im trying to draw something but its not working
i checked that these functions are getting called
 

void myscreen_render(void* elem, float delta)
{
    struct f3_screen* s = elem;
    
    Gfx_SetVertexFormat(VERTEX_FORMAT_COLOURED);
    Gfx_BindDynamicVb(s -> vb);
    Gfx_DrawVb_IndexedTris(3);
}

void myscreen_build_mesh(void* elem)
{
    struct f3_screen* s = elem;
    struct VertexColoured vb[3];
    
    vb[0].x = 0.0f; vb[0].y = 0.0f; vb[0].z = 1.0f;
    vb[1].x = 1.0f; vb[1].y = 0.0f; vb[1].z = 1.0f;
    vb[2].x = 0.0f; vb[2].y = 1.0f; vb[2].z = 1.0f;

    vb[0].Col = PackedCol_Make(255, 0, 0, 255);
    vb[1].Col = PackedCol_Make(0, 255, 0, 255);
    vb[2].Col = PackedCol_Make(0, 0, 255, 255);
    
    Gfx_SetVertexFormat(VERTEX_FORMAT_COLOURED);
    Gfx_SetDynamicVbData(s -> vb, vb, 3);
}

void myscreen_on_context_lost(void* elem)
{
    struct f3_screen* s = elem;
    
    Gfx_DeleteDynamicVb(&s -> vb);
}

void myscreen_on_context_recreated(void* elem)
{
    struct f3_screen* s = elem;
    
    s -> vb = Gfx_CreateDynamicVb(VERTEX_FORMAT_COLOURED, 3);
    s -> maxVertices = 3;
}

 

the problem was that i needed 4 vertices

also i managed to get this