Initialize some variables before using them

[simgear.git] / simgear / scene / sky / oursun.cxx

diff --git a/simgear/scene/sky/oursun.cxx b/simgear/scene/sky/oursun.cxx
index 3ffd6538f7c37e8289bc5a4fee71a4c8d6d75ee7..923ae3f832b2b81a4f8c962c8e5441873e21eaf7 100644 (file)
--- a/simgear/scene/sky/oursun.cxx
+++ b/simgear/scene/sky/oursun.cxx
@@ -44,10 +44,11 @@
 #  include <plib/ssgaLensFlare.h>
 #endif
 
+#include <simgear/screen/colors.hxx>
+
 #include "sphere.hxx"
 #include "oursun.hxx"
 
-
 // Set up sun rendering call backs
 static int sgSunOrbPreDraw( ssgEntity *e ) {
     /* cout << endl << "Sun orb pre draw" << endl << "----------------" 
@@ -89,7 +90,8 @@ static int sgSunHaloPreDraw( ssgEntity *e ) {
     // cout << "push error = " << glGetError() << endl;
 
     glDisable( GL_DEPTH_TEST );
-    glDisable( GL_FOG );
+    // glDisable( GL_FOG );
+    glFogf (GL_FOG_DENSITY, sun_exp2_punch_through);
     glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
 
     return true;
@@ -111,6 +113,8 @@ static int sgSunHaloPostDraw( ssgEntity *e ) {
 
 // Constructor
 SGSun::SGSun( void ) {
+    prev_sun_angle = -9999.0;
+    visibility = -9999.0;
 }
 
 
@@ -149,7 +153,8 @@ static GLuint makeHalo( GLubyte *sun_texbuf, int width ) {
     texSize = width * width;
   
     if ( !sun_texbuf ) {
-       cout << "ouch ..." << endl;
+        SG_LOG( SG_EVENT, SG_ALERT,
+                               "Could not allocate memroy for the sun texture");
        exit(-1);  // Ugly!
     }
 
@@ -256,7 +261,7 @@ ssgBranch * SGSun::build( SGPath path, double sun_size ) {
                                    sgSunOrbPreDraw, sgSunOrbPostDraw );
 
     // force a repaint of the sun colors with arbitrary defaults
-    repaint( 0.0 );
+    repaint( 0.0, 1.0 );
 
     // build the halo
     // sun_texbuf = new GLubyte[64*64*3];
@@ -331,38 +336,38 @@ ssgBranch * SGSun::build( SGPath path, double sun_size ) {
 // 0 degrees = high noon
 // 90 degrees = sun rise/set
 // 180 degrees = darkest midnight
-bool SGSun::repaint( double sun_angle ) {
-    if ( sun_angle * SGD_RADIANS_TO_DEGREES < 100 ) {
-       // else sun is well below horizon (so no point in repainting it)
-    
-       // x_10 = sun_angle^10
-       double x_10 = sun_angle * sun_angle * sun_angle * sun_angle * sun_angle
-           * sun_angle * sun_angle * sun_angle * sun_angle * sun_angle;
-
-       float ambient = (float)(0.4 * pow (1.1, - x_10 / 30.0));
-       if (ambient < 0.3) { ambient = 0.3; }
-       if (ambient > 1.0) { ambient = 1.0; }
-
-       sgVec4 color;
-       sgSetVec4( color,
-                  (ambient * 6.0)  - 1.0, // minimum value = 0.8
-                  (ambient * 11.0) - 3.0, // minimum value = 0.3
-                  (ambient * 12.0) - 3.6, // minimum value = 0.0
-                  1.0 );
-    
-       // temp test, forces the color to always be white
-       // sgSetVec4( color, 1.0, 1.0, 1.0, 1.0 );
-
-       if (color[0] > 1.0) color[0] = 1.0;
-       if (color[1] > 1.0) color[1] = 1.0;
-       if (color[2] > 1.0) color[2] = 1.0;
-
-       // cout << "color = " << color[0] << " " << color[1] << " " 
-       //      << color[2] << endl;
-
-       float *ptr;
-       ptr = cl->get( 0 );
-       sgCopyVec4( ptr, color );
+bool SGSun::repaint( double sun_angle, double new_visibility ) {
+    if ( visibility != new_visibility ) {
+        visibility = new_visibility;
+
+        static double sqrt_m_log01 = sqrt( -log( 0.01 ) );
+        sun_exp2_punch_through = sqrt_m_log01 / (visibility * 15);
+    }
+
+    if (prev_sun_angle != sun_angle) {
+        prev_sun_angle = sun_angle;
+
+        float sun_factor = 4*cos(sun_angle);
+
+        if (sun_factor > 1) sun_factor = 1.0;
+        if (sun_factor < -1) sun_factor = -1.0;
+        sun_factor = sun_factor/2 + 0.5;
+
+        sgVec4 color;
+        color[1] = sqrt(sun_factor);
+        color[0] = sqrt(color[1]);
+        color[2] = sun_factor * sun_factor;
+        color[2] *= color[2];
+        color[3] = 1.0;
+
+        gamma_correct_rgb( color );
+
+        // cout << "color = " << color[0] << " " << color[1] << " "
+        //      << color[2] << endl;
+
+        float *ptr;
+        ptr = cl->get( 0 );
+        sgCopyVec4( ptr, color );
     }
 
     return true;