在网上抄了个示例，可以加载背景色，但是不能显示三角形，要怎么改？代码在下面。

#include <SDL2/SDL.h>
#include "SDL_opengles.h"
SDL_Window*window=NULL;
SDL_Renderer*renderer=NULL;
//三维点坐标
typedef struct
{
GLfloat x;
GLfloat y;
GLfloat z;
} Vertex3D;
//创造一个点
Vertex3D Vertex3DMake(GLfloat x,GLfloat y,GLfloat z)
{
return {x,y,z};
}
//计算两点的距离
GLfloat Vertex3DCalculateDistanceBetweenVertices(Vertex3D first,Vertex3D second)
{
GLfloat deltaX=second.x-first.x;
GLfloat deltaY=second.y-first.y;
GLfloat deltaZ=second.z-first.z;
return sqrt(deltaX*deltaX+deltaY*deltaY+deltaZ*deltaZ);
}
//由三个点组合一个三角形
typedef struct
{
Vertex3D v1;
Vertex3D v2;
Vertex3D v3;
} Triangle3D;
//创造一个三角形
Triangle3D Triangle3DMake(Vertex3D first,Vertex3D second,Vertex3D third)
{
return {first,second,third};
}
int main()
{
SDL_Init (SDL_INIT_EVERYTHING );
window=SDL_CreateWindow( "SDL",0,0,960,540,SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
//renderer=SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC);
SDL_GLContext glcontext=SDL_GL_CreateContext(window);//opengl上下文
Vertex3D vertex1=Vertex3DMake(0.0,0.5,-0.9);
Vertex3D vertex2=Vertex3DMake(1.0,0.0,-3.0);
Vertex3D vertex3=Vertex3DMake(3.0,0.0,-3.0);
Triangle3D triangle=Triangle3DMake(vertex1,vertex2,vertex3);
glLoadIdentity();//加载单位矩阵
glClearColor(0.7, 0.7, 0.7, 1.0);//设置surface的清除颜色，也就是渲染到屏幕上的背景色。
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); //清除surface内容，恢复至初始状态。
glEnableClientState(GL_VERTEX_ARRAY);
//SDL_SetRenderDrawColor(renderer,0,0,0,255);
glColor4f(0.0,0.0,0.0,1.0);
glVertexPointer(3,GL_FLOAT,0,&triangle);
glDrawArrays(GL_TRIANGLES,0,9);
glDisableClientState(GL_VERTEX_ARRAY);
//SDL_RenderPresent(renderer);
SDL_GL_SwapWindow(window);
SDL_Delay(3000);
if (glcontext!=NULL)
SDL_GL_DeleteContext(glcontext);
if (renderer!=NULL)
SDL_DestroyRenderer(renderer);
if (window!=NULL)
SDL_DestroyWindow(window);
SDL_Quit();
}

我在电脑上试过没问题的，你把点换成{(1,0,0),(0,0,0),(0,1,0)}试试？