OpenGL Текстурирование, без ошибок, но серый

Попытка закрасить точки местности на основе цвета текстуры (в настоящее время жестко задан для vec2 (0.5, 0.5) для целей тестирования — который должен быть светло-голубым), но все точки серые. glGetError возвращает 0 на протяжении всего процесса. Я думаю, что я неправильно выполняю процесс рендеринга или у меня проблемы с шейдерами (?)

Вершинный шейдер:

void main(){
gl_Position =  gl_ModelViewProjectionMatrix * gl_Vertex;
}

Фрагмент шейдера:

uniform sampler2D myTextureSampler;

void main(){
gl_FragColor = texture2D(myTextureSampler, vec2(0.5, 0.5));
}

Класс местности:

class Terrain
{
public:
Terrain(GLuint pProgram, char* pHeightmap, char* pTexture){
if(!LoadTerrain(pHeightmap))
{
OutputDebugString("Loading terrain failed.\n");
}
if(!LoadTexture(pTexture))
{
OutputDebugString("Loading terrain texture failed.\n");
}
mProgram = pProgram;
mTextureLocation = glGetUniformLocation(pProgram, "myTextureSampler");
};

~Terrain(){};

void Draw()
{
glEnableClientState(GL_VERTEX_ARRAY); // Uncommenting this causes me to see nothing at all

glBindBuffer(GL_ARRAY_BUFFER, mVBO);
glVertexPointer(3, GL_FLOAT, 0, 0);

glEnable( GL_TEXTURE_2D );
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, mBMP);
glProgramUniform1i(mProgram, mTextureLocation, 0);

GLenum a = glGetError();

glPointSize(5.0f);
glDrawArrays(GL_POINTS, 0, mNumberPoints);

a = glGetError();

glBindBuffer(GL_ARRAY_BUFFER, 0);

glDisable( GL_TEXTURE_2D );
glDisableClientState(GL_VERTEX_ARRAY);
}

private:
GLuint mVBO, mBMP, mUV, mTextureLocation, mProgram;
int mWidth;
int mHeight;
int mNumberPoints;

bool LoadTerrain(char* pFile)
{
/* Definitely no problem here - Vertex data is fine and rendering nice and dandy */
}

// TEXTURES MUST BE POWER OF TWO!!
bool LoadTexture(char *pFile)
{
unsigned char header[54]; // Each BMP file begins by a 54-bytes header
unsigned int dataPos;     // Position in the file where the actual data begins
unsigned int width, height;
unsigned int imageSize;
unsigned char * data;

FILE * file = fopen(pFile, "rb");
if(!file)
return false;
if(fread(header, 1, 54, file) != 54)
{
fclose(file);
return false;
}
if ( header[0]!='B' || header[1]!='M' )
{
fclose(file);
return false;
}
// Read ints from the byte array
dataPos    = *(int*)&(header[0x0A]);
imageSize  = *(int*)&(header[0x22]);
width      = *(int*)&(header[0x12]);
height     = *(int*)&(header[0x16]);
// Some BMP files are misformatted, guess missing information
if (imageSize==0)    imageSize=width*height*3; // 3 : one byte for each Red, Green and Blue component
if (dataPos==0)      dataPos=54; // The BMP header is done that way
// Create a buffer
data = new unsigned char [imageSize];

// Read the actual data from the file into the buffer
fread(data,1,imageSize,file);

//Everything is in memory now, the file can be closed
fclose(file);

// Create one OpenGL texture
glGenTextures(1, &mBMP);

// "Bind" the newly created texture : all future texture functions will modify this texture
glBindTexture(GL_TEXTURE_2D, mBMP);

// Give the image to OpenGL
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_BGR, GL_UNSIGNED_BYTE, data);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );

glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );

delete [] data;
data = 0;

return true;
}
};