Extract scene hiearchy and matrices, render recursively

src/nol/core.clj

@@ -3,7 +3,7 @@
    [clojure.math])
   (:import
    [java.nio FloatBuffer IntBuffer]
-   [org.lwjgl.assimp AIColor4D AIMaterial AIMesh AIScene AIString AITexture Assimp]
+   [org.lwjgl.assimp AIColor4D AIMaterial AIMatrix4x4 AIMesh AINode AIScene AIString AITexture Assimp]
    [org.lwjgl.glfw GLFW GLFWKeyCallbackI]
    [org.lwjgl.opengl GL GL11 GL20 GL30 GL45]
    [org.lwjgl.stb STBImage]
@@ -44,10 +44,55 @@
       (throw (RuntimeException. (str "Program link error: " (GL20/glGetProgramInfoLog program)))))
     program))
 
-(def loaded-scenes (atom []))
+(defn ai-matrix->matrix4f [^AIMatrix4x4 m]
-(def uploaded-scenes (atom []))
+  (Matrix4f. (.a1 m) (.a2 m) (.a3 m) (.a4 m)
+             (.b1 m) (.b2 m) (.b3 m) (.b4 m)
+             (.c1 m) (.c2 m) (.c3 m) (.c4 m)
+             (.d1 m) (.d2 m) (.d3 m) (.d4 m)))
+
+(defn matrix4f->vectors [^Matrix4f m]
+  [(vector (.m00 m) (.m01 m) (.m02 m) (.m03 m))
+   (vector (.m10 m) (.m11 m) (.m12 m) (.m13 m))
+   (vector (.m20 m) (.m21 m) (.m22 m) (.m23 m))
+   (vector (.m30 m) (.m31 m) (.m32 m) (.m33 m))])
+
+(defn node-matrix4f [^AINode c]
+  (-> c
+      (.mTransformation)
+      (ai-matrix->matrix4f)))
+
+(defn node-matrix [^AINode c]
+  (-> c
+      (.mTransformation)
+      (ai-matrix->matrix4f)
+      (matrix4f->vectors)))
+
+(def loaded-scene (atom nil))
+(def uploaded-scene (atom nil))
 (def shaders (atom nil))
 
+(defn render-scene [scene node mtx]
+  (when-let [mesh-indices (seq (:meshes node))]
+    (let [{:keys [gl-meshes gl-textures]} scene
+          {:keys [program uniforms]} @shaders]
+      (doseq [idx mesh-indices
+              :let [gl-mesh (nth gl-meshes idx)
+                    mesh (:mesh gl-mesh)
+                    [r g b a] (:color mesh)
+                    tex-idx (:texture-idx mesh)]]
+        (GL20/glUniform4f (:color uniforms) r g b a)
+        (GL20/glUniformMatrix4fv (:mm uniforms) false mtx #_(:transform node))
+        (GL30/glBindVertexArray (:vao gl-mesh))
+        (when tex-idx
+          (let [tex-id (:gl-id (nth gl-textures tex-idx))]
+            (GL45/glActiveTexture GL45/GL_TEXTURE0)
+            (GL11/glBindTexture GL11/GL_TEXTURE_2D tex-id)
+            (GL20/glUniform1i (:tex uniforms) 0)))
+        (GL11/glDrawElements GL11/GL_TRIANGLES (:indices-count gl-mesh) GL11/GL_UNSIGNED_INT 0))))
+  (when-let [children (seq (:children node))]
+    (doseq [child children]
+      (render-scene scene child mtx))))
+
 (defn- update-loop [window stack data]
   (let [w-buf (.mallocInt stack 1)
         h-buf (.mallocInt stack 1)
@@ -57,31 +102,20 @@
         t (GLFW/glfwGetTime)]
     (GL11/glViewport 0 0 w h)
     (GL11/glClear GL11/GL_COLOR_BUFFER_BIT)
+    (GL11/glClear (bit-or GL11/GL_COLOR_BUFFER_BIT GL11/GL_DEPTH_BUFFER_BIT))
 
     ;; (swap! state assoc :last-time t)
     (try
-      (when (and (seq @uploaded-scenes) @shaders)
+      (when (and @uploaded-scene @shaders)
-        (doseq [scene @uploaded-scenes
+        (let [scene @uploaded-scene
-                :let [{:keys [meshes gl-meshes gl-textures]} scene
+              {:keys [program uniforms]} @shaders]
-                      {:keys [program uniforms]} @shaders]]
           (GL20/glUseProgram program)
-          (doseq [m gl-meshes
+          (let [buf (.mallocFloat stack 16)
-                  :let [[r g b a] (:color (:mesh m))
+                m (Matrix4f.)]
-                        tex-idx (:texture-idx (:mesh m))]]
+            (.get m buf)
-            (GL20/glUniform4f (:color uniforms) r g b a)
+            (GL20/glUniformMatrix4fv (:mv uniforms) false buf)
-            (let [buf (.mallocFloat stack 16)
+            (GL20/glUniformMatrix4fv (:mp uniforms) false buf)
-                  m (Matrix4f.)]
+            (render-scene scene (:hiearchy scene) buf))))
-              (.get m buf)
-              (GL20/glUniformMatrix4fv (:mm uniforms) false buf)
-              (GL20/glUniformMatrix4fv (:mv uniforms) false buf)
-              (GL20/glUniformMatrix4fv (:mp uniforms) false buf))
-            (GL30/glBindVertexArray (:vao m))
-            (when tex-idx
-              (let [tex-id (:gl-id (nth gl-textures tex-idx))]
-                (GL45/glActiveTexture GL45/GL_TEXTURE0)
-                (GL11/glBindTexture GL11/GL_TEXTURE_2D tex-id)
-                (GL20/glUniform1i (:tex uniforms) 0)))
-            (GL11/glDrawElements GL11/GL_TRIANGLES (:indices-count m) GL11/GL_UNSIGNED_INT 0))))
       (catch Exception e
         (println "Update Loop GL thread error:" e)))
 
@@ -91,7 +125,7 @@
     (GLFW/glfwSwapBuffers window)))
 
 (defn stop! []
-  (reset! uploaded-scenes [])
+  (reset! uploaded-scene nil)
   (reset! shaders nil)
   (with-gl
     (GLFW/glfwSetWindowShouldClose
@@ -105,7 +139,7 @@
   (GLFW/glfwWindowHint GLFW/GLFW_CONTEXT_VERSION_MINOR 5)
   (GLFW/glfwWindowHint GLFW/GLFW_OPENGL_PROFILE GLFW/GLFW_OPENGL_CORE_PROFILE)
 
-  (let [window (GLFW/glfwCreateWindow 960 #_1900 300 #_1100 "NOL" MemoryUtil/NULL MemoryUtil/NULL)]
+  (let [window (GLFW/glfwCreateWindow 960 300 #_#_1900 1100 "NOL" MemoryUtil/NULL MemoryUtil/NULL)]
     (when (= window MemoryUtil/NULL)
       (GLFW/glfwTerminate)
       (throw (RuntimeException. "Failed to create window")))
@@ -199,6 +233,14 @@
                       Assimp/aiProcess_FlipUVs)]
     (Assimp/aiImportFile path flags)))
 
+(defn traverse [^AINode node]
+  {:node node
+   :meshes (let [buf (.mMeshes node)]
+             (mapv #(.get buf %) (range (.mNumMeshes node))))
+   :transform (node-matrix4f node)
+   :children (mapv #(traverse (AINode/create ^long (.get (.mChildren node) %)))
+                   (range (.mNumChildren node)))})
+
 (defn load-scene [path]
   (let [scene (load-model path)
         meshes (doall
@@ -213,8 +255,10 @@
                              h (int-array 1)
                              channels (int-array 1)]
                          {:data (STBImage/stbi_load_from_memory buf w h channels 4)
-                          :w (aget w 0) :h (aget h 0)}))))]
+                          :w (aget w 0) :h (aget h 0)}))))
-    {:scene scene :meshes meshes :textures textures}))
+        hiearchy (traverse (.mRootNode scene))]
+    (Assimp/aiReleaseImport scene)
+    {:meshes meshes :textures textures :hiearchy hiearchy}))
 
 (defn upload-scene! [scene]
   (let [gl-meshes
@@ -264,16 +308,17 @@
                 :mv (GL20/glGetUniformLocation program "uView")
                 :mp (GL20/glGetUniformLocation program "uProjection")}}))
 
+(reset! loaded-scene (load-scene "assets/model.glb"))
+
 (comment
   (start!)
   (stop!)
 
-  (@loaded-scenes)
+  (reset! uploaded-scene (with-gl (upload-scene! @loaded-scene)))
-
-  (swap! loaded-scenes conj (load-scene "assets/model.glb"))
-  (swap! uploaded-scenes conj (with-gl (upload-scene! (first @loaded-scenes))))
   (reset! shaders (with-gl (load-shaders! "shaders/base.vert" "shaders/base.frag")))
 
+  (with-gl
+    (GL11/glClear (bit-or GL11/GL_COLOR_BUFFER_BIT GL11/GL_DEPTH_BUFFER_BIT)))
   (with-gl
     (GL11/glClearColor 0.392 0.584 0.929 1.0))
   (with-gl