java - OpenGL only 1 triangle is drawn -

i relatively new @ opengl lwjgl stuff, , have thoroughly checked code, 1 triangle drawn, despite me putting in coords 2. prove point, 6 points drawn gl_points.

main.scala

import org.lwjgl._ import org.lwjgl.glfw.callbacks._ import org.lwjgl.glfw.glfw._ import org.lwjgl.opengl.gl11._ import org.lwjgl.system.memoryutil._  class main {    import org.lwjgl.glfw.glfwerrorcallback   import org.lwjgl.opengl.gl    private var window = 0l    def run(): unit = {     system.out.println("version: " + version.getversion + "!")     init()     run_loop()     glfwfreecallbacks(window)     glfwdestroywindow(window)     glfwterminate()     glfwseterrorcallback(null).free()   }    private def init() = {      glfwerrorcallback.createprint(system.err).set      if (!glfwinit) throw new illegalstateexception("unable initialize glfw")      glfwdefaultwindowhints()      glfwwindowhint(glfw_visible, glfw_false)      glfwwindowhint(glfw_resizable, glfw_true)      window = glfwcreatewindow(640, 480, "window", 0, 0)     if (window == null) throw new runtimeexception("failed create glfw window")     glfwmakecontextcurrent(window)     glfwswapinterval(1)     glfwshowwindow(window)   }    def run_loop() {      gl.createcapabilities      glenable(gl_texture_2d)  val vertices: array[float] = array(    -0.5f, 0.5f, 0, //top left   0.5f, 0.5f, 0,  //top right   0.5f, -0.5f, 0, //bottom right    -0.5f, 0.5f, 0, //bottom right   -0.5f, -0.5f, 0,//bottom left   -0.5f, 0.5f, 0  //top left  )  val model: model = model(vertices)  while (!glfwwindowshouldclose(window)) {   glfwpollevents()    glclear(gl_color_buffer_bit | gl_depth_buffer_bit)    if (glfwgetkey(window, glfw_key_escape) == gl_true) { glfwsetwindowshouldclose(window, true) }    model.render()    glfwswapbuffers(window) }   } }  object main {   def main(args: array[string]): unit = {     val main: main = new main     main.run()   } } 

model.scala

import java.nio.floatbuffer  import org.lwjgl.bufferutils import org.lwjgl.opengl.gl11._ import org.lwjgl.opengl.gl15._  case class model (vertices: array[float]){    private val draw_count: int = vertices.length / 3   private val v_id: int = glgenbuffers    val buffer: floatbuffer = bufferutils.createfloatbuffer(vertices.length)   buffer.put(vertices)   buffer.flip()    glbindbuffer(gl_array_buffer, v_id)   glbufferdata(gl_array_buffer, buffer, gl_dynamic_draw)   glbindbuffer(gl_array_buffer, 0)    def render(): unit = {      glenableclientstate(gl_vertex_array)     glbindbuffer(gl_array_buffer, v_id)     glvertexpointer(3, gl_float, 0, 0)     gldrawarrays(gl_quads, 0, draw_count)     gldrawarrays(gl_points, 0, draw_count)     glbindbuffer(gl_array_buffer, 0)     gldisableclientstate(gl_vertex_array)     glpopmatrix()    }  } 

my screenshot

your vertices incorrect. if 0.5f, -0.5f bottom right, how can -0.5f, 0.5f bottom right?

val vertices: array[float] = array(     -0.5f,  0.5f, 0, // top left      0.5f,  0.5f, 0, // top right      0.5f, -0.5f, 0, // bottom right       0.5f, -0.5f, 0, // bottom right     -0.5f, -0.5f, 0, // bottom left     -0.5f,  0.5f, 0  // top left ) 

you use gl_triangle_strip along with:

val vertices: array[float] = array(     -0.5f,  0.5f, 0, // top left      0.5f,  0.5f, 0, // top right     -0.5f, -0.5f, 0, // bottom left      0.5f, -0.5f, 0, // bottom right ) 

or flip last 2 vertices , equally use gl_triangle_fan.

also note every glpushmatrix() there must glpopmatrix(). since noticed have glpopmatrix() no glpushmatrix().