Add .blend export

src/main/java/com/replaymod/render/blend/BlendMaterials.java

@@ -0,0 +1,70 @@
+package com.replaymod.render.blend;
+
+import com.replaymod.render.blend.data.DImage;
+import com.replaymod.render.blend.data.DMaterial;
+import com.replaymod.render.blend.data.DPackedFile;
+import com.replaymod.render.blend.data.DTexture;
+import net.minecraft.client.renderer.GLAllocation;
+import org.apache.commons.lang3.tuple.Pair;
+import org.lwjgl.opengl.GL11;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.awt.image.DataBufferByte;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.HashMap;
+import java.util.Map;
+
+public class BlendMaterials {
+    private final Map<Integer, DMaterial> materials = new HashMap<>();
+
+    public DMaterial getActiveMaterial() {
+        int textureId = GL11.glGetInteger(GL11.GL_TEXTURE_BINDING_2D);
+        DMaterial material = materials.get(textureId);
+        if (material == null) {
+            // Read raw image data from GL
+            int width = GL11.glGetTexLevelParameteri(GL11.GL_TEXTURE_2D, 0, GL11.GL_TEXTURE_WIDTH);
+            int height = GL11.glGetTexLevelParameteri(GL11.GL_TEXTURE_2D, 0, GL11.GL_TEXTURE_HEIGHT);
+            ByteBuffer buffer = GLAllocation.createDirectByteBuffer(width * height * 4);
+            GL11.glGetTexImage(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buffer);
+
+            // Convert to BufferedImage
+            BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_4BYTE_ABGR);
+            byte[] data = ((DataBufferByte) bufferedImage.getRaster().getDataBuffer()).getData();
+            for (int i = 0; i < data.length; i += 4) {
+                data[i + 3] = buffer.get();
+                data[i + 2] = buffer.get();
+                data[i + 1] = buffer.get();
+                data[i    ] = buffer.get();
+            }
+
+            // Encode as png image
+            ByteArrayOutputStream stream = new ByteArrayOutputStream();
+            try {
+                ImageIO.write(bufferedImage, "png", stream);
+            } catch (IOException e) {
+                throw new RuntimeException(e); // never happens unless ImageIO is bugged
+            }
+            byte[] bytes = stream.toByteArray();
+
+            // Wrap into blender structs
+            DImage image = new DImage();
+            image.id.name = "texture.png";
+            image.filePath = "texture.png";
+            image.packedFiles.add(Pair.of("texture.png", new DPackedFile(bytes)));
+
+            DTexture texture = new DTexture();
+            texture.image = image;
+
+            DMaterial.DMTex mTex = new DMaterial.DMTex();
+            mTex.texture = texture;
+
+            material = new DMaterial();
+            material.textures.add(mTex);
+            materials.put(textureId, material);
+        }
+        return material;
+    }
+}