z buffer bug/problem ?

hi , i am using this to draw triangles in my project :

Code:

LPDIRECT3DDEVICE9 pd3dDev;
					pd3dDev = (LPDIRECT3DDEVICE9)draw_begin();
					if (!pd3dDev) return;
					
					// set some render and stage states
					pd3dDev->SetRenderState(D3DRS_ALPHABLENDENABLE,FALSE);
					pd3dDev->SetRenderState(D3DRS_ZENABLE,TRUE);
					pd3dDev->SetTextureStageState(0,D3DTSS_COLORARG2,D3DTA_DIFFUSE);
					pd3dDev->SetTextureStageState(0,D3DTSS_COLOROP,D3DTOP_SELECTARG2);

//.. 
					for(i=0;i<tcount;i++)
					{
						
						MD3DVERTEX v[3];
						v[0].x=vbuf[tbuf[i*3]*3];
						v[0].z=vbuf[tbuf[i*3]*3+1];
						v[0].y=vbuf[tbuf[i*3]*3+2];
						
						v[1].x=vbuf[tbuf[i*3+1]*3];
						v[1].z=vbuf[tbuf[i*3+1]*3+1];
						v[1].y=vbuf[tbuf[i*3+1]*3+2];

						v[2].x=vbuf[tbuf[i*3+2]*3];
						v[2].z=vbuf[tbuf[i*3+2]*3+1];
						v[2].y=vbuf[tbuf[i*3+2]*3+2];

	  					pd3dDev->SetFVF(MD3DFVF_D3DVERTEX);
	  					pd3dDev->DrawPrimitiveUP(D3DPT_TRIANGLELIST,1,(LPVOID)v,sizeof(MD3DVERTEX));

}

it draws fine ,except for somethings i have difficilty with:

the triangles are drawn over other draw_box3d and draw_line3d calls , this is the thing that bothers me the most ,why would this happen , i tried enabling z buffer,it happens with line drawing still.
i don't know if its me or a bug?

z buffer bug/problem ? - 10/07/15 15:19

Re: z buffer bug/problem ? - 10/17/15 21:47