From 2e0cf7fe53915f4d760c3b90953d95b57a3288a4 Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Fri, 27 Dec 2019 00:49:58 +0100
Subject: [PATCH] band_shift correctly applied in shader-based band model

---
 basegraph.cpp | 5 ++++-
 shaders.cpp   | 3 +++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/basegraph.cpp b/basegraph.cpp
index 34a1f47f..e8c47bc8 100644
--- a/basegraph.cpp
+++ b/basegraph.cpp
@@ -236,11 +236,14 @@ EX bool new_projection_needed;
 inline void reset_projection() { new_projection_needed = true; }
 #endif
 
+EX ld lband_shift;
+
 void display_data::set_all(int ed) {
   auto t = this;
   auto current_projection = tie(ed, pmodel, t, current_rbuffer);
-  if(new_projection_needed || !glhr::current_glprogram || (next_shader_flags & GF_which) != (glhr::current_glprogram->shader_flags & GF_which) || current_projection != last_projection) {
+  if(new_projection_needed || !glhr::current_glprogram || (next_shader_flags & GF_which) != (glhr::current_glprogram->shader_flags & GF_which) || current_projection != last_projection || band_shift != lband_shift) {
     last_projection = current_projection;
+    lband_shift = band_shift;
     set_projection(ed);
     set_mask(ed);
     set_viewport(ed);
diff --git a/shaders.cpp b/shaders.cpp
index f47475b6..e6d88181 100644
--- a/shaders.cpp
+++ b/shaders.cpp
@@ -439,6 +439,9 @@ void display_data::set_projection(int ed) {
   if(selected->shader_flags & SF_BAND)
     glhr::projection_multiply(glhr::scale(2 / M_PI, 2 / M_PI, GDIM == 3 ? 2/M_PI : 1));
 
+  if(selected->shader_flags & SF_BAND)
+    glhr::projection_multiply(glhr::translate(band_shift, 0, 0));
+
   if(selected->shader_flags & SF_HALFPLANE) {
     glhr::projection_multiply(glhr::translate(0, 1, 0));      
     glhr::projection_multiply(glhr::scale(-1, 1, 1));