From 0412ea7b7c32f7f3e06f8336890227f7072fe44e Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Tue, 20 Feb 2018 11:30:39 +0100
Subject: [PATCH] glhr::id is now a constant; streamlined applymatrix

---
 basegraph.cpp | 12 +++++++++++-
 graph.cpp     |  2 +-
 polygons.cpp  | 15 +++++----------
 rug.cpp       |  2 +-
 shaders.cpp   | 21 ++++++++++++---------
 5 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/basegraph.cpp b/basegraph.cpp
index c90a8b7c..6e4c70ad 100644
--- a/basegraph.cpp
+++ b/basegraph.cpp
@@ -218,6 +218,16 @@ void stereo::set_projection(int ed) {
     stereo::scrdist_text = 0;
     }
   else {
+
+    if(hyperbolic && vid.alpha > -1) {
+      // Because of the transformation from H3 to the Minkowski hyperboloid,
+      // points with negative Z can be generated in some 3D settings.
+      // This happens for points below the camera, but above the plane.
+      // These points should still be viewed, though, so we disable the
+      // depth clipping
+      glhr::projection_multiply(glhr::scale(1,1,0));
+      }
+
     glhr::projection_multiply(glhr::frustum(vid.xres * 1. / vid.yres, 1));
 
     GLfloat sc = vid.radius / (vid.yres/2.);
@@ -893,7 +903,7 @@ void drawCircle(int x, int y, int size, int color) {
   #if CAP_GL
   if(vid.usingGL) {
     glhr::be_nontextured();
-    glhr::set_modelview(glhr::id());
+    glhr::id_modelview();
     glcoords.clear();
     glhr::color2(color);
     x -= vid.xcenter; y -= vid.ycenter;
diff --git a/graph.cpp b/graph.cpp
index 222697c2..0dd08a45 100644
--- a/graph.cpp
+++ b/graph.cpp
@@ -2307,7 +2307,7 @@ void drawaura() {
       }
     }
   glhr::switch_mode(glhr::gmVarColored);
-  glhr::set_modelview(glhr::id());
+  glhr::id_modelview();
   glhr::prepare(auravertices);
   glDrawArrays(GL_TRIANGLES, 0, size(auravertices));    
 
diff --git a/polygons.cpp b/polygons.cpp
index 85bdd431..4a518670 100644
--- a/polygons.cpp
+++ b/polygons.cpp
@@ -232,16 +232,11 @@ void glapplymatrix(const transmatrix& V) {
     for(int x=0; x<3; x++) mat[id++] = V[x][y];
     mat[id++] = 0;
     }
-  {for(int x=0; x<3; x++) mat[id++] = 0;} mat[id++] = 1;
-  
+  mat[12] = 0;
+  mat[13] = 0;
   mat[14] = GLfloat(vid.alpha);
+  mat[15] = 1;  
 
-  if(mat[10] + vid.alpha < 0 && !sphere && !euclid) {
-    for(int i=0; i<3; i++)
-    for(int j=0; j<16; j+=4)
-      mat[j+i] = -mat[j+i];
-    }
-  
   glhr::set_modelview(glhr::as_glmatrix(mat));
   }
 
@@ -259,7 +254,7 @@ void setmatrix(int useV, const transmatrix& V) {
     glhr::set_modelview(glhr::as_glmatrix(mat));
     }
   else
-    glhr::set_modelview(glhr::id());
+    glhr::id_modelview();
   }
   
 void gldraw(int useV, const transmatrix& V, const vector<glvertex>& v, int ps, int pq, int col, int outline, int flags, textureinfo *tinf) {
@@ -304,7 +299,7 @@ void gldraw(int useV, const transmatrix& V, const vector<glvertex>& v, int ps, i
           make_array<GLfloat>(-xx, +yy, stereo::scrdist)
           };
         glhr::vertices(scr);
-        glhr::set_modelview(glhr::id());
+        glhr::id_modelview();
         glDrawArrays(tinf ? GL_TRIANGLES : GL_TRIANGLE_FAN, 0, 4);
         glhr::vertices(v);
         setmatrix(useV, V);
diff --git a/rug.cpp b/rug.cpp
index 525df032..558f7a53 100644
--- a/rug.cpp
+++ b/rug.cpp
@@ -1179,7 +1179,7 @@ void drawRugScene() {
     for(int t=0; t<size(triangles); t++)
       drawTriangle(triangles[t]);
       
-    glhr::set_modelview(glhr::id());
+    glhr::id_modelview();
     glhr::prepare(ct_array);
     glDrawArrays(GL_TRIANGLES, 0, size(ct_array));
 
diff --git a/shaders.cpp b/shaders.cpp
index ceb1586f..012d3cd2 100644
--- a/shaders.cpp
+++ b/shaders.cpp
@@ -73,13 +73,7 @@ glmatrix operator * (glmatrix m1, glmatrix m2) {
   return res;
   }
 
-glmatrix id() {
-  glmatrix M;
-  for(int i=0; i<4; i++)
-  for(int j=0; j<4; j++)
-    M[i][j] = (i == j);
-  return M;
-  }
+glmatrix id = {{{1,0,0,0}, {0,1,0,0}, {0,0,1,0}, {0,0,0,1}}};
 
 glmatrix scale(ld x, ld y, ld z) {
   glmatrix tmp;
@@ -141,6 +135,11 @@ void set_modelview(const glmatrix& m) {
   glLoadMatrixf(m.as_array());
   }
 
+void id_modelview() {
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity();
+  }
+
 #endif
 
 // /* shaders */
@@ -150,7 +149,7 @@ void set_modelview(const glmatrix& m) {
 glmatrix projection;
 
 void new_projection() {
-  projection = id();
+  projection = id;
   }
 
 void projection_multiply(const glmatrix& m) {
@@ -304,6 +303,10 @@ void set_modelview(const glmatrix& modelview) {
   // glUniformMatrix3fv(current->uniforms[UNIFORM_NORMAL_MATRIX], 1, 0, nm[0]);
   }
 
+void id_modelview() {
+  glUniformMatrix4fv(current->uMVP, 1, 0, projection.as_array());
+  }
+
 #endif
 
 void color2(int color, ld part = 1) {
@@ -436,7 +439,7 @@ void init() {
   #endif
   
   #if CAP_SHADER
-  projection = id();
+  projection = id;
       
   for(int i=0; i<4; i++) {
     flagtype f = flags[i];