OpenGL ES - Draw Triangle with line only?

Question

Is there a way to draw a triangle with line only ? I think GL_TRIANGLES option make triangle filled with color.

Answer 1

Set the fill mode with glPolygonMode(face, model):

glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);

You have to set this every frame

Answer 2

Is there a way to draw a triangle with line only?

Use GL_LINES, GL_LINE_STRIP , or GL_LINE_LOOP (difference see here) with the same vertices that you use for GL_TRIANGLES.