Use texture alignment to reduce artifacts

Vocaluxe/Lib/Draw/CDirect3D.cs

@@ -430,6 +430,12 @@ namespace Vocaluxe.Lib.Draw
         /// <param name="isReflection">If true, then color is faded out in y direction</param>
         private void _DrawTexture(CD3DTexture texture, SDrawCoords dc, SColorF color, bool isReflection = false)
         {
+            //Align the pixels because Direct3D expects the pixels to be the left top corner
+            dc.Wx1 -= 0.5f;
+            dc.Wy1 -= 0.5f;
+            dc.Wx2 -= 0.5f;
+            dc.Wy2 -= 0.5f;
+
             color.A *= CGraphics.GlobalAlpha;
             int c = color.AsColor().ToArgb();
             int c2;
@@ -446,7 +452,7 @@ namespace Vocaluxe.Lib.Draw
             vert[1] = new STexturedColoredVertex(new Vector3(dc.Wx1, -dc.Wy2, dc.Wz), new Vector2(dc.Tx1, dc.Ty2), c2);
             vert[2] = new STexturedColoredVertex(new Vector3(dc.Wx2, -dc.Wy2, dc.Wz), new Vector2(dc.Tx2, dc.Ty2), c2);
             vert[3] = new STexturedColoredVertex(new Vector3(dc.Wx2, -dc.Wy1, dc.Wz), new Vector2(dc.Tx2, dc.Ty1), c);
-            _DrawTexture(vert, texture.D3DTexture, _CalculateRotationMatrix(dc.Rotation, dc.Wx1, dc.Wx2, dc.Wy1, dc.Wy2));
+            _AddToVertexBuffer(vert, texture.D3DTexture, _CalculateRotationMatrix(dc.Rotation, dc.Wx1, dc.Wx2, dc.Wy1, dc.Wy2));
         }
 
         /// <summary>
@@ -455,7 +461,7 @@ namespace Vocaluxe.Lib.Draw
         /// <param name="vertices">A TexturedColoredVertex array containg 4 vertices</param>
         /// <param name="tex">The texture the vertex should be textured with</param>
         /// <param name="rotation">The vertices' rotation</param>
-        private void _DrawTexture(STexturedColoredVertex[] vertices, Texture tex, Matrix rotation)
+        private void _AddToVertexBuffer(STexturedColoredVertex[] vertices, Texture tex, Matrix rotation)
         {
             //The vertexbuffer is full, so we need to flush it before we can continue
             if (_Vertices.Count >= CSettings.VertexBufferElements)

Vocaluxe/Lib/Draw/CDrawBase.cs

@@ -260,13 +260,6 @@ namespace Vocaluxe.Lib.Draw
             drawCoords.Ty2 = Math.Min(1, (bounds.Bottom - rect.Y) / rect.H) * texture.HeightRatio;
             drawCoords.Wy2 = Math.Min(rect.Bottom, bounds.Bottom);
 
-            //TODO: Check this:
-            /*//Align the pixels because Direct3D expects the pixels to be the left top corner
-            rx1 -= 0.5f;
-            ry1 -= 0.5f;
-            rx2 -= 0.5f;
-            ry2 -= 0.5f;*/
-
             if (mirrored)
             {
                 float tmp = drawCoords.Ty1;

Vocaluxe/Lib/Draw/COpenGL.cs

@@ -440,6 +440,12 @@ namespace Vocaluxe.Lib.Draw
         #region drawing
         private static void _DrawTexture(COGLTexture texture, SDrawCoords dc, SColorF color, bool isReflection = false)
         {
+            // Align textures to full pixels to reduce artefacts
+            dc.Wx1 = (float)Math.Round(dc.Wx1);
+            dc.Wy1 = (float)Math.Round(dc.Wy1);
+            dc.Wx2 = (float)Math.Round(dc.Wx2);
+            dc.Wy2 = (float)Math.Round(dc.Wy2);
+
             GL.BindTexture(TextureTarget.Texture2D, texture.Name);
 
             GL.Enable(EnableCap.Blend);