finally nailed the lighting equation, it's now truly mathematically equivalent to opengl 1.3

build.gradle

@@ -37,11 +37,11 @@ dependencies {
 teavm {
    
    compileScopes = null;
-   minifying = false;
+   minifying = true;
    maxTopLevelNames = 10000;
    properties = null;
    debugInformationGenerated = false;
-   sourceMapsGenerated = false;
+   sourceMapsGenerated = true;
    sourceFilesCopied = false;
    incremental = false;
    transformers = null;

lwjgl-rundir/resources/glsl/core.glsl

@@ -11,7 +11,6 @@ precision highp float;
 
 uniform mat4 matrix_m;
 uniform mat4 matrix_p;
-uniform mat3 matrix_mn;
 uniform mat4 matrix_t;
 
 #ifdef CC_VERT
@@ -84,7 +83,6 @@ uniform vec2 texCoordV1;
 #ifdef CC_lighting
 uniform vec3 light0Pos;
 uniform vec3 light1Pos;
-uniform vec3 invertNormals;
 uniform vec3 normalUniform;
 #endif
 #ifdef CC_fog
@@ -214,7 +212,7 @@ void main(){
 #else
 	vec3 normal = normalUniform;
 #endif
-	normal = normalize(matrix_mn * normal);
+	normal = normalize(mat3(matrix_m) * normal);
 	float ins = max(dot(normal, -light0Pos), 0.0) + max(dot(normal, -light1Pos), 0.0);
 	color.rgb *= min((0.4 + ins * 0.6), 1.0);
 #endif

src/main/java/net/lax1dude/eaglercraft/glemu/EaglerAdapterGL30.java

@@ -13,6 +13,7 @@ import net.lax1dude.eaglercraft.glemu.vector.Matrix3f;
 import net.lax1dude.eaglercraft.glemu.vector.Matrix4f;
 import net.lax1dude.eaglercraft.glemu.vector.Vector3f;
 import net.lax1dude.eaglercraft.glemu.vector.Vector4f;
+import net.minecraft.src.RenderItem;
 
 public class EaglerAdapterGL30 extends EaglerAdapterImpl2 {
 
@@ -217,8 +218,6 @@ public class EaglerAdapterGL30 extends EaglerAdapterImpl2 {
 	private static int matrixMode = GL_MODELVIEW;
 
 	static Matrix4f[] matModelV = new Matrix4f[32];
-	static Matrix4f matNormV = new Matrix4f();
-	static Matrix3f matNormV3 = new Matrix3f();
 	static int matModelPointer = 0;
 	
 	static Matrix4f[] matProjV = new Matrix4f[6];
@@ -494,13 +493,18 @@ public class EaglerAdapterGL30 extends EaglerAdapterImpl2 {
 		lightPos1vec.set(-0.2f, 1.0f, 0.7f, 0.0f); lightPos1vec.normalise();
 		Matrix4f.transform(matModelV[matModelPointer], lightPos0vec, lightPos0vec).normalise();
 		Matrix4f.transform(matModelV[matModelPointer], lightPos1vec, lightPos1vec).normalise();
-		
+		if(RenderItem.isRenderInProgress) {
+			System.out.println(""+lightPos0vec+"  "+lightPos1vec);
+			Thread.dumpStack();
+		}
 	}
 	public static final void flipLightMatrix() {
-		lightPos0vec0.set(lightPos0vec);
-		lightPos1vec0.set(lightPos1vec);
+		lightPos0vec.x = -lightPos0vec.x;
+		lightPos1vec.x = -lightPos1vec.x;
 		lightPos0vec.y = -lightPos0vec.y;
 		lightPos1vec.y = -lightPos1vec.y;
+		lightPos0vec.z = -lightPos0vec.z;
+		lightPos1vec.z = -lightPos1vec.z;
 	}
 	public static final void revertLightMatrix() {
 		lightPos0vec.set(lightPos0vec0);
@@ -979,13 +983,6 @@ public class EaglerAdapterGL30 extends EaglerAdapterImpl2 {
 		s.setTextureMatrix(matTexV[matTexPointer]);
 		if(enableColorMaterial && enableLighting) {
 			s.setNormal(normalX, normalY, normalZ);
-			Matrix4f matNormV_l = matNormV;
-			Matrix3f matNormV3_l = matNormV3;
-			matNormV_l.load(matModelV[matModelPointer]).invert().transpose();
-			matNormV3_l.m00 = matNormV_l.m00; matNormV3_l.m01 = matNormV_l.m01; matNormV3_l.m02 = matNormV_l.m02;
-			matNormV3_l.m10 = matNormV_l.m10; matNormV3_l.m11 = matNormV_l.m11; matNormV3_l.m12 = matNormV_l.m12;
-			matNormV3_l.m20 = matNormV_l.m20; matNormV3_l.m21 = matNormV_l.m21; matNormV3_l.m22 = matNormV_l.m22;
-			s.setModelNormalMatrix(matNormV3_l);
 			s.setLightPositions(lightPos0vec, lightPos1vec);
 		}
 		s.setTex0Coords(tex0X, tex0Y);

src/main/java/net/lax1dude/eaglercraft/glemu/FixedFunctionShader.java

@@ -1,10 +1,8 @@
 package net.lax1dude.eaglercraft.glemu;
 
 import net.lax1dude.eaglercraft.EaglerAdapter;
-import net.lax1dude.eaglercraft.glemu.vector.Matrix3f;
 import net.lax1dude.eaglercraft.glemu.vector.Matrix4f;
 import net.lax1dude.eaglercraft.glemu.vector.Vector2f;
-import net.lax1dude.eaglercraft.glemu.vector.Vector3f;
 import net.lax1dude.eaglercraft.glemu.vector.Vector4f;
 
 import static net.lax1dude.eaglercraft.glemu.EaglerAdapterGL30.*;
@@ -105,7 +103,6 @@ public class FixedFunctionShader {
 
 	private UniformGL u_matrix_m = null;
 	private UniformGL u_matrix_p = null;
-	private UniformGL u_matrix_mn = null;
 	private UniformGL u_matrix_t = null;
 	
 	private UniformGL u_fogColor = null;
@@ -218,7 +215,6 @@ public class FixedFunctionShader {
 		_wglUseProgram(globject);
 
 		u_matrix_m = _wglGetUniformLocation(globject, "matrix_m");
-		u_matrix_mn = _wglGetUniformLocation(globject, "matrix_mn");
 		u_matrix_p = _wglGetUniformLocation(globject, "matrix_p");
 		u_matrix_t = _wglGetUniformLocation(globject, "matrix_t");
 
@@ -338,34 +334,15 @@ public class FixedFunctionShader {
 	private float[] modelBuffer = new float[16];
 	private float[] projectionBuffer = new float[16];
 	private float[] textureBuffer = new float[16];
-	private float[] normalModelBuffer = new float[9];
 
 	private Matrix4f modelMatrix = (Matrix4f) new Matrix4f().setZero();
 	private Matrix4f projectionMatrix = (Matrix4f) new Matrix4f().setZero();
 	private Matrix4f textureMatrix = (Matrix4f) new Matrix4f().setZero();
-	private Matrix3f normalModelMatrix = (Matrix3f) new Matrix3f().setZero();
 	private Matrix4f inverseModelMatrix = (Matrix4f) new Matrix4f().setZero();
 	private Vector4f light0Pos = new Vector4f();
 	private Vector4f light1Pos = new Vector4f();
 	private Vector2f anisotropicFix = new Vector2f(0.0f, 0.0f);
 	
-	private boolean bound = false;
-
-	private float invertNormalsX = 0.0f;
-	private float invertNormalsY = 0.0f;
-	private float invertNormalsZ = 0.0f;
-	
-	public void setInvertNormals(float x, float y, float z) {
-		/*
-		if(invertNormalsX != x || invertNormalsY != y || invertNormalsZ != z) {
-			invertNormalsX = x;
-			invertNormalsY = y;
-			invertNormalsZ = z;
-			_wglUniform3f(u_invertNormals, x, y, z);
-		}
-		*/
-	}
-	
 	public void setAnisotropicFix(float x, float y) {
 		if(anisotropicFix.x != x || anisotropicFix.y != y) {
 			anisotropicFix.x = x;
@@ -385,12 +362,6 @@ public class FixedFunctionShader {
 			}
 		}
 	}
-	public void setModelNormalMatrix(Matrix3f mat) {
-		if(!mat.equals(normalModelMatrix)) {
-			normalModelMatrix.load(mat).store(normalModelBuffer);
-			_wglUniformMat3fv(u_matrix_mn, normalModelBuffer);
-		}
-	}
 	public void setProjectionMatrix(Matrix4f mat) {
 		if(!mat.equals(projectionMatrix)) {
 			projectionMatrix.load(mat).store(projectionBuffer);

src/main/java/net/minecraft/src/ItemRenderer.java

@@ -67,7 +67,7 @@ public class ItemRenderer {
 			float var9 = var4.getMaxV();
 			float var10 = 0.0F;
 			float var11 = 0.3F;
-			RenderHelper.enableStandardItemLighting2();
+			EaglerAdapter.flipLightMatrix();
 			EaglerAdapter.glEnable(EaglerAdapter.GL_RESCALE_NORMAL);
 			EaglerAdapter.glTranslatef(-var10, -var11, 0.0F);
 			float var12 = 1.5F;
@@ -108,9 +108,10 @@ public class ItemRenderer {
 			}
 
 			EaglerAdapter.glDisable(EaglerAdapter.GL_RESCALE_NORMAL);
-			EaglerAdapter.revertLightMatrix();
 		}
 		
+		EaglerAdapter.flipLightMatrix();
+
 		EaglerAdapter.glPopMatrix();
 	}
 

src/main/java/net/minecraft/src/RenderItem.java

@@ -25,10 +25,13 @@ public class RenderItem extends Render {
 	private static final TextureLocation terrain = new TextureLocation("/terrain.png");
 	private static final TextureLocation items = new TextureLocation("/gui/items.png");
 	
+	public static boolean isRenderInProgress = false;
+
 	/**
 	 * Renders the item
 	 */
 	public void doRenderItem(EntityItem par1EntityItem, double par2, double par4, double par6, float par8, float par9) {
+		isRenderInProgress = true;
 		this.random.setSeed(187L);
 		ItemStack var10 = par1EntityItem.getEntityItem();
 		
@@ -56,6 +59,7 @@ public class RenderItem extends Render {
 
 			EaglerAdapter.glTranslatef((float) par2, (float) par4 + var11, (float) par6);
 			EaglerAdapter.glEnable(EaglerAdapter.GL_RESCALE_NORMAL);
+			
 			int var17;
 			float var18;
 			float var19;
@@ -64,6 +68,7 @@ public class RenderItem extends Render {
 			if (var10.getItemSpriteNumber() == 0 && Block.blocksList[var10.itemID] != null && RenderBlocks.renderItemIn3d(Block.blocksList[var10.itemID].getRenderType())) {
 				Block var22 = Block.blocksList[var10.itemID];
 				EaglerAdapter.glRotatef(var12, 0.0F, 1.0F, 0.0F);
+				//RenderHelper.enableStandardItemLighting();
 
 				if (renderInFrame) {
 					EaglerAdapter.glScalef(1.25F, 1.25F, 1.25F);
@@ -158,6 +163,7 @@ public class RenderItem extends Render {
 			EaglerAdapter.glDisable(EaglerAdapter.GL_RESCALE_NORMAL);
 			EaglerAdapter.glPopMatrix();
 		}
+		isRenderInProgress = false;
 	}
 	
 	private static final TextureLocation glint = new TextureLocation("%blur%/misc/glint.png");