Initial revision.

diff --git a/simgear/sky/cloud.cxx b/simgear/sky/cloud.cxx
new file mode 100644 (file)
index 0000000..147f807
--- /dev/null
+++ b/simgear/sky/cloud.cxx
@@ -0,0 +1,180 @@
+// cloud.cxx -- model a single cloud layer
+//
+// Written by Curtis Olson, started June 2000.
+//
+// Copyright (C) 2000  Curtis L. Olson  - curt@flightgear.org
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+//
+// $Id$
+
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <stdio.h>
+#include <iostream>
+
+#include <plib/ssg.h>
+
+#include <simgear/constants.h>
+
+#include "cloud.hxx"
+
+
+// Constructor
+SGCloudLayer::SGCloudLayer( void ) {
+}
+
+
+// Destructor
+SGCloudLayer::~SGCloudLayer( void ) {
+}
+
+
+// build the moon object
+ssgBranch * SGCloudLayer::build( FGPath path, double size, double asl ) {
+
+    layer_asl = asl;
+
+    // set up the cloud state
+    path.append( "cloud.rgba" );
+    layer_state = new ssgSimpleState();
+    layer_state->setTexture( (char *)path.c_str() );
+    layer_state->setShadeModel( GL_SMOOTH );
+    layer_state->disable( GL_LIGHTING );
+    layer_state->disable( GL_CULL_FACE );
+    layer_state->enable( GL_TEXTURE_2D );
+    layer_state->enable( GL_COLOR_MATERIAL );
+    layer_state->setColourMaterial( GL_AMBIENT_AND_DIFFUSE );
+    layer_state->setMaterial( GL_EMISSION, 0, 0, 0, 1 );
+    layer_state->setMaterial( GL_SPECULAR, 0, 0, 0, 1 );
+    layer_state->enable( GL_BLEND );
+    layer_state->enable( GL_ALPHA_TEST );
+    layer_state->setAlphaClamp( 0.01 );
+
+    cl = new ssgColourArray( 4 );
+    vl = new ssgVertexArray( 4 );
+    tl = new ssgTexCoordArray( 4 );
+
+    // build the cloud layer
+    sgVec4 color;
+    sgVec3 vertex;
+    sgVec2 tc;
+    sgSetVec4( color, 1.0f, 1.0f, 1.0f, 1.0f );
+
+    sgSetVec3( vertex, -size, -size, 0.0f );
+    sgSetVec2( tc, 0.0f, 0.0f );
+    cl->add( color );
+    vl->add( vertex );
+    tl->add( tc );
+
+    sgSetVec3( vertex, size, -size, 0.0f );
+    sgSetVec2( tc, size / 1000.0f, 0.0f );
+    cl->add( color );
+    vl->add( vertex );
+    tl->add( tc );
+
+    sgSetVec3( vertex, -size, size, 0.0f );
+    sgSetVec2( tc, 0.0f, size / 1000.0f );
+    cl->add( color );
+    vl->add( vertex );
+    tl->add( tc );
+
+    sgSetVec3( vertex, size, size, 0.0f );
+    sgSetVec2( tc, size / 1000.0f, size / 1000.0f );
+    cl->add( color );
+    vl->add( vertex );
+    tl->add( tc );
+
+    ssgLeaf *layer = 
+       new ssgVtxTable ( GL_TRIANGLE_STRIP, vl, NULL, tl, cl );
+    layer->setState( layer_state );
+
+    // force a repaint of the moon colors with arbitrary defaults
+    repaint( color );
+
+    // build the ssg scene graph sub tree for the sky and connected
+    // into the provide scene graph branch
+    layer_transform = new ssgTransform;
+
+    // moon_transform->addKid( halo );
+    layer_transform->addKid( layer );
+
+    return layer_transform;
+}
+
+
+// repaint the cloud layer colors
+bool SGCloudLayer::repaint( sgVec3 fog_color ) {
+    float *color;
+
+    for ( int i = 0; i < 4; ++i ) {
+       color = cl->get( i );
+       sgCopyVec4( color, fog_color );
+    }
+
+    return true;
+}
+
+
+// reposition the cloud layer at the specified origin and orientation
+// lon specifies a rotation about the Z axis
+// lat specifies a rotation about the new Y axis
+// spin specifies a rotation about the new Z axis (and orients the
+// sunrise/set effects
+bool SGCloudLayer::reposition( sgVec3 p, sgVec3 up, double lon, double lat ) {
+    sgMat4 T1, LON, LAT;
+    sgVec3 axis;
+
+    // combine p and asl (meters) to get translation offset
+    sgVec3 asl_offset;
+    sgCopyVec3( asl_offset, up );
+    sgNormalizeVec3( asl_offset );
+    sgScaleVec3( asl_offset, layer_asl );
+    // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
+    //      << "," << asl_offset[2] << endl;
+    sgAddVec3( asl_offset, p );
+    // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
+    //      << "," << asl_offset[2] << endl;
+
+    // Translate to zero elevation
+    // Point3D zero_elev = current_view.get_cur_zero_elev();
+    // xglTranslatef( zero_elev.x(), zero_elev.y(), zero_elev.z() );
+    sgMakeTransMat4( T1, asl_offset );
+
+    // printf("  Translated to %.2f %.2f %.2f\n", 
+    //        zero_elev.x, zero_elev.y, zero_elev.z );
+
+    // Rotate to proper orientation
+    // printf("  lon = %.2f  lat = %.2f\n", FG_Longitude * RAD_TO_DEG,
+    //        FG_Latitude * RAD_TO_DEG);
+    // xglRotatef( f->get_Longitude() * RAD_TO_DEG, 0.0, 0.0, 1.0 );
+    sgSetVec3( axis, 0.0, 0.0, 1.0 );
+    sgMakeRotMat4( LON, lon * RAD_TO_DEG, axis );
+
+    // xglRotatef( 90.0 - f->get_Latitude() * RAD_TO_DEG, 0.0, 1.0, 0.0 );
+    sgSetVec3( axis, 0.0, 1.0, 0.0 );
+    sgMakeRotMat4( LAT, 90.0 - lat * RAD_TO_DEG, axis );
+
+    sgMat4 TRANSFORM;
+
+    sgCopyMat4( TRANSFORM, T1 );
+    sgPreMultMat4( TRANSFORM, LON );
+    sgPreMultMat4( TRANSFORM, LAT );
+
+    sgCoord layerpos;
+    sgSetCoord( &layerpos, TRANSFORM );
+
+    layer_transform->setTransform( &layerpos );
+
+    return true;
+}

diff --git a/simgear/sky/cloud.hxx b/simgear/sky/cloud.hxx
new file mode 100644 (file)
index 0000000..1faabb3
--- /dev/null
+++ b/simgear/sky/cloud.hxx
@@ -0,0 +1,74 @@
+// cloud.hxx -- model a single cloud layer
+//
+// Written by Curtis Olson, started June 2000.
+//
+// Copyright (C) 2000  Curtis L. Olson  - curt@flightgear.org
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+//
+// $Id$
+
+
+#ifndef _SG_CLOUD_HXX_
+#define _SG_CLOUD_HXX_
+
+
+#include <plib/ssg.h>
+
+#include <simgear/misc/fgpath.hxx>
+
+
+class SGCloudLayer {
+
+    ssgTransform *layer_transform;
+    ssgSimpleState *layer_state;
+
+    ssgColourArray *cl; 
+    ssgVertexArray *vl;
+    ssgTexCoordArray *tl;
+
+    float layer_asl;           // height above sea level (meters)
+
+public:
+
+    // Constructor
+    SGCloudLayer( void );
+
+    // Destructor
+    ~SGCloudLayer( void );
+
+    // build the cloud object
+    ssgBranch *build( FGPath path, double size, double asl );
+
+    // repaint the cloud colors based on current value of sun_angle,
+    // sky, and fog colors.  This updates the color arrays for
+    // ssgVtxTable.
+    // sun angle in degrees relative to verticle
+    // 0 degrees = high noon
+    // 90 degrees = sun rise/set
+    // 180 degrees = darkest midnight
+    bool repaint( sgVec3 fog_color );
+
+    // reposition the cloud layer at the specified origin and
+    // orientation
+    // lon specifies a rotation about the Z axis
+    // lat specifies a rotation about the new Y axis
+    // spin specifies a rotation about the new Z axis (and orients the
+    // sunrise/set effects
+    bool reposition( sgVec3 p, sgVec3 up, double lon, double lat );
+};
+
+
+#endif // _SG_CLOUD_HXX_