec nup, nsun, v0;
     fgPoint3d p;
+    double dot, east_dot;
     double sun_gd_lat, sl_radius;
     double ntmp;
 
@@ -311,8 +312,8 @@ void fgUpdateSunPos( void ) {
     l->sun_vec[3] = 0.0;
     l->sun_vec_inv[3] = 0.0;
 
-    printf("  l->sun_vec = %.2f %.2f %.2f\n", l->sun_vec[0], l->sun_vec[1],
-          l->sun_vec[2]);
+    // printf("  l->sun_vec = %.2f %.2f %.2f\n", l->sun_vec[0], l->sun_vec[1],
+    //        l->sun_vec[2]);
 
     // calculate the sun's relative angle to local up
     MAT3_COPY_VEC(nup, v->local_up);
@@ -323,8 +324,8 @@ void fgUpdateSunPos( void ) {
     MAT3_NORMALIZE_VEC(nsun, ntmp);
 
     l->sun_angle = acos(MAT3_DOT_PRODUCT(nup, nsun));
-    printf("  SUN ANGLE relative to current location = %.3f rads.\n", 
-          l->sun_angle);
+    // printf("  SUN ANGLE relative to current location = %.3f rads.\n", 
+    //        l->sun_angle);
     
     // calculate vector to sun's position on the earth's surface
     v->to_sun[0] = l->fg_sunpos.x - (v->view_pos.x + scenery.center.x);
@@ -346,10 +347,39 @@ void fgUpdateSunPos( void ) {
     //        v->surface_to_sun[0], v->surface_to_sun[1], v->surface_to_sun[2]);
     // printf("Should be close to zero = %.2f\n", 
     //        MAT3_DOT_PRODUCT(v->local_up, v->surface_to_sun));
+
+    // calculate the angle between v->surface_to_sun and
+    // v->surface_east.  We do this so we can sort out the acos()
+    // ambiguity.  I wish I could think of a more efficient way ... :-(
+    east_dot = MAT3_DOT_PRODUCT(v->surface_to_sun, v->surface_east);
+    // printf("  East dot product = %.2f\n", east_dot);
+
+    // calculate the angle between v->surface_to_sun and
+    // v->surface_south.  this is how much we have to rotate the sky
+    // for it to align with the sun
+    dot = MAT3_DOT_PRODUCT(v->surface_to_sun, v->surface_south);
+    // printf("  Dot product = %.2f\n", dot);
+    if ( east_dot >= 0 ) {
+       l->sun_rotation = acos(dot);
+    } else {
+       l->sun_rotation = -acos(dot);
+    }
+    // printf("  Sky needs to rotate = %.3f rads = %.1f degrees.\n", 
+    //        angle, angle * RAD_TO_DEG); */
 }
 
 
 // $Log$
+// Revision 1.10  1998/07/22 21:45:39  curt
+// fg_time.cxx: Removed call to ctime() in a printf() which should be harmless
+//   but seems to be triggering a bug.
+// light.cxx: Added code to adjust fog color based on sunrise/sunset effects
+//   and view orientation.  This is an attempt to match the fog color to the
+//   sky color in the center of the screen.  You see discrepancies at the
+//   edges, but what else can be done?
+// sunpos.cxx: Caculate local direction to sun here.  (what compass direction
+//   do we need to face to point directly at sun)
+//
 // Revision 1.9  1998/07/08 14:48:39  curt
 // polar3d.h renamed to polar3d.hxx
 //