Use preprocessor macros in shader

Increases FPS from 300 to 340

2 files changed, 63 insertions, 3 deletions

diff --git a/src/main/java/makamys/neodymium/renderer/NeoRenderer.java b/src/main/java/makamys/neodymium/renderer/NeoRenderer.java
index 172ddcd..d307c28 100644
--- a/src/main/java/makamys/neodymium/renderer/NeoRenderer.java
+++ b/src/main/java/makamys/neodymium/renderer/NeoRenderer.java
@@ -14,10 +14,12 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Queue;
+import java.util.Set;
 import java.util.concurrent.ConcurrentLinkedQueue;
 
 import org.lwjgl.BufferUtils;
@@ -30,6 +32,7 @@ import makamys.neodymium.Neodymium;
 import makamys.neodymium.ducks.IWorldRenderer;
 import makamys.neodymium.renderer.Mesh.GPUStatus;
 import makamys.neodymium.util.GuiHelper;
+import makamys.neodymium.util.Preprocessor;
 import makamys.neodymium.util.Util;
 import net.minecraft.block.Block;
 import net.minecraft.block.material.Material;
@@ -464,12 +467,20 @@ public class NeoRenderer {
     }
     
        public void reloadShader() {
-            boolean errors = false;
+           Set<String> defines = new HashSet<>();
+           if(Config.renderFog) {
+               defines.add("RENDER_FOG");
+           }
+           if(Config.simplifyChunkMeshes) {
+               defines.add("SIMPLIFY_MESHES");
+           }
            
+            boolean errors = false;
+            
             int vertexShader;
             vertexShader = glCreateShader(GL_VERTEX_SHADER);
             
-            glShaderSource(vertexShader, Util.readFile("shaders/chunk.vert"));
+            glShaderSource(vertexShader, Preprocessor.preprocess(Util.readFile("shaders/chunk.vert"), defines));
             glCompileShader(vertexShader);
             
             if(glGetShaderi(vertexShader, GL_COMPILE_STATUS) == 0) {
@@ -480,7 +491,7 @@ public class NeoRenderer {
             int fragmentShader;
             fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
             
-            glShaderSource(fragmentShader, Util.readFile("shaders/chunk.frag"));
+            glShaderSource(fragmentShader, Preprocessor.preprocess(Util.readFile("shaders/chunk.frag"), defines));
             glCompileShader(fragmentShader);
             
             if(glGetShaderi(fragmentShader, GL_COMPILE_STATUS) == 0) {
diff --git a/src/main/java/makamys/neodymium/util/Preprocessor.java b/src/main/java/makamys/neodymium/util/Preprocessor.java
new file mode 100644
index 0000000..8ee9229
--- /dev/null
+++ b/src/main/java/makamys/neodymium/util/Preprocessor.java
@@ -0,0 +1,49 @@
+package makamys.neodymium.util;
+
+import java.util.Set;
+
+public class Preprocessor {
+    
+    public static String preprocess(String text, Set<String> defines) {
+        String[] lines = text.replaceAll("\\r\\n", "\\n").split("\\n");
+        
+        IfElseBlockStatus ifElseBlockStatus = IfElseBlockStatus.NONE;
+        boolean ifElseConditionMet = false;
+        
+        for(int i = 0; i < lines.length; i++) {
+            String line = lines[i];
+            
+            boolean commentLine = false;
+            
+            if(line.startsWith("#ifdef ")) {
+                ifElseBlockStatus = IfElseBlockStatus.IF;
+                ifElseConditionMet = defines.contains(line.split(" ")[1]);
+                commentLine = true;
+            } else if(line.startsWith("#else")) {
+                ifElseBlockStatus = IfElseBlockStatus.ELSE;
+                commentLine = true;
+            } else if(line.startsWith("#endif")) {
+                ifElseBlockStatus = IfElseBlockStatus.NONE;
+                commentLine = true;
+            } else {
+                if(ifElseBlockStatus == IfElseBlockStatus.IF && !ifElseConditionMet) {
+                    commentLine = true;
+                }
+                if(ifElseBlockStatus == IfElseBlockStatus.ELSE && ifElseConditionMet) {
+                    commentLine = true;
+                }
+            }
+            
+            if(commentLine) {
+                lines[i] = "//" + line;
+            }
+        }
+        
+        return String.join("\n", lines);
+    }
+    
+    public static enum IfElseBlockStatus {
+        NONE, IF, ELSE;
+    }
+    
+}