drawing sprite back to front

src/engine/object/ObjectGl.java

@@ -6,6 +6,8 @@ import engine.graphics.Shader;
 import engine.math.Matrix4f;
 import engine.math.Vector3f;
 
+import java.util.Comparator;
+
 /**
  *
  */
@@ -18,6 +20,8 @@ public class ObjectGl {
     public static Matrix4f projection;
     public static Matrix4f view;
 
+    public float zPos;
+
     public ObjectGl(){
 
     }
@@ -26,6 +30,7 @@ public class ObjectGl {
         this.vertexArray = new VertexArray(Primitive.createRectangle(x, y, z, h, w), Primitive.rectangle_indices, null, null);
         this.transform = Matrix4f.identity();
         this.shader = new Shader("shaders/ObjectGl/vert.glsl","shaders/ObjectGl/frag.glsl");
+        this.zPos = z;
     }
 
     public void resetTransform(){
@@ -34,6 +39,7 @@ public class ObjectGl {
 
     public void translate(Vector3f vec){
         this.transform = this.transform.multiply(Matrix4f.translate(vec));
+        this.zPos += vec.z;
     }
 
     public void scale(Vector3f vec){

src/engine/object/ObjectGlColor.java

@@ -11,5 +11,6 @@ public class ObjectGlColor extends ObjectGl{
         this.vertexArray = new VertexArray(Primitive.createRectangle(x, y, z, h, w), Primitive.rectangle_indices, color, null);
         this.transform = Matrix4f.identity();
         this.shader = new Shader("shaders/ObjectGlColor/vert.glsl","shaders/ObjectGlColor/frag.glsl");
+        this.zPos = z;
     }
 }

src/engine/object/ObjectGlTex.java

@@ -22,6 +22,7 @@ public class ObjectGlTex extends ObjectGl{
         this.vertexArray = new VertexArray(Primitive.createRectangle(x, y, z, h, w), Primitive.rectangle_indices, null, texCoord);
         this.transform = Matrix4f.identity();
         this.shader = new Shader("shaders/ObjectGlTex/vert.glsl","shaders/ObjectGlTex/frag.glsl");
+        this.zPos = z;
 
         this.textures = new ArrayList<>();
         int count = 0;

src/engine/object/ObjectGlTexColor.java

@@ -16,6 +16,7 @@ public class ObjectGlTexColor extends ObjectGlTex{
         this.vertexArray = new VertexArray(Primitive.createRectangle(x, y, z, h, w), Primitive.rectangle_indices, color, texCoord);
         this.transform = Matrix4f.identity();
         this.shader = new Shader("shaders/ObjectGlTexColor/vert.glsl","shaders/ObjectGlTexColor/frag.glsl");
+        this.zPos = z;
 
         this.textures = new ArrayList<>();
         int count = 0;

src/engine/object/SortZ.java

@@ -0,0 +1,11 @@
+package engine.object;
+
+import java.util.Comparator;
+
+public class SortZ implements Comparator<ObjectGl>
+{
+    public int compare(ObjectGl a, ObjectGl b)
+    {
+        return (int) (a.zPos - b.zPos);
+    }
+}