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fgdata/Shaders/building-default.vert
Stuart Buchanan 119fb5efe2 Random Buildings - improved texture mapping
Previously the front and side faces of random/OSM buildings
had identical texture coordinates.  This resulted in the sides
of buildings texture mapping being squeezed or stretched.

This change generates a separate texture mapping for the sides
of the buildings.
2019-11-23 17:08:04 +00:00

121 lines
5.2 KiB
GLSL

// -*-C++-*-
// Shader that uses OpenGL state values to do per-pixel lighting
//
// The only light used is gl_LightSource[0], which is assumed to be
// directional.
//
// Diffuse colors come from the gl_Color, ambient from the material. This is
// equivalent to osg::Material::DIFFUSE.
#version 120
#extension GL_EXT_draw_instanced : enable
#define MODE_OFF 0
#define MODE_DIFFUSE 1
#define MODE_AMBIENT_AND_DIFFUSE 2
attribute vec3 instancePosition; // (x,y,z)
attribute vec3 instanceScale ; // (width, depth, height)
attribute vec3 rotPitchWtexX0; // (rotation, pitch height, wall texture x0)
attribute vec3 wtexY0FRtexx1FSRtexY1; // (wall texture y0, front/roof texture x1, front/side/roof texture y1)
attribute vec3 rtexX0RtexY0StexX1; // (roof texture x0, roof texture y0, side texture x1)
attribute vec3 rooftopscale; // (rooftop x scale, rooftop y scale)
// The constant term of the lighting equation that doesn't depend on
// the surface normal is passed in gl_{Front,Back}Color. The alpha
// component is set to 1 for front, 0 for back in order to work around
// bugs with gl_FrontFacing in the fragment shader.
varying vec4 diffuse_term;
varying vec3 normal;
uniform int colorMode;
////fog "include"////////
//uniform int fogType;
//
//void fog_Func(int type);
/////////////////////////
void main()
{
// Determine the rotation for the building.
float sr = sin(6.28 * rotPitchWtexX0.x);
float cr = cos(6.28 * rotPitchWtexX0.x);
vec3 position = gl_Vertex.xyz;
// Adjust the very top of the roof to match the rooftop scaling. This shapes
// the rooftop - gambled, gabled etc. These vertices are identified by gl_Color.z
position.x = (1.0 - gl_Color.z) * position.x + gl_Color.z * ((position.x + 0.5) * rooftopscale.x - 0.5);
position.y = (1.0 - gl_Color.z) * position.y + gl_Color.z * (position.y * rooftopscale.y);
// Adjust pitch of roof to the correct height. These vertices are identified by gl_Color.z
// Scale down by the building height (instanceScale.z) because
// immediately afterwards we will scale UP the vertex to the correct scale.
position.z = position.z + gl_Color.z * rotPitchWtexX0.y / instanceScale.z;
position = position * instanceScale.xyz;
// Rotation of the building and movement into position
position.xy = vec2(dot(position.xy, vec2(cr, sr)), dot(position.xy, vec2(-sr, cr)));
position = position + instancePosition.xyz;
gl_Position = gl_ModelViewProjectionMatrix * vec4(position,1.0);
// Texture coordinates are stored as:
// - a separate offset (x0, y0) for the wall (wtex0x, wtex0y), and roof (rtex0x, rtex0y)
// - a semi-shared (x1, y1) so that the front and side of the building can have
// different texture mappings
//
// The vertex color value selects between them:
// gl_Color.x=1 indicates front/back walls
// gl_Color.y=1 indicates roof
// gl_Color.z=1 indicates top roof vertexs (used above)
// gl_Color.a=1 indicates sides
// Finally, the roof texture is on the right of the texture sheet
float wtex0x = rotPitchWtexX0.z; // Front/Side texture X0
float wtex0y = wtexY0FRtexx1FSRtexY1.x; // Front/Side texture Y0
float rtex0x = rtexX0RtexY0StexX1.x; // Roof texture X0
float rtex0y = rtexX0RtexY0StexX1.y; // Roof texture Y0
float wtex1x = wtexY0FRtexx1FSRtexY1.y; // Front/Roof texture X1
float stex1x = rtexX0RtexY0StexX1.z; // Side texture X1
float wtex1y = wtexY0FRtexx1FSRtexY1.z; // Front/Roof/Side texture Y1
vec2 tex0 = vec2(sign(gl_MultiTexCoord0.x) * (gl_Color.x*wtex0x + gl_Color.y*rtex0x + gl_Color.a*wtex0x),
gl_Color.x*wtex0y + gl_Color.y*rtex0y + gl_Color.a*wtex0y);
vec2 tex1 = vec2(gl_Color.x*wtex1x + gl_Color.y*wtex1x + gl_Color.a*stex1x,
wtex1y);
gl_TexCoord[0].x = tex0.x + gl_MultiTexCoord0.x * tex1.x;
gl_TexCoord[0].y = tex0.y + gl_MultiTexCoord0.y * tex1.y;
// Rotate the normal.
normal = gl_Normal;
normal.xy = vec2(dot(normal.xy, vec2(cr, sr)), dot(normal.xy, vec2(-sr, cr)));
normal = gl_NormalMatrix * normal;
vec4 ambient_color, diffuse_color;
if (colorMode == MODE_DIFFUSE) {
diffuse_color = vec4(1.0,1.0,1.0,1.0);
ambient_color = gl_FrontMaterial.ambient;
} else if (colorMode == MODE_AMBIENT_AND_DIFFUSE) {
diffuse_color = vec4(1.0,1.0,1.0,1.0);
ambient_color = vec4(1.0,1.0,1.0,1.0);
} else {
diffuse_color = gl_FrontMaterial.diffuse;
ambient_color = gl_FrontMaterial.ambient;
}
diffuse_term = diffuse_color * gl_LightSource[0].diffuse;
vec4 constant_term = gl_FrontMaterial.emission + ambient_color *
(gl_LightModel.ambient + gl_LightSource[0].ambient);
// Super hack: if diffuse material alpha is less than 1, assume a
// transparency animation is at work
if (gl_FrontMaterial.diffuse.a < 1.0)
diffuse_term.a = gl_FrontMaterial.diffuse.a;
else
diffuse_term.a = 1.0;
// Another hack for supporting two-sided lighting without using
// gl_FrontFacing in the fragment shader.
gl_FrontColor.rgb = constant_term.rgb; gl_FrontColor.a = 1.0;
gl_BackColor.rgb = constant_term.rgb; gl_BackColor.a = 0.0;
//fogCoord = abs(ecPosition.z / ecPosition.w);
//fog_Func(fogType);
}