rotate those boxes

scene-graph-example.scg

@@ -52,7 +52,7 @@ rotateZ 0.0
 obj 1
 use 0
 name myCrate2
-translate 0.0 1.0 0.0
+translate 0.0 3.0 0.0
 scale 0.5 0.5 0.5
 # Definition des Parent Objekts
 parent 0

src/main.c

@@ -212,7 +212,7 @@ void init(void) {
     setNodeRenderFunction(&renderNode);
 
     // read scene graph
-    rootNode = loadSceneGraphFromFile("../scene-graph-example.scg");
+    rootNode = loadSceneGraphFromFile("../test-scene-graph.scg");
 
     // ENABLE BACKFACE CULLING
     glFrontFace(GL_CCW);
@@ -241,12 +241,14 @@ void draw(void) {
     timeSinceUpdate += deltaTime;
     glfwSetTime(0.0f);
 
+
     if (timeSinceUpdate >= timeBetweenUpdates) {
         updateStats();
         timeSinceUpdate = 0.0f;
         framesSinceUpdate = 0;
     }
 
+
     // camera movement
     handleInputs(deltaTime);
 
@@ -259,6 +261,10 @@ void draw(void) {
     if (step > 1.0f) step -= 1.0f;
     if (step < 0.0f) step += 1.0f;
 
+    SceneNode* box3 = findNodeByName("box3", rootNode);
+    rotateY(&box3->transformation, &box3->transformation, 0.001);
+    updateSceneNode(rootNode, NULL);
+
     // step multiplied by pi * 2 for use in rotation and trig functions
     GLfloat stepi = step * pi * 2;
 
@@ -291,7 +297,7 @@ void draw(void) {
     glUniform4f(glGetUniformLocation(program, "ambientLight"), 0.05f, 0.05f, 0.05f, 1.0f);
 
     vec4 lightPosition = {cos(stepi) * 5.0f, 5.0f, sin(stepi) * 5.0f, 1.0f};
-    multiplyAny(&lightPosition, &viewingTransformation, &lightPosition, 4, 4, 1);
+    multiplyAny((GLfloat*)&lightPosition, (GLfloat*)&viewingTransformation, (GLfloat*)&lightPosition, 4, 4, 1);
 
     glUniform3f(glGetUniformLocation(program, "lightPosition"), lightPosition.x, lightPosition.y, lightPosition.z);
 

src/sceneGraph.c

@@ -55,7 +55,9 @@ void addChild(SceneNode* parent, SceneNode* child) {
 }
 
 void updateSceneNode(SceneNode* node, mat4* parentTransformation) {
+    if (parentTransformation) {
         multiply(&node->worldTransformation, parentTransformation, &node->transformation);
+    }
     for (int i = 0; i < node->numChildren; i++) {
         updateSceneNode(node->children[i], &node->worldTransformation);
     }
@@ -116,6 +118,15 @@ SceneNode* findNode(int id, SceneNode* root) {
     return NULL;
 }
 
+SceneNode* findNodeByName(char* name, SceneNode* root) {
+    if (root->name && strcmp(root->name, name) == 0) return root;
+    for (int i = 0; i < root->numChildren; i++) {
+        SceneNode* node = findNodeByName(name, root->children[i]);
+        if (node) return node;
+    }
+    return NULL;
+}
+
 void printSceneGraph(SceneNode* node, int level) {
     for (int i = 0; i < level; i++) {
         printf(" - ");
@@ -324,9 +335,7 @@ SceneNode* loadSceneGraphFromFile(char* path) {
         addChild(root, currentNode);
     }
 
-    mat4 rootTransform;
+    updateSceneNode(root, NULL);
-    identity(&rootTransform);
-    updateSceneNode(root, &rootTransform);
 
     printSceneGraph(root, 0);
 

src/sceneGraph.h

@@ -26,12 +26,15 @@ struct SceneNode {
     char* name;
 };
 
+extern SceneNode* findNode(int id, SceneNode* root);
+extern SceneNode* findNodeByName(char* name, SceneNode* root);
 extern void setNodeRenderFunction(void (*newRenderFunction)(SceneNode*));
 extern SceneNode* createSceneNode();
 extern void addChild(SceneNode* parent, SceneNode* child);
 extern void updateSceneNode(SceneNode* node, mat4* parentTransformation);
 extern void renderSceneNode(SceneNode* node);
 extern void freeSceneNode(SceneNode* node);
+extern void printSceneGraph(SceneNode* root, int level);
 extern SceneNode* loadSceneGraphFromFile(char* path);
 
 #endif

test-scene-graph.scg

@@ -4,23 +4,35 @@ texture ../texture/crate/texture.jpg
 
 obj 0
 use 0
-scale 0.1 1.0 0.1
+scale 1.0 0.3 1.0
 name box1
 
 obj 1
 parent 0
-scale 0.2 0.8 0.2
+translate 2.0 0.0 0.0
-translate 0.5 0.0 0.0
-name box2
 
 obj 2
+use 0
 parent 1
-scale 0.3 0.6 0.3
+scale 0.7 1.5 0.7
-translate 0.5 0.0 0.0
+name box2
-name box3
 
 obj 3
 parent 2
-scale 0.4 0.4 0.4
+translate 2.0 0.0 0.0
-translate 0.5 0.0 0.0
+
+obj 4
+use 0
+parent 3
+scale 0.7 1.5 0.7
+name box3
+
+obj 5
+parent 4
+translate 2.0 0.0 0.0
+
+obj 6
+use 0
+parent 5
+scale 0.7 1.5 0.7
 name box4