ios - OpenGL ES Texture Not Rendering -

i attempting render texture plane opengl es on iphone. have worked opengl before i'm not sure why isn't working.

when run code plane rendered black square , not textured square. believe problem may when loading texture although see no errors when run code.

hopefully spot problem , able help. in advance.

here code mesh.

// mesh loading - ( id ) init {     if ( self = [ super init ] ) {         glgenvertexarraysoes( 1, &m_vertexarray );         glbindvertexarrayoes( m_vertexarray );          glgenbuffers( 1, &m_vertexbuffer );         glbindbuffer( gl_array_buffer, m_vertexbuffer );         glbufferdata( gl_array_buffer, sizeof( g_vertices ), g_vertices, gl_static_draw );          glgenbuffers( 1, &m_texcoordbuffer );         glbindbuffer( gl_array_buffer, m_texcoordbuffer );         glbufferdata( gl_array_buffer, sizeof( g_texcoords ), g_texcoords, gl_static_draw );     }     return self; }  - ( void ) render {     glbindbuffer( gl_array_buffer, m_vertexbuffer );     glvertexattribpointer( glkvertexattribposition, 3, gl_float, gl_false, 0, ( glvoid* ) 0 );      glbindbuffer( gl_array_buffer, m_texcoordbuffer );     glvertexattribpointer( glkvertexattribtexcoord0, 2, gl_float, gl_false, 0, ( glvoid* ) 0 );      gldrawarrays( gl_triangles, 0, sizeof( g_vertices ) / sizeof( g_vertices[ 0 ] ) ); }  const glfloat g_vertices[] = {     -1.0, -1.0,  0.0,      1.0,  1.0,  0.0,     -1.0,  1.0,  0.0,      -1.0, -1.0,  0.0,      1.0, -1.0,  0.0,      1.0,  1.0,  0.0 };  const glfloat g_texcoords[] = {     0.0, 0.0,     1.0, 1.0,     0.0, 1.0,      0.0, 0.0,     1.0, 0.0,     1.0, 1.0 }; 

i need vertices , tex coords right i'm using.

next texture loading.

- ( id ) init: ( nsstring* ) filename {     if ( self = [ super init ] ) {         cgimageref spriteimage = [ uiimage imagenamed: filename ].cgimage;         if ( !spriteimage ) {             nslog( @"failed load image %@", filename );             exit( 1 );         }          size_t width = cgimagegetwidth( spriteimage );         size_t height = cgimagegetheight( spriteimage );          glubyte *spritedata = ( glubyte* ) calloc( width * height * 4, sizeof( glubyte ) );         cgcontextref spritecontext = cgbitmapcontextcreate( spritedata, width, height, 8, 4 * width, cgimagegetcolorspace( spriteimage ), kcgimagealphapremultipliedlast );          cgcontextdrawimage( spritecontext, cgrectmake( 0, 0, width, height ), spriteimage );         cgcontextrelease( spritecontext );          glgentextures( 1, &m_texture );         glbindtexture( gl_texture_2d, m_texture );          gltexparameteri( gl_texture_2d, gl_texture_min_filter, gl_nearest );         gltexparameteri( gl_texture_2d, gl_texture_mag_filter, gl_nearest );          glteximage2d( gl_texture_2d, 0, gl_rgba, ( gluint ) width, ( gluint ) height, 0, gl_rgba, gl_unsigned_byte, spritedata );          free( spritedata );     }     return self; }  - ( void ) bind {     glactivetexture( gl_texture0 );     glbindtexture( gl_texture_2d, m_texture ); } 

i used texture loading code this tutorial.

then here rendering code.

    - ( void ) glkview: ( glkview* ) view drawinrect: ( cgrect ) rect {     glclearcolor( 0.65f, 0.65f, 0.65f, 1.0f );     glclear( gl_color_buffer_bit | gl_depth_buffer_bit );      gluseprogram( m_shaderprogram );      [ m_texture bind ];      gluniform1i( uniforms[ uniform_sampler ], 0 );      glkmatrix4 mvp = glkmatrix4multiply( glkmatrix4multiply( m_projectionmatrix, m_viewmatrix ), m_modelmatrix );      gluniformmatrix4fv( uniforms[ uniform_modelviewprojection_matrix ], 1, 0, mvp.m );      glenablevertexattribarray( glkvertexattribposition );     glenablevertexattribarray( glkvertexattribtexcoord0 );      [ m_plane render ];      gldisablevertexattribarray( glkvertexattribtexcoord0 );     gldisablevertexattribarray( glkvertexattribposition ); } 

vertex shader.

attribute vec3 position; attribute vec2 texcoord;  varying lowp vec2 texcoord0;  uniform mat4 modelviewprojectionmatrix;  void main() {     texcoord0 = texcoord;     gl_position = modelviewprojectionmatrix * vec4( position, 1.0 ); } 

and lastly fragment shader.

varying lowp vec2 texcoord0;  uniform sampler2d sampler;  void main() {     gl_fragcolor = texture2d( sampler, texcoord0.st ); } 

as mentioned in comment, can check power of 2 (pot) texture. in addition, there extensions enable support nonpot (npot) textures gl_img_texture_npot, refer discussion in thread (non power of 2 textures in ios), , thread (http://aras-p.info/blog/2012/10/17/non-power-of-two-textures/).