Bullet(Cocos2dx)之优化PhysicsDraw3D，cocos2dxdraw
为了测试bullet物体的大小，匆匆写完的PhysicsDraw3D的效率低的要命，这也是为什么cocos2dx弃用了DrawPrimitives,而去使用DrawNode
DrawPrimitives每次绘制都去调用glDrawElements,假如每帧绘制10000条线段，那么就要调用10000次glDrawElements，可见效率之低。
而DrawNode采取的是批处理的方式，当drawLine的时候不是立即绘制，而是将线段的信息添加到数组里，当draw时统一调用gl的绘制函数
10000/1可不是一个小数目埃
下图使用DrawPrimitives方法
加入40个Sphere帧率就掉到40，70的帧率更是惨不忍睹
下图使用DrawNode方法
为了解决这个问题就要参照DrawNode实现一个简单的DrawNode3D
不管三七二十一，将DrawNode的头文件代码copy，删去一些不需要的，
1.修改V2F_C4B_T2F 为 V3F_C4B_T2F
2.修改Vec2为Vec3，要绘制3D
3. 保留drawPoint, drawPoints, drawLine，其他的绘制函数不要
#ifndef __DRAW_NODE_3D_H__
#define __DRAW_NODE_3D_H__
#include "cocos2d.h"
USING_NS_CC;
class DrawNode3D : public Node
{
public:
static DrawNode3D* create();
void drawPoint(const Vec3& point, const float pointSize, const Color4F &color);
void drawPoints(const Vec3 *position, unsigned int numberOfPoints, const Color4F &color);
void drawLine(const Vec3 &origin, const Vec3 &destination, const Color4F &color);
// Overrides
virtual void draw(Renderer *renderer, const Mat4 &transform, uint32_t flags) override;
void clear();
const BlendFunc& getBlendFunc() const;
void setBlendFunc(const BlendFunc &blendFunc);
void onDraw(const Mat4 &transform, uint32_t flags);
void onDrawGLLine(const Mat4 &transform, uint32_t flags);
void onDrawGLPoint(const Mat4 &transform, uint32_t flags);
CC_CONSTRUCTOR_ACCESS:
DrawNode3D();
virtual ~DrawNode3D();
virtual bool init();
protected:
void ensureCapacity(int count);
void ensureCapacityGLPoint(int count);
void ensureCapacityGLLine(int count);
GLuint_vao;
GLuint_vbo;
GLuint_vaoGLPoint;
GLuint_vboGLPoint;
GLuint_vaoGLLine;
GLuint_vboGLLine;
int_bufferCapacity;
GLsizei_bufferCount;
V3F_C4B_T2F *_buffer;
int_bufferCapacityGLPoint;
GLsizei_bufferCountGLPoint;
V3F_C4B_T2F *_bufferGLPoint;
Color4F_pointColor;
int_pointSize;
int_bufferCapacityGLLine;
GLsizei_bufferCountGLLine;
V3F_C4B_T2F *_bufferGLLine;
BlendFunc_blendFunc;
CustomCommand _customCommand;
CustomCommand _customCommandGLPoint;
CustomCommand _customCommandGLLine;
bool_dirty;
bool_dirtyGLPoint;
bool_dirtyGLLine;
private:
CC_DISALLOW_COPY_AND_ASSIGN(DrawNode3D);
};
#endif
对于DrawNode.cpp按照上面所说同样修改
要记住
glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 3, GL_FLOAT, GL_FALSE, sizeof(V3F_C4B_T2F), (GLvoid *)offsetof(V3F_C4B_T2F, vertices));
要将GLProgram::VERTEX_ATTRIB_POSITION, 2 改为 GLProgram::VERTEX_ATTRIB_POSITION, 3
因为顶点有三个元素，.cpp代码过多，请在文章最后下载源码，要注意的是绘制时开启深度测试
修改PhysicsDraw3D
删除成员变量,添加DrawNode3D* _drawNode,由于DrawNode3D继承自Node所以创建时要将其添加到父节点上，
修改create，init为如下
static PhysicsDraw3D* createWithLayer(Node* layer);
bool initWithLayer(Node* layer);
同时添加
void clearDraw();
我们知道DrawNode如果不执行clear，那么就不会清空上一帧的绘制数据
具体修改如下：
PhysicsDraw3D* PhysicsDraw3D::createWithLayer(Node* layer)
{
auto draw = new PhysicsDraw3D;
if (draw && draw->initWithLayer(layer))
{
return draw;
}
return nullptr;
}
bool PhysicsDraw3D::initWithLayer(Node* layer)
{
_drawNode = DrawNode3D::create();
layer->addChild(_drawNode);
_debugDrawMode = btIDebugDraw::DBG_MAX_DEBUG_DRAW_MODE;
return true;
}
void PhysicsDraw3D::clearDraw()
{
_drawNode->clear();
}
销毁时也要将_drawNode从Parent中移除
void PhysicsDraw3D::destroy()
{
_drawNode->removeFromParent();
delete this;
}
drawLine也就简化了
void PhysicsDraw3D::drawLine(const btVector3& from,const btVector3& to,const btVector3& color)
{
Vec3 vertices[2] = {
Vec3(from.x(), from.y(), from.z()),
Vec3(to.x(), to.y(), to.z())
};
_color.r = color.x();
_color.g = color.y();
_color.b = color.z();
_color.a = 1.f;
_drawNode->drawLine(vertices[0], vertices[1], _color);
}
PhysicsWorld3D 创建的静态函数添加
static PhysicsWorld3D* createWithDebug(Node* layer, const btVector3& gravity = btVector3(0, -10, 0));
为的就是创建调试绘制
bool PhysicsWorld3D::initWorldWithDebug(Node* layer, const btVector3& gravity)
{
if (!this->initWorld(gravity))
{
return false;
}
_debugDraw = PhysicsDraw3D::createWithLayer(layer);
_world->setDebugDrawer(_debugDraw);
return true;
}
同时删除initWorld对_debugDraw的创建，每次绘制时需要判断是否为debug
void PhysicsWorld3D::debugDraw()
{
if (_debugDraw)
{
_debugDraw->clearDraw();
_world->debugDrawWorld();
}
}
完整源码
csdn
github
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