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fgdata/Compositor/Shaders/Default/wake.vert
2019-10-26 01:42:48 +02:00

70 lines
2.3 KiB
GLSL

// This shader is mostly an adaptation of the shader found at
// http://www.bonzaisoftware.com/water_tut.html and its glsl conversion
// available at http://forum.bonzaisoftware.com/viewthread.php?tid=10
// © Michael Horsch - 2005
// Major update and revisions - 2011-10-07
// © Emilian Huminiuc and Vivian Meazza
// Optimisation - 2012-5-05
// © Emilian Huminiuc and Vivian Meazza
#version 120
#define fps2kts 0.5925
varying vec4 waterTex1;
varying vec4 waterTex2;
varying vec3 viewerdir;
varying vec3 lightdir;
varying vec3 normal;
uniform float osg_SimulationTime;
uniform float WindE, WindN, spd, hdg;
/////////////////////////
/////// functions /////////
void relWind(out float rel_wind_speed_kts, float rel_wind_from_deg)
{
//calculate the carrier speed north and east in kts
float speed_north_kts = cos(radians(hdg)) * spd ;
float speed_east_kts = sin(radians(hdg)) * spd ;
//calculate the relative wind speed north and east in kts
float rel_wind_speed_from_east_kts = WindE*fps2kts + speed_east_kts;
float rel_wind_speed_from_north_kts = WindN*fps2kts + speed_north_kts;
//combine relative speeds north and east to get relative windspeed in kts
rel_wind_speed_kts = sqrt((rel_wind_speed_from_east_kts * rel_wind_speed_from_east_kts) + (rel_wind_speed_from_north_kts * rel_wind_speed_from_north_kts));
//calculate the relative wind direction
rel_wind_from_deg = degrees(atan(rel_wind_speed_from_east_kts, rel_wind_speed_from_north_kts));
}
void main(void)
{
float relWindspd=0;
float relWinddir=0;
//compute relative wind speed and direction
relWind (relWindspd, relWinddir);
vec3 N = normalize(gl_Normal);
normal = N;
viewerdir = vec3(gl_ModelViewMatrixInverse[3]) - vec3(gl_Vertex);
lightdir = normalize(vec3(gl_ModelViewMatrixInverse * gl_LightSource[0].position));
vec4 t1 = vec4(osg_SimulationTime*0.005217, 0.0, 0.0, 0.0);
vec4 t2 = vec4(osg_SimulationTime*-0.0012, 0.0, 0.0, 0.0);
float windFactor = -relWindspd * 0.1;
// float windFactor = sqrt(pow(abs(WindE),2)+pow(abs(WindN),2)) * 0.6;
waterTex1 = gl_MultiTexCoord0 + t1 * windFactor;
waterTex2 = gl_MultiTexCoord0 + t2 * windFactor;
gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0;
gl_Position = ftransform();
}