diff --git a/basegraph.cpp b/basegraph.cpp
index b84f5e19..000fbfa4 100644
--- a/basegraph.cpp
+++ b/basegraph.cpp
@@ -199,31 +199,16 @@ void stereo::set_projection(int ed) {
   
   if(pmodel && !stereo::active()) {
 
-    // simulate glOrtho
-    GLfloat ortho[16] = {
-      GLfloat(2. / vid.xres), 0, 0, 0, 
-      0, GLfloat(-2. / vid.yres), 0, 0, 
-      0, 0, GLfloat(.4 / stereo::scrdist), 0,
-      0, 0, 0, 1};
-      
-    glhr::projection_multiply(glhr::as_glmatrix(ortho));
+    glhr::projection_multiply(glhr::ortho(vid.xres/2, -vid.yres/2, stereo::scrdist/.4));
     }
   else if(pmodel) {
 
-    float lowdepth = .1, hidepth = 1e9;
-    
-    ld right = vid.xres/2 * lowdepth / stereo::scrdist;
+    ld right = vid.xres/2 / stereo::scrdist;
     ld left = -right;
-    ld top = -vid.yres/2 * lowdepth / stereo::scrdist;
+    ld top = -vid.yres/2 / stereo::scrdist;
     ld bottom = -top;
 
-    GLfloat frustum[16] = {
-      GLfloat(2 * lowdepth / (right-left)), 0, 0, 0, 
-      0, GLfloat(2 * lowdepth / (top-bottom)), 0, 0, 
-      0, 0, -(hidepth+lowdepth)/(hidepth-lowdepth), -1,
-      0, 0, -2*lowdepth*hidepth/(hidepth-lowdepth), 0};
-
-    glhr::projection_multiply(glhr::as_glmatrix(frustum));
+    glhr::projection_multiply(glhr::frustum((right-left)/2, (top-bottom)/2));
     
     if(ed) glhr::projection_multiply(glhr::translate(stereo::ipd * vid.radius * ed/2, 0, 0));
 
@@ -233,22 +218,11 @@ void stereo::set_projection(int ed) {
     stereo::scrdist_text = 0;
     }
   else {
-    float lowdepth = .1;
-    float hidepth = 1e9;
-  
-    // simulate glFrustum
-    GLfloat frustum[16] = {
-      GLfloat(vid.yres * 1./vid.xres), 0, 0, 0, 
-      0, 1, 0, 0, 
-      0, 0, -(hidepth+lowdepth)/(hidepth-lowdepth), -1,
-      0, 0, -2*lowdepth*hidepth/(hidepth-lowdepth), 0};
-  
-    glhr::projection_multiply(glhr::as_glmatrix(frustum));
+    glhr::projection_multiply(glhr::frustum(vid.xres * 1. / vid.yres, 1));
 
     GLfloat sc = vid.radius / (vid.yres/2.);
-    GLfloat mat[16] = {sc,0,0,0, 0,-sc,0,0, 0,0,-1,0, 0,0, 0,1};
 
-    glhr::projection_multiply(glhr::as_glmatrix(mat));
+    glhr::projection_multiply(glhr::scale(sc, -sc, -1));
     
     if(ed) glhr::projection_multiply(glhr::translate(stereo::ipd * ed/2, 0, 0));
   
@@ -328,13 +302,6 @@ inline int next_p2 (int a )
     return rval;
 }
 
-void glError(const char* GLcall, const char* file, const int line) {
-  GLenum errCode = glGetError();
-  if(errCode!=GL_NO_ERROR) {
-    fprintf(stderr, "OPENGL ERROR #%i: in file %s on line %i :: %s\n",errCode,file, line, GLcall);
-    }
-  }
-
 #if CAP_GLFONT
 
 struct glfont_t {
diff --git a/rug.cpp b/rug.cpp
index cfeb74ff..920e035a 100644
--- a/rug.cpp
+++ b/rug.cpp
@@ -995,7 +995,7 @@ bool project_ods(hyperpoint azeq, hyperpoint& h1, hyperpoint& h2, bool eye) {
   }
 #endif
 
-vector<GLfloat> vertex_array, tvertex_array;
+vector<GLfloat> vertex_array, tvertex_array, color_array;
 
 void drawTriangle(triangle& t) {
   using namespace hyperpoint_vec;  
@@ -1013,6 +1013,7 @@ void drawTriangle(triangle& t) {
 
     hyperpoint hc = (pts[1] - pts[0]) ^ (pts[2] - pts[0]);  
     double hch = hypot3(hc);
+    
     glNormal3f(hc[0]/hch,hc[1]/hch,hc[2]/hch);
 
     bool ok = true;
@@ -1067,13 +1068,22 @@ void drawTriangle(triangle& t) {
   hyperpoint hc = (h[1] - h[0]) ^ (h[2] - h[0]);  
   double hch = hypot3(hc);
   
+  ld col = (2 + hc[0]/hch) / 3;
+  
+  #if !CAP_SHADER
   glNormal3f(hc[0]/hch,hc[1]/hch,hc[2]/hch);
+  #endif
   
   for(int i: {0,1,2}) {
     tvertex_array.push_back(t.m[i]->x1);
     tvertex_array.push_back(t.m[i]->y1);
     for(int j: {0,1,2})
       vertex_array.push_back(h[i][j]);
+    
+    #if CAP_SHADER
+    for(int a=0; a<3; a++) color_array.push_back(col);
+    color_array.push_back(1);
+    #endif
     }
   }
 
@@ -1123,7 +1133,7 @@ void drawRugScene() {
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   
   glDisable(GL_BLEND);
-  glhr::switch_mode(glhr::gmVarColored);
+  glhr::switch_mode(glhr::gmLightFog);
   glEnable(GL_DEPTH_TEST);
   glDepthFunc(GL_LESS);
   
@@ -1131,32 +1141,22 @@ void drawRugScene() {
     use_precompute = false;
     vertex_array.clear();
     tvertex_array.clear();
+    color_array.clear();
     stereo::set_mask(ed), stereo::set_viewport(ed);
     if(ed == 1 && stereo::mode == stereo::sAnaglyph)
       glClear(GL_DEPTH_BUFFER_BIT);
     
     start_projection(ed);
     if(stereo::mode == stereo::sODS) {
-#ifndef GLES_ONLY
-      glOrtho(-M_PI, M_PI, -M_PI, M_PI, 0, -M_PI * 2);
-#endif
+      glhr::projection_multiply(glhr::ortho(M_PI, M_PI, 2*M_PI));
       }
     else if(rug_perspective || stereo::active()) {
 
-      ld vnear = .001;
-      ld vfar = 1000;
-      ld sca = vnear * stereo::tanfov / vid.xres;
       xview = stereo::tanfov;
       yview = stereo::tanfov * vid.yres / vid.xres;
       
-      //glFrustum(-sca * vid.xres, sca * vid.xres, -sca * vid.yres, sca * vid.yres, vnear, vfar);
-      
-      GLfloat frustum[16] = {
-        GLfloat(vnear / sca / vid.xres), 0, 0, 0,
-        0, GLfloat(vnear / sca / vid.yres), 0, 0,
-        0, 0, GLfloat(-(vnear+vfar)/(vfar-vnear)), -1,
-        0, 0, GLfloat(-2*vnear*vfar/(vfar-vnear)), 1};
-      glhr::projection_multiply(glhr::as_glmatrix(frustum));
+      glhr::projection_multiply(glhr::frustum(xview, yview, .01, 100));
+      xview = -xview; yview = -yview;
 
       if(!rug_perspective) 
         glhr::projection_multiply(glhr::translate(0, 0, -model_distance));
@@ -1177,28 +1177,26 @@ void drawRugScene() {
       yview = stereo::tanfov * model_distance * vid.yres / vid.xres;
       // glOrtho(-xview, xview, yview, -yview, -1000, 1000);
 
-      GLfloat ortho[16] = {
-        GLfloat(1/xview), 0, 0, 0, 
-        0, GLfloat(1/yview), 0, 0, 
-        0, 0, GLfloat(.001), 0,
-        0, 0, 0, 1};
-      glhr::projection_multiply(glhr::as_glmatrix(ortho));
+      glhr::projection_multiply(glhr::ortho(xview, yview, -1000));
       }
     glColor4f(1.f, 1.f, 1.f, 1.f);
     
-    fog_max(
-      gwhere == gSphere ? 10 : 
-      gwhere == gElliptic ? 4 :
+    glhr::fog_max(
+      gwhere == gSphere && rug_perspective ? 10 : 
+      gwhere == gElliptic && rug_perspective ? 4 :
       100
       );
   
     glhr::set_modelview(glhr::id());
-
+    
     for(int t=0; t<size(triangles); t++)
       drawTriangle(triangles[t]);
       
     glhr::vertices(&vertex_array[0], 0);
     glhr::texture_vertices(&tvertex_array[0], 0);
+#if CAP_SHADER
+    glhr::color_vertices(&color_array[0], 0);
+#endif    
     glDrawArrays(GL_TRIANGLES, 0, size(vertex_array)/3);
 
     stereo::set_mask(0);
@@ -1458,8 +1456,8 @@ static const ld RADAR_INF = 1e12;
 ld radar_distance = RADAR_INF;
 
 hyperpoint gethyper(ld x, ld y) {
-  double mx = ((x*2 / vid.xres)-1) * xview;
-  double my = (1-(y*2 / vid.yres)) * yview;
+  double mx = (x - vid.xcenter)/vid.xres * 2 * xview;
+  double my = (vid.ycenter - y)/vid.yres * 2 * yview;
   radar_distance = RADAR_INF;
   
   double rx1=0, ry1=0;
diff --git a/shaders.cpp b/shaders.cpp
index 59e93bd1..4159828e 100644
--- a/shaders.cpp
+++ b/shaders.cpp
@@ -7,6 +7,13 @@
 // #undef CAP_SHADER
 // #define CAP_SHADER 0
 
+void glError(const char* GLcall, const char* file, const int line) {
+  GLenum errCode = glGetError();
+  if(errCode!=GL_NO_ERROR) {
+    fprintf(stderr, "OPENGL ERROR #%i: in file %s on line %i :: %s\n",errCode,file, line, GLcall);
+    }
+  }
+
 namespace glhr {
 
 enum eMode { gmColored, gmTextured, gmVarColored, gmLightFog, gmMAX};
@@ -15,7 +22,11 @@ static const flagtype GF_TEXTURE  = 1;
 static const flagtype GF_VARCOLOR = 2;
 static const flagtype GF_LIGHTFOG = 4;
 
-flagtype flags[gmMAX] = { 0, GF_TEXTURE, GF_VARCOLOR, GF_TEXTURE | GF_LIGHTFOG };
+flagtype flags[gmMAX] = { 0, GF_TEXTURE, GF_VARCOLOR, GF_TEXTURE | GF_LIGHTFOG 
+#if CAP_SHADER
+  | GF_VARCOLOR 
+#endif
+  };
 
 eMode mode;
 
@@ -24,10 +35,20 @@ void switch_mode(eMode m);
 struct glmatrix {
   GLfloat a[4][4];
   GLfloat* operator[] (int i) { return a[i]; }
+  const GLfloat* operator[] (int i) const { return a[i]; }
   GLfloat* as_array() { return a[0]; }
   const GLfloat* as_array() const { return a[0]; }
   };
 
+void display(const glmatrix& m) {
+  for(int i=0; i<4; i++) {
+    for(int j=0; j<4; j++)
+      printf("%10.5f", m[i][j]);
+    printf("\n");
+    }
+  printf("\n");
+  }
+
 glmatrix operator * (glmatrix m1, glmatrix m2) {
   glmatrix res;
   for(int i=0; i<4; i++)
@@ -58,6 +79,24 @@ glmatrix scale(ld x, ld y, ld z) {
   return tmp;
   }
 
+glmatrix ortho(ld x, ld y, ld z) {
+  return scale(1/x, 1/y, 1/z);
+  }
+
+glmatrix& as_glmatrix(GLfloat o[16]) {
+  glmatrix& tmp = (glmatrix&) (o[0]);
+  return tmp;
+  }
+
+glmatrix frustum(ld x, ld y, ld vnear = 1e-3, ld vfar = 1e9) {
+  GLfloat frustum[16] = {
+    GLfloat(1 / x), 0, 0, 0,
+    0, GLfloat(1 / y), 0, 0,
+    0, 0, GLfloat(-(vnear+vfar)/(vfar-vnear)), -1,
+    0, 0, GLfloat(-2*vnear*vfar/(vfar-vnear)), 0};
+  return as_glmatrix(frustum);
+  }
+
 glmatrix translate(ld x, ld y, ld z) {
   glmatrix tmp;
   for(int i=0; i<4; i++)
@@ -69,11 +108,6 @@ glmatrix translate(ld x, ld y, ld z) {
   return tmp;
   }
 
-glmatrix& as_glmatrix(GLfloat o[16]) {
-  glmatrix& tmp = (glmatrix&) (o[0]);
-  return tmp;
-  }
-
 // ** legacy **
 
 #if !CAP_SHADER
@@ -124,11 +158,14 @@ void projection_multiply(const glmatrix& m) {
 
 void init();
 
-int compileShader(int type, const char* s) {
+int compileShader(int type, const string& s) {
   GLint status;
   
+  printf("===\ns%s\n===\n", s.c_str());
+  
   GLint shader = glCreateShader(type);
-  glShaderSource(shader, 1, &s, NULL);
+  const char *ss = s.c_str();
+  glShaderSource(shader, 1, &ss, NULL);
   glCompileShader(shader);
   
   GLint logLength;
@@ -156,7 +193,7 @@ struct GLprogram *current = NULL;
 
 enum {
   UNIFORM_MODELVIEWPROJECTION_MATRIX,
-  UNIFORM_NORMAL_MATRIX,
+  UNIFORM_FOGFACTOR,
   NUM_UNIFORMS
   };
 
@@ -200,8 +237,8 @@ struct GLprogram {
     // glBindAttribLocation(_program, GLKVertexAttribNormal, "normal"); ??
   
     uniforms[UNIFORM_MODELVIEWPROJECTION_MATRIX] = glGetUniformLocation(_program, "modelViewProjectionMatrix");
-    uniforms[UNIFORM_NORMAL_MATRIX] = glGetUniformLocation(_program, "normalMatrix");    
-    printf("uniforms: %d %d\n", uniforms[UNIFORM_MODELVIEWPROJECTION_MATRIX], uniforms[UNIFORM_NORMAL_MATRIX]);
+    uniforms[UNIFORM_FOGFACTOR] = glGetUniformLocation(_program, "fogfactor");    
+    printf("uniforms: %d %d\n", uniforms[UNIFORM_MODELVIEWPROJECTION_MATRIX], uniforms[UNIFORM_FOGFACTOR]);
     }
   
   ~GLprogram() {
@@ -222,13 +259,24 @@ struct GLprogram {
 
 GLprogram *programs[gmMAX];
 
+/*
+string stringbuilder(bool i) { return ""; }
+
+template<class.. T> string stringbuilder(bool i, bool j, T... t) { return stringbuilder(j, t...); }
+template<class.. T> string stringbuilder(bool i, const string& s, T... t) { 
+  if(i) return s + stringbuilder(i, t...);
+  else return stringbuilder(i, t...); 
+  } */
+
 void init() {
   projection = id();
     
-  for(int i=0; i<2; i++) {
-    auto texture_only = [=] (string s) -> string { if(i) return s; else return ""; };
-    auto not_texture_only = [=] (string s) -> string { if(!i) return s; else return ""; };
-   
+  for(int i=0; i<4; i++) {
+    flagtype f = flags[i];
+    flagtype nf = ~f;
+    auto texture_only = [=] (string s) -> string { if(f & GF_TEXTURE) return s; else return ""; };
+    auto not_texture_only = [=] (string s) -> string { if(nf & GF_TEXTURE) return s; else return ""; };
+    
     programs[i] = new GLprogram(
       // "attribute vec4 position;"
       // "attribute vec3 normal;"
@@ -237,7 +285,7 @@ void init() {
       + texture_only( "varying vec2 vTexCoord;" ) +
       
       "uniform mat4 modelViewProjectionMatrix;"
-      "uniform mat3 normalMatrix;"
+      "uniform float fogfactor;"
       
       "void main() {"
   //      "vec3 eyeNormal = normalize(normalMatrix * normal);"
@@ -248,7 +296,9 @@ void init() {
                        
   //      "vColor = diffuseColor * nDotVP;"
         + texture_only("vTexCoord = gl_MultiTexCoord0.xy;") +
-        "vColor = gl_Color;"
+        + ((f & GF_LIGHTFOG) ? 
+            "vColor = gl_Color * clamp(1.0 + gl_Vertex.z * fogfactor, 0.0, 1.0);"
+          : "vColor = gl_Color;") +
           
         "gl_Position = modelViewProjectionMatrix * gl_Vertex;"
         "}",
@@ -263,9 +313,6 @@ void init() {
       );
     }
   
-  programs[2] = programs[0];
-  programs[3] = programs[1];
-
   glEnableClientState(GL_VERTEX_ARRAY);
   switch_mode(gmColored);
   programs[gmColored]->enable();
@@ -300,6 +347,11 @@ void color2(int color) {
   glColor4f(c[3] / 255.0, c[2] / 255.0, c[1]/255.0, c[0] / 255.0);
   }
 
+void color2(int color, ld part) {
+  unsigned char *c = (unsigned char*) (&color);
+  glColor4f(c[3] / 255.0 * part, c[2] / 255.0 * part, c[1]/255.0 * part, c[0] / 255.0);
+  }
+
 void colorClear(int color) {
   unsigned char *c = (unsigned char*) (&color);
   glClearColor(c[3] / 255.0, c[2] / 255.0, c[1]/255.0, c[0] / 255.0);
@@ -328,6 +380,7 @@ void switch_mode(eMode m) {
   if(oldflags & GF_VARCOLOR)
     glDisableClientState(GL_COLOR_ARRAY);
   if(newflags & GF_LIGHTFOG) {
+#if !CAP_SHADER    
     GLfloat light_ambient[] = { 3.5, 3.5, 3.5, 1.0 };
     GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
     GLfloat light_position[] = { 0.0, 0.0, 0.0, 1.0 };
@@ -345,16 +398,23 @@ void switch_mode(eMode m) {
     glEnable(GL_FOG);
     glFogi(GL_FOG_MODE, GL_LINEAR);
     glFogf(GL_FOG_START, 0);
+#endif
     }
   if(oldflags & GF_LIGHTFOG) {
+#if !CAP_SHADER
     glDisable(GL_FOG);
     glDisable(GL_LIGHTING);
+#endif
     }
   mode = m;
   }
 
 void fog_max(ld fogmax) {
+  #if CAP_SHADER
+  glUniform1f(current->uniforms[UNIFORM_FOGFACTOR], 1 / fogmax);
+  #else
   glFogf(GL_FOG_END, fogmax);
+  #endif
   }
 
 }