Under android with a triangle unsuccessful write native-activity drawing, expert guidance

 
static void engine_draw_frame (struct MyData * myData) {

if (myData-> display == NULL) {
/ / No display. 
return; 
} 
LOGI ("engine_draw_frame"); 
/ / =============================== Scheme1 
/ / GlClearColor (0.0f, 0.0f, 0.8f, 1.0f); 

/ / =============================== Scheme3 
unsigned short coords [] = {/ / 
0, 0, 0, / / ​​p2: (x1, y1, z1) 
1000, 0, 0, / / ​​p1: (x1, y1, z1) 
0, 500, 0 / / p3: (x1, y1, z1) 
}; 
glColor4f (0.0f, 0.3f, 0.8f, 1.0f); 
glDrawElements (GL_TRIANGLES, 3, GL_UNSIGNED_SHORT, coords); 
/ / LOGW ("% d", glGetError ()); 

static float triangleCoords [] = {/ / 
5, 500, 0, / / ​​p2: (x1, y1, z1) 
5, 1000, 0, / / ​​p1: (x1, y1, z1) 
500, 0, 0 / / p3: (x1, y1, z1) 
}; 
/ / Draw the triangle 
glColor4f (0.6f, 0.76f, 0.22f, 1.0f); 
glVertexPointer (3, GL_FLOAT, 0, triangleCoords); 
glDrawArrays (GL_TRIANGLES, 0, 3); 

/ / =============================== Scheme2 
/ / / / Just fill the screen with a color. 
/ / GlClearColor (((float) myData-> state.x) / myData-> width, myData-> state.angle, ((float) myData-> state.y) / myData-> height, 1); 

glClear (GL_COLOR_BUFFER_BIT); 
eglSwapBuffers (myData-> display, myData-> surface); 
} 

Reply:
MyData is a sample program inside the struct engine
Reply:
No answer, I'll pick points