Very significant improvement in performance by using glSubImage to upload data. Inspired by frequent complaints about performance of hires

texture packs. They probably still need a beefy system but should work. Hopefully I can figure out why the subImage GL side copy isn't working
properly for an even more significant speed boost. But this gets things started.

fml/client/cpw/mods/fml/client/CopySubimageTextureHelper.java

@@ -0,0 +1,30 @@
+package cpw.mods.fml.client;
+
+import java.nio.ByteBuffer;
+
+import org.lwjgl.opengl.GL11;
+
+import net.minecraft.client.renderer.texture.Texture;
+import net.minecraft.client.renderer.texture.TextureStitched;
+
+public class CopySubimageTextureHelper extends TextureHelper {
+    @Override
+    public void doTextureCopy(Texture atlas, Texture source, int atlasX, int atlasY)
+    {
+        if (atlas.func_94282_c() == -1)
+        {
+            return;
+        }
+        atlas.func_94277_a(0);
+        ByteBuffer buffer = source.func_94273_h();
+        buffer.position(0);
+        GL11.glTexSubImage2D(GL11.GL_TEXTURE_2D, 0, atlasX, atlasY, source.func_94275_d(), source.func_94276_e(), GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buffer);
+    }
+
+    @Override
+    public void doTextureUpload(TextureStitched source)
+    {
+        // NO OP for copysubimage
+    }
+
+}

fml/client/cpw/mods/fml/client/OpenGL43TextureHelper.java

@@ -0,0 +1,30 @@
+package cpw.mods.fml.client;
+
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL43;
+
+import net.minecraft.client.renderer.texture.Texture;
+import net.minecraft.client.renderer.texture.TextureStitched;
+
+public class OpenGL43TextureHelper extends TextureHelper {
+
+    public OpenGL43TextureHelper()
+    {
+//        GL43.
+//        glCopyMethod = Class.forName("org.lwjgl.OpenGL")
+    }
+    @Override
+    public void doTextureCopy(Texture atlas, Texture source, int atlasX, int atlasY)
+    {
+//        System.out.printf("Src: %d Targ: %d, Coords %d %d %d %d\n", source.func_94282_c(), atlas.func_94282_c(), atlasX, atlasY, source.func_94275_d(), source.func_94276_e());
+//        GL43.glCopyImageSubData(source.func_94282_c(), GL11.GL_TEXTURE_2D, 0, 0, 0, 0, atlas.func_94282_c(), GL11.GL_TEXTURE_2D, 0, atlasX, atlasY, 0, source.func_94275_d(), source.func_94276_e(), 1);
+//        System.out.printf("Err: %x\n", GL11.glGetError());
+    }
+
+    @Override
+    public void doTextureUpload(TextureStitched source)
+    {
+//        source.createAndUploadTextures();
+    }
+
+}

fml/client/cpw/mods/fml/client/TextureFXManager.java

@@ -20,8 +20,13 @@ import java.util.Map;
 
 import javax.imageio.ImageIO;
 
+import org.lwjgl.opengl.ContextCapabilities;
+import org.lwjgl.opengl.GLContext;
+
 import com.google.common.collect.Maps;
 
+import cpw.mods.fml.common.FMLLog;
+
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.RenderEngine;
 
@@ -34,6 +39,8 @@ public class TextureFXManager
     private Map<Integer,TextureHolder> texturesById = Maps.newHashMap();
     private Map<String, TextureHolder> texturesByName = Maps.newHashMap();
 
+    private TextureHelper helper;
+
     void setClient(Minecraft client)
     {
         this.client = client;
@@ -102,4 +109,35 @@ public class TextureFXManager
     {
         return texturesByName.containsKey(texture) ? new Dimension(texturesByName.get(texture).x, texturesByName.get(texture).y) : new Dimension(1,1);
     }
+
+
+    public TextureHelper getHelper()
+    {
+        if (helper == null)
+        {
+            ContextCapabilities capabilities = GLContext.getCapabilities();
+            boolean has43 = false;
+            try
+            {
+                has43 = capabilities.getClass().getField("GL_ARB_copy_image").getBoolean(capabilities);
+            }
+            catch (Exception e)
+            {
+                e.printStackTrace();
+                // NOOP - LWJGL needs updating
+                FMLLog.info("Forge Mod Loader has detected an older LWJGL version, new advanced texture animation features are disabled");
+            }
+//            if (has43 && Boolean.parseBoolean(System.getProperty("fml.useGL43","true")))
+//            {
+//                FMLLog.info("Using the new OpenGL 4.3 advanced capability for animations");
+//                helper = new OpenGL43TextureHelper();
+//            }
+//            else
+            {
+                FMLLog.info("Not using advanced OpenGL 4.3 advanced capability for animations : OpenGL 4.3 is %s", has43 ? "available" : "not available");
+                helper = new CopySubimageTextureHelper();
+            }
+        }
+        return helper;
+    }
 }

fml/client/cpw/mods/fml/client/TextureHelper.java

@@ -0,0 +1,64 @@
+package cpw.mods.fml.client;
+
+import java.nio.ByteBuffer;
+import java.util.List;
+
+import net.minecraft.client.renderer.texture.Texture;
+import net.minecraft.client.renderer.texture.TextureStitched;
+
+public abstract class TextureHelper {
+
+    /**
+     * Copy the texture from the source to the atlas at the specified position
+     *
+     * This will use the devised GL helper to do either GL-side copy or a subimage upload
+     *
+     * @param atlas The atlas texture we're copying into
+     * @param source The source texture we're copying from (complete)
+     * @param atlasX The X position on the atlas
+     * @param atlasY The Y position on the atlas
+     */
+    public abstract void doTextureCopy(Texture atlas, Texture source, int atlasX, int atlasY);
+
+    /**
+     * Upload the texture to the GPU for GL side copying operations
+     * This may be a no-op depending on the active implementation.
+     *
+     * @param source The texture to upload
+     */
+    public abstract void doTextureUpload(TextureStitched source);
+
+    /**
+     * Rotate the texture so that it doesn't need a rotational transform applied each tick
+     *
+     * @param texture The texture to rotate
+     * @param buffer The buffer for the texture
+     */
+    public void rotateTexture(Texture texture, ByteBuffer buffer)
+    {
+        ByteBuffer bytebuffer = buffer;
+        buffer.position(0);
+        ByteBuffer other = ByteBuffer.allocateDirect(buffer.capacity());
+        other.position(0);
+
+        for (int k = 0; k < texture.func_94276_e(); ++k)
+        {
+            int l = texture.func_94276_e() - k - 1;
+            int i1 = k * texture.func_94275_d() * 4;
+
+            for (int k1 = 0; k1 < texture.func_94275_d(); ++k1)
+            {
+                int l1 = k1 * texture.func_94276_e() * 4 + l * 4;
+                int i2 = i1 + k1 * 4;
+
+                other.put(l1 + 0, bytebuffer.get(i2 + 0));
+                other.put(l1 + 1, bytebuffer.get(i2 + 1));
+                other.put(l1 + 2, bytebuffer.get(i2 + 2));
+                other.put(l1 + 3, bytebuffer.get(i2 + 3));
+            }
+        }
+        buffer.position(0);
+        buffer.put(other);
+    }
+
+}