From a59dc8be58ac45b5edc7781549d926acd7f7a9ba Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Mon, 16 Sep 2019 10:38:42 +0200
Subject: [PATCH] fixed binocular vision (isotropic only for now)

---
 basegraph.cpp | 12 +++++++++---
 shaders.cpp   | 13 ++++++++++++-
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/basegraph.cpp b/basegraph.cpp
index 8d8ef557..f44711a6 100644
--- a/basegraph.cpp
+++ b/basegraph.cpp
@@ -246,6 +246,7 @@ EX void start_projection(int ed, bool perspective) {
   }
 
 EX void eyewidth_translate(int ed) {
+  glhr::using_eyeshift = false;
   if(ed) glhr::projection_multiply(glhr::translate(-ed * current_display->eyewidth(), 0, 0));
   }
 
@@ -439,11 +440,16 @@ void display_data::set_projection(int ed) {
       GLfloat sc = current_display->radius / (cd->ysize/2.);  
       glhr::projection_multiply(glhr::scale(sc, -sc, -1));
       }
-
     
     if(ed) {
-      if(pers3)
-        glhr::projection_multiply(glhr::tmtogl(xpush(vid.ipd * ed/2)));
+      if(pers3) {
+        if(anyshiftclick)
+          glhr::projection_multiply(glhr::tmtogl(xpush(vid.ipd * ed/2)));
+        else {
+          glhr::using_eyeshift = true;
+          glhr::eyeshift = glhr::tmtogl(xpush(vid.ipd * ed/2));
+          }
+        }
       else
         glhr::projection_multiply(glhr::translate(vid.ipd * ed/2, 0, 0));
       }  
diff --git a/shaders.cpp b/shaders.cpp
index ae155606..2c69b66a 100644
--- a/shaders.cpp
+++ b/shaders.cpp
@@ -436,6 +436,9 @@ bool operator != (const glmatrix& m1, const glmatrix& m2) {
 
 bool uses_mvp(shader_projection sp) { return among(sp, shader_projection::standard, shader_projection::flatten); }
 
+EX glmatrix eyeshift;
+EX bool using_eyeshift;
+
 EX void set_modelview(const glmatrix& modelview) {
   #if CAP_NOSHADER
   if(noshaders) {
@@ -446,7 +449,15 @@ EX void set_modelview(const glmatrix& modelview) {
   #endif
   if(!current) return;
   if(!uses_mvp(current_shader_projection)) {
-    if(modelview != current_modelview) {
+    if(using_eyeshift) {
+      glmatrix mvp = modelview * eyeshift;
+      #if MINIMIZE_GL_CALLS
+      if(mvp == current_matrix) return;
+      current_matrix = mvp;
+      #endif
+      glUniformMatrix4fv(current->uMV, 1, 0, mvp.as_array());
+      }
+    else if(modelview != current_modelview) {
       current_modelview = modelview;
       glUniformMatrix4fv(current->uMV, 1, 0, modelview.as_array());
       }