Use glu to draw primitives

README.md

@@ -26,9 +26,10 @@ Now, for just beginning, I think it's a not bad start.
 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.  
 *Camera Control*  
-Camera rotate/zoom implemented, [here](http://www.songho.ca/opengl/gl_transform.html) is a good article which explained the theory of OpenGL Transformation. Most important is the demo apps all are very beautiful.
-<img src="screenshot/dust3d_node_edge.png">
+Camera rotate/zoom implemented, [here](http://www.songho.ca/opengl/gl_transform.html) is a good article which explained the theory of OpenGL Transformation. Most important is that the demo app is very beautiful.  
 Added x,z axis, looks better than last screenshot.   
+I have to use the GLU library, the previous implementation of drawSphere and drawCylinder looks not good, and take too much time to debug.
+<img src="screenshot/dust3d_node_edge_with_glu.png">
 - [ ] Export Wavefront .obj  
 - [ ] Render B-Mesh result  
 - [ ] Design UI for monster parts configuration  

src/draw.cpp

@@ -3,110 +3,28 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef __APPLE__
+#include <OpenGL/glu.h>
+#else
+#include <GL/glu.h>
+#endif
 #include "draw.h"
 
-/*
- * This drawSphere function modified from [Jon Leech's implementation of sphere](ftp://ftp.ee.lbl.gov/sphere.c)
- * Jeremy HU (huxingyi@msn.com) 2016/12/16
-*/
+static GLUquadricObj *quadricId = 0;
 
-#define XPLUS {  1,  0,  0 }  /*  X */
-#define XMIN  { -1,  0,  0 }  /* -X */
-#define YPLUS {  0,  1,  0 }  /*  Y */
-#define YMIN  {  0, -1,  0 }  /* -Y */
-#define ZPLUS {  0,  0,  1 }  /*  Z */
-#define ZMIN  {  0,  0, -1 }  /* -Z */
-
-static const triangle octahedron[] = {
-  {{XPLUS, ZPLUS, YPLUS}},
-  {{YPLUS, ZPLUS, XMIN}},
-  {{XMIN,  ZPLUS, YMIN}},
-  {{YMIN,  ZPLUS, XPLUS}},
-  {{XPLUS, YPLUS, ZMIN}},
-  {{YPLUS, XMIN,  ZMIN}},
-  {{XMIN,  YMIN,  ZMIN}},
-  {{YMIN,  XPLUS, ZMIN}},
-};
-
-static void subdivide(object *old, object *subdivided) {
-  int i;
-  for (i = 0; i < old->npoly; ++i) {
-    triangle *oldt = &old->poly[i];
-    triangle *newt = &subdivided->poly[i * 4];
-    vec3 a, b, c;
-
-    vec3Midpoint(&oldt->pt[0], &oldt->pt[2], &a);
-    vec3Midpoint(&oldt->pt[0], &oldt->pt[1], &b);
-    vec3Midpoint(&oldt->pt[1], &oldt->pt[2], &c);
-
-    vec3Normalize(&a);
-    vec3Normalize(&b);
-    vec3Normalize(&c);
-
-    newt->pt[0] = oldt->pt[0];
-    newt->pt[1] = b;
-    newt->pt[2] = a;
-    newt++;
-
-    newt->pt[0] = b;
-    newt->pt[1] = oldt->pt[1];
-    newt->pt[2] = c;
-    newt++;
-
-    newt->pt[0] = a;
-    newt->pt[1] = b;
-    newt->pt[2] = c;
-    newt++;
-
-    newt->pt[0] = a;
-    newt->pt[1] = c;
-    newt->pt[2] = oldt->pt[2];
+int drawInit(void) {
+  if (0 == quadricId) {
+    quadricId = gluNewQuadric();
+    gluQuadricDrawStyle(quadricId, GLU_FILL);
   }
+  return 0;
 }
 
-int drawSphere(vec3 *origin, float radius, int level) {
-  int lv, i;
-  object oldObj, newObj;
-
-  if (level < 1) {
-    fprintf(stderr, "%s:level max greater than 0.\n", __FUNCTION__);
-    return -1;
-  }
-
-  oldObj.npoly = sizeof(octahedron) / sizeof(octahedron[0]);
-  oldObj.poly = (triangle *)malloc(oldObj.npoly * sizeof(triangle));
-  if (!oldObj.poly) {
-    fprintf(stderr, "%s:insufficient memory.\n", __FUNCTION__);
-    return -1;
-  }
-  memcpy(oldObj.poly, octahedron, oldObj.npoly * sizeof(triangle));
-
-  for (lv = 0; lv < level; lv++) {
-    newObj.npoly = oldObj.npoly * 4;
-    newObj.poly = (triangle *)malloc(newObj.npoly * sizeof(triangle));
-    if (!newObj.poly) {
-      fprintf(stderr, "%s:insufficient memory(levelLoop:%d).\n",
-        __FUNCTION__, lv);
-      free(oldObj.poly);
-      return -1;
-    }
-
-    subdivide(&oldObj, &newObj);
-
-    free(oldObj.poly);
-    oldObj = newObj;
-  }
-
+int drawSphere(vec3 *origin, float radius, int slices, int stacks) {
   glPushMatrix();
   glTranslatef(origin->x, origin->y, origin->z);
-  glScalef(radius, radius, radius);
-  for (i = 0; i < newObj.npoly; ++i) {
-    drawTriangle(&newObj.poly[i]);
-  }
+  gluSphere(quadricId, radius, slices, stacks);
   glPopMatrix();
-
-  free(newObj.poly);
-
   return 0;
 }
 
@@ -121,11 +39,8 @@ void drawTriangle(triangle *poly) {
   glEnd();
 }
 
-int drawCylinder(vec3 *topOrigin, vec3 *bottomOrigin, float radius, int slices) {
-  float theta = (2.0 * M_PI) / (float)slices;
-  float a = 0.0f;
-  int lv;
-  float x, y, z;
+int drawCylinder(vec3 *topOrigin, vec3 *bottomOrigin, float radius, int slices,
+    int stacks) {
   vec3 zAxis = {0, 0, 1};
   vec3 p, t;
   float height = 0;
@@ -148,51 +63,7 @@ int drawCylinder(vec3 *topOrigin, vec3 *bottomOrigin, float radius, int slices)
   glTranslatef(bottomOrigin->x, bottomOrigin->y,
     bottomOrigin->z);
   glRotatef(angle, t.x, t.y, t.z);
-
-  // strips
-  glBegin(GL_TRIANGLE_STRIP);
-  for (a = 0, lv = 0; lv <= slices; ++lv) {
-    float cosa = cos(a);
-    float sina = sin(a);
-    x = cosa * radius;
-    y = sina * radius;
-    z = 0;
-    glNormal3f(cosa, sina, 0);
-    glVertex3f(x, y, z);
-    z = height;
-    glNormal3f(cosa, sina, 0);
-    glVertex3f(x, y, z);
-    a += theta;
-  }
-  glEnd();
-
-  // bottom cap
-  z = 0;
-  glBegin(GL_TRIANGLE_FAN);
-  glNormal3f(0, 0, -1);
-  glVertex3f(0, 0, z);
-  for (a = 0, lv = 0; lv <= slices; ++lv) {
-    x = cos(a) * radius;
-    y = sin(a) * radius;
-    glNormal3f(0, 0, -1);
-    glVertex3f(x, y, z);
-    a += theta;
-  }
-  glEnd();
-
-  // top cap
-  z = height;
-  glBegin(GL_TRIANGLE_FAN);
-  glNormal3f(0, 0, 1);
-  glVertex3f(0, 0, z);
-  for (a = 0, lv = 0; lv <= slices; ++lv) {
-    x = cos(a) * radius;
-    y = sin(a) * radius;
-    glNormal3f(0, 0, 1);
-    glVertex3f(x, y, z);
-    a += theta;
-  }
-  glEnd();
+  gluCylinder(quadricId, radius, radius, height, slices, stacks);
 
   glPopMatrix();
 

src/draw.h

@@ -15,9 +15,11 @@ typedef struct {
   triangle *poly;
 } object;
 
-int drawSphere(vec3 *origin, float radius, int level);
+int drawInit(void);
+int drawSphere(vec3 *origin, float radius, int slices, int stacks);
 void drawTriangle(triangle *poly);
-int drawCylinder(vec3 *topOrigin, vec3 *bottomOrigin, float radius, int slices);
+int drawCylinder(vec3 *topOrigin, vec3 *bottomOrigin, float radius, int slices,
+    int stacks);
 int drawGrid(float size, float step);
 
 #ifdef __cplusplus

src/drawcommon.h

@@ -1,25 +0,0 @@
-#ifndef DRAW_COMMON_H
-#define DRAW_COMMON_H
-#include "vector3d.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-typedef struct {
-  vec3 pt[3];
-} triangle;
-
-typedef struct {
-  int npoly;
-  triangle *poly;
-} object;
-
-void drawTriangle(triangle *poly);
-int drawCylinder(int slices, float radius, float height);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif

src/render.cpp

@@ -10,7 +10,7 @@
 static int drawBmeshNode(bmesh *bm, bmeshNode *node) {
   float color1[3] = {1, 0, 0};
   glColor3fv(color1);
-  drawSphere(&node->position, node->radius, 3);
+  drawSphere(&node->position, node->radius, 36, 24);
   return 0;
 }
 
@@ -19,7 +19,7 @@ static int drawBmeshEdge(bmesh *bm, bmeshEdge *edge) {
   glColor3fv(color2);
   bmeshNode *firstNode = bmeshGetNode(bm, edge->firstNode);
   bmeshNode *secondNode = bmeshGetNode(bm, edge->secondNode);
-  drawCylinder(&firstNode->position, &secondNode->position, 0.04, 40);
+  drawCylinder(&firstNode->position, &secondNode->position, 0.1, 36, 24);
   return 0;
 }
 
@@ -31,8 +31,8 @@ Render::Render(QWidget *parent)
 
   mouseX = 0;
   mouseY = 0;
-  cameraAngleX = 50;
-  cameraAngleY = 70;
+  cameraAngleX = 45;
+  cameraAngleY = -45;
   cameraDistance = 3;
 }
 
@@ -74,6 +74,8 @@ void Render::initializeGL() {
 
   glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
   glEnable(GL_COLOR_MATERIAL);
+
+  drawInit();
 }
 
 void Render::paintGL() {
@@ -97,17 +99,17 @@ void Render::paintGL() {
     bm = bmeshCreate();
 
     memset(&node, 0, sizeof(node));
-    node.position.x = -1.0;
-    node.position.y = 0.3;
-    node.position.z = 1.0;
-    node.radius = 0.45;
+    node.position.x = 0;
+    node.position.y = 0;
+    node.position.z = 3;
+    node.radius = 0.5;
     bmeshAddNode(bm, &node);
 
     memset(&node, 0, sizeof(node));
-    node.position.x = -0.5;
-    node.position.y = 0.2;
-    node.position.z = 0.5;
-    node.radius = 0.1;
+    node.position.x = 1;
+    node.position.y = 0;
+    node.position.z = 2;
+    node.radius = 0.5;
     bmeshAddNode(bm, &node);
 
     memset(&edge, 0, sizeof(edge));
@@ -136,7 +138,7 @@ void Render::resizeGL(int w, int h) {
 
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
-  glFrustum(-2, 2, -1.5, 1.5, 1, 1000);
+  glFrustum(-2, 2, -1.5, 1.5, 1, 100);
 
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();