Update progress.

README.md

@@ -36,7 +36,8 @@ Two caps and many strips composites a cylinder.
 Almost all 3D editor have a infinite grid ground, I just made a finite one, in the future, I should expand the grid outside of the screen to make it infinite.  
 Now, for just beginning, I think it's a not bad start.
 <img src="screenshot/dust3d_sphere_cylinder.png">
-- [ ] Implement B-Mesh algorithm (Dec 18, 2016 ~ Dec 31, 2016)   
+- [ ] Implement B-Mesh algorithm (Dec 18, 2016 ~ Jan 02, 2017)   
+There is a implementation of [B-Mesh algorithm in C++](https://github.com/evanw/cs224final) language, but I want the pure C version, so I start to implement my own version. I read both paper and this implementation, it gave me very helpful understanding of this algorithm.    
 *Drawing Skeletal Shape Balls*  
 Draw shape ball is easy, no need to rotate, I just need scale it along the ball's radius.
 Draw the cylinder which connects two shape balls is more difficult, I need do some math to rotate it. [Here](http://www.thjsmith.com/40/cylinder-between-two-points-opengl-c) described it.  
@@ -55,10 +56,14 @@ I created the test nodes's geometry information from Blender. Here is the render
 When I am implementing the B-Mesh algorithm, I am also think in the future, how to create a library of bunch of initial base models. There is a paper [the Skeleton of a Closed 3D Shape](http://www1.idc.ac.il/icgf/GraphicsSeminar2006/DCGskeleton06.pdf) described how to generate skeleton from mesh, this is the reverse progress of what I am doing, I think it can resolve the problem of insufficient initial base models, I can generate from tons of existed models.  
 *Convex Hull*  
 After finish the rotation at the two connected bones, I need implement 3D Convex Hull algorithm at the joint ball, there are so many methods to get the convex hull, I found the [Gift wrapping](http://dccg.upc.edu/people/vera/wp-content/uploads/2014/11/GA2014-ConvexHulls3D-Roger-Hernando.pdf) is the most strait-forward one, though is not the most efficient one.  
+There is a good implementation of [Gift Wrapping algorithm written in lua](https://github.com/danielhst/3d-Hull-gift-wrap/blob/master/giftWrap.lua) language. When I was implementing, I first translated this version to C language, but maybe there are some bugs on my own translation, there are lots of repeated faces, so changed a little, the code now is not just the translation of the original lua version.  
 <img src="screenshot/dust3d_convex_hull.png" width="124" height="128">  
 *Stitching*  
 I follow the B-Mesh paper, made another test module inside Blender, and created a correspond `data/bmesh_test_2.h` manually.  
 <img src="screenshot/dust3d_bmesh_test_2.png" width="124" height="128">  <img src="screenshot/dust3d_bmesh_joint_1.png" width="124" height="128">  <img src="screenshot/dust3d_bmesh_joint_2.png" width="124" height="128">  
+*Catmull-Clark Subdivision*  
+<img src="screenshot/dust3d_subdivide_catmull_clark.png" width="124" height="128">    
+There is a implementation of Catmull-Clark Subdivision algorithm on [rosettacode](https://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface/C), the code is very simple and beautiful, just lack of some memory alloc fail check. I translated the algorithm to use my own array implementation.  
 - [ ] Export Wavefront .obj  
 - [ ] Render B-Mesh result  
 - [ ] Design UI for monster parts configuration  

build/dust3d.pro

@@ -17,7 +17,8 @@ SOURCES += main.cpp \
   matrix.c \
   convexhull.c \
   hashtable.c \
-  osutil.cpp
+  osutil.cpp \
+  subdivide.c
 
 HEADERS += mainwindow.h \
 	render.h \
@@ -29,4 +30,5 @@ HEADERS += mainwindow.h \
   convexhull.h \
   hashtable.h \
   3dstruct.h \
-  osutil.h
+  osutil.h \
+  subdivide.h

src/3dstruct.h

@@ -1,6 +1,7 @@
 #ifndef _3DSTRUCT_H
 #define _3DSTRUCT_H
 #include "vector3d.h"
+#include "array.h"
 
 typedef struct {
   vec3 pt[3];

src/convexhull.c

@@ -539,9 +539,8 @@ int convexHullMergeTriangles(convexHull *hull) {
       e->score = (int)angle;
       //if (edgeIndex >= 12 && edgeIndex <= 12) {
       //  angle = (int)vec3Angle(&f1normal, &f2normal);
-      //  drawDebugPrintf("edgeIndex:%d angle:%f normal1:<%f,%f,%f> normal2:<%f,%f,%f>",
-      //    edgeIndex, angle, f1normal.x, f1normal.y, f1normal.z,
-      //    f2normal.x, f2normal.y, f2normal.z);
+        drawDebugPrintf("edgeIndex:%d angle:%f",
+          edgeIndex, angle);
       //}
     }
   }
@@ -564,7 +563,7 @@ int convexHullMergeTriangles(convexHull *hull) {
       convexHullFace *f2 = (convexHullFace *)arrayGetItem(hull->faceArray,
         e->face2);
       if (3 == f1->vertexNum && 3 == f2->vertexNum) {
-        if (e->score <= 0) {
+        if (e->score <= 40) {
           while (e->p1 == f1->u.t.indices[0] || e->p2 == f1->u.t.indices[0]) {
             rollTriangleIndices((face3 *)f1);
           }

src/hashtable.c

@@ -31,18 +31,18 @@ hashtable *hashtableCreate(int bucketSize,
     void *userData) {
   hashtable *ht = (hashtable *)calloc(1, sizeof(hashtable));
   if (!ht) {
-    fprintf(stderr, "%s:Insufficient memory.", __FUNCTION__);
+    fprintf(stderr, "%s:Insufficient memory.\n", __FUNCTION__);
     return 0;
   }
   ht->keyArray = arrayCreate(sizeof(hashtableKey));
   if (!ht->keyArray) {
-    fprintf(stderr, "%s:arrayCreate failed.", __FUNCTION__);
+    fprintf(stderr, "%s:arrayCreate failed.\n", __FUNCTION__);
     hashtableDestroy(ht);
     return 0;
   }
   ht->entryArray = arrayCreate(sizeof(hashtableEntry));
   if (!ht->entryArray) {
-    fprintf(stderr, "%s:arrayCreate failed.", __FUNCTION__);
+    fprintf(stderr, "%s:arrayCreate failed.\n", __FUNCTION__);
     hashtableDestroy(ht);
     return 0;
   }
@@ -51,7 +51,7 @@ hashtable *hashtableCreate(int bucketSize,
   ht->compareCallback = compareCallback;
   ht->userData = userData;
   if (0 != arraySetLength(ht->keyArray, bucketSize)) {
-    fprintf(stderr, "%s:arraySetLength failed(bucketSize:%d).", __FUNCTION__,
+    fprintf(stderr, "%s:arraySetLength failed(bucketSize:%d).\n", __FUNCTION__,
       bucketSize);
     hashtableDestroy(ht);
     return 0;
@@ -98,7 +98,7 @@ int hashtableInsert(hashtable *ht, const void *node) {
   }
   newEntryIndex = arrayGetLength(ht->entryArray);
   if (0 != arraySetLength(ht->entryArray, newEntryIndex + 1)) {
-    fprintf(stderr, "%s:arraySetLength failed(newEntryIndex:%d).",
+    fprintf(stderr, "%s:arraySetLength failed(newEntryIndex:%d).\n",
       __FUNCTION__, newEntryIndex);
     return -1;
   }

src/render.cpp

@@ -7,6 +7,7 @@
 #include "bmesh.h"
 #include "matrix.h"
 #include "vector3d.h"
+#include "subdivide.h"
 
 static const float bmeshBallColors[][4] {
   {0.00, 0.78, 1.00, 0.5},
@@ -212,7 +213,7 @@ void Render::initializeGL() {
   drawInit();
 }
 
-#include "../data/bmesh_test_2.h"
+#include "../data/bmesh_test_1.h"
 
 void Render::paintGL() {
   bmesh *bm = 0;
@@ -236,7 +237,16 @@ void Render::paintGL() {
 
   glEnable(GL_LIGHTING);
   
-  if (0 == bm) {
+  {
+    subdivModel *input = subdivCreateModel();
+    subdivModel *output;
+    subdivAddCube(input);
+    output = subdivCatmullClarkWithLoops(input, 2);
+    subdivDestroyModel(input);
+    subdivDestroyModel(output);
+  }
+
+  if (0 && 0 == bm) {
     bmeshBall ball;
     bmeshBone bone;
     int i;
@@ -265,6 +275,8 @@ void Render::paintGL() {
     bmeshGenerateInbetweenMesh(bm);
   }
   
+  if (bm) {
+
     drawBmeshBallRecursively(bm, bmeshGetRootBall(bm));
 
     //glBegin(GL_QUADS);
@@ -309,6 +321,7 @@ void Render::paintGL() {
         glEnd();
       }*/
     }
+  }
 
   glPopMatrix();
   

src/vector3d.c

@@ -137,3 +137,9 @@ float vec3TriangleArea(vec3 *a, vec3 *b, vec3 *c) {
   vec3CrossProduct(&ab, &ac, &cross);
   return vec3Length(&cross) * 0.5;
 }
+
+void vec3Negative(vec3 *a, vec3 *result) {
+  result->x = -a->x;
+  result->y = -a->y;
+  result->z = -a->z;
+}

src/vector3d.h

@@ -26,6 +26,7 @@ void vec3RotateAlong(vec3 *a, float angle, vec3 *axis, vec3 *result);
 float vec3Angle(vec3 *a, vec3 *b);
 void vec3ProjectOver(vec3 *a, vec3 *over, vec3 *result);
 float vec3TriangleArea(vec3 *a, vec3 *b, vec3 *c);
+void vec3Negative(vec3 *a, vec3 *result);
 
 #ifdef __cplusplus
 }