From 8a92660d6e903427ed12637e829808583743cd85 Mon Sep 17 00:00:00 2001
From: Tyler <tylermw@gmail.com>
Date: Sun, 20 May 2018 21:47:53 -0400
Subject: [PATCH] - Fixed out of bounds memory issue - Propogated remove_edges
 argument to Lambert term in rayshade

---
 R/lambshade.R     |  6 ++++--
 R/rayshade.R      |  4 ++--
 src/lambshade.cpp | 16 ++++++++++++----
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/R/lambshade.R b/R/lambshade.R
index ac8232b2..b8d8c744 100644
--- a/R/lambshade.R
+++ b/R/lambshade.R
@@ -28,7 +28,9 @@ lambshade = function(heightmap, rayangle, sunangle, zscale = 1, zero_negative =
     shadowmatrix[shadowmatrix < 0] = 0
   }
   if(remove_edges) {
-    shadowmatrix = shadowmatrix[c(-1,-nrow(shadowmatrix)),c(-1,-ncol(shadowmatrix))]
+    shadowmatrixremove = shadowmatrix[c(-1,-nrow(shadowmatrix)),c(-1,-ncol(shadowmatrix))]
+    return(shadowmatrixremove)
+  } else {
+    return(shadowmatrix)
   }
-  return(shadowmatrix)
 }
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diff --git a/R/rayshade.R b/R/rayshade.R
index 0c2c6e9f..6e3bad93 100644
--- a/R/rayshade.R
+++ b/R/rayshade.R
@@ -51,7 +51,7 @@ rayshade = function(heightmap, anglebreaks, sunangle, maxsearch, lambert=TRUE, z
     shadowmatrix[shadowmatrix<0] = 0
     if(lambert) {
       shadowmatrix = shadowmatrix * lambshade(heightmap, rayangle = mean(anglebreaks), 
-                                              sunangle = sunangle, zscale = zscale)
+                                              sunangle = sunangle, zscale = zscale, remove_edges=remove_edges)
     }
     return(shadowmatrix)
   } else {
@@ -79,7 +79,7 @@ rayshade = function(heightmap, anglebreaks, sunangle, maxsearch, lambert=TRUE, z
     }
     if(lambert) {
       shadowmatrix = shadowmatrix * lambshade(heightmap, rayangle = mean(anglebreaks), 
-                                              sunangle = sunangle, zscale = zscale)
+                                              sunangle = sunangle, zscale = zscale, remove_edges=remove_edges)
     }
     return(shadowmatrix)
   }
diff --git a/src/lambshade.cpp b/src/lambshade.cpp
index 4ea7f273..86164cab 100644
--- a/src/lambshade.cpp
+++ b/src/lambshade.cpp
@@ -11,7 +11,7 @@ NumericVector vcrossnorm(NumericVector a, NumericVector b) {
   return(result);
 }
 
-double dot_product(NumericVector x, NumericVector y) {
+double dot_product(const NumericVector x, const NumericVector y) {
   return std::inner_product(x.begin(), x.end(), y.begin(), 0.0);
 }
 
@@ -26,7 +26,7 @@ NumericMatrix lambshade_cpp(NumericMatrix heightmap, NumericVector rayvector) {
   NumericVector tempvector4 = NumericVector::create(0,-1,0);
   for(int col = 0; col < heightmap.ncol(); col++) {
     for(int row = 0; row < heightmap.nrow(); row++) {
-      if(row != 0 || col != 0 || row != heightmap.nrow() - 1 || col != heightmap.ncol() - 1) {
+      if(row != 0 && col != 0 && row < heightmap.nrow() - 1 && col < heightmap.ncol() - 1) {
         tempvector1(2) = heightmap(row,col)-heightmap(row,col+1);
         tempvector2(2) = heightmap(row,col)-heightmap(row+1,col);
         tempvector3(2) = heightmap(row,col)-heightmap(row,col-1);
@@ -35,11 +35,12 @@ NumericMatrix lambshade_cpp(NumericMatrix heightmap, NumericVector rayvector) {
         storevector2 = vcrossnorm(tempvector3,tempvector4);
         shaded_matrix(row,col) = dot_product((storevector1 + storevector2)/2, rayvector);
       } else {
-        if(row == 0 || col == 0) {
+        if((row == 0 || col == 0) && (row != heightmap.nrow() - 1 || col != heightmap.ncol() - 1)) {
           tempvector1(2) = heightmap(row,col)-heightmap(row,col+1);
           tempvector2(2) = heightmap(row,col)-heightmap(row+1,col);
           shaded_matrix(row,col) = dot_product(vcrossnorm(tempvector1,tempvector2), rayvector);
-        } else {
+        } 
+        if((row != 0 || col != 0) && (row == heightmap.nrow() - 1 || col == heightmap.ncol() - 1)) {
           tempvector3(2) = heightmap(row,col)-heightmap(row,col-1);
           tempvector4(2) = heightmap(row,col)-heightmap(row-1,col);
           shaded_matrix(row,col) = dot_product(vcrossnorm(tempvector3,tempvector4), rayvector);
@@ -47,5 +48,12 @@ NumericMatrix lambshade_cpp(NumericMatrix heightmap, NumericVector rayvector) {
       }
     }
   }
+  tempvector2(2) = heightmap(0,heightmap.ncol())-heightmap(1,heightmap.ncol());
+  tempvector3(2) = heightmap(0,heightmap.ncol())-heightmap(0,heightmap.ncol()-1);
+  shaded_matrix(0,heightmap.ncol()-1) = dot_product(vcrossnorm(tempvector3,tempvector2), rayvector);
+  tempvector1(2) = heightmap(heightmap.nrow(),0)-heightmap(heightmap.nrow(),1);
+  tempvector4(2) = heightmap(heightmap.nrow(),0)-heightmap(heightmap.nrow()-1,0);
+  shaded_matrix(heightmap.nrow()-1,0) = dot_product(vcrossnorm(tempvector4,tempvector1), rayvector);
+  
   return(shaded_matrix);
 }
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