DirectX problems - c++

Question

I have a couple of queries regarding programming in DirectX using C++.
The first problem that I am having is that I have a texture that doesn't display on screen properly. The window is set to 800x600 when it is created and the texture is also 800x600 but when the program is loaded, only part of the texture is displayed. The code is shown below for the texture loading and drawing.
//This sets the image
helpFileTexture = new Texture(d3dDevice, L"../Resources/Help Guide.png");
//This is the draw function
helpFileTexture->Draw(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT);
//Which calls this
void Texture::Draw(long xPos, long yPos, long width, long height)
{
sprite->Begin(NULL);
RECT imageRectangle;
imageRectangle.left = xPos;
imageRectangle.top = yPos;
imageRectangle.right = imageRectangle.left + width;
imageRectangle.bottom = imageRectangle.top + height;
sprite->Draw(texture, &imageRectangle, &D3DXVECTOR3(1.0f, 1.0f, 0.0f), &D3DXVECTOR3((float)xPos, (float)yPos, 0.0f), D3DCOLOR_XRGB(255, 255, 255));
sprite->End();
}
As I said the SCREEN_WIDTH is set to 800 and the SCREEN_HEIGHT is set to 600 (which are also the same dimensions as the image). It draws from the top left as it should do but will only show part of the image. The window size was set to about 1100x1100 when the entire image could be seen. Have I done something wrong in the coding to set the image size.
The next thing is that I am having a problem hiding the cursor. I want to hide the cursor when I click the left mouse button and then have it reappear when I let go. But the cursor does not disappear. The coding for this is below.
if(input->mouseButtons.rgbButtons[0])
{
d3dDevice->ShowCursor(FALSE);
GetCursorPos(&input->mousePosition);
SetCursorPos(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2);
input->mousePosition.x -= SCREEN_WIDTH / 2;
mainCamera->UpdateYaw(input->mousePosition.x * rotationSpeed);
indexYaw += mainCamera->GetYaw();
D3DXMatrixRotationY(&viewMatrix, indexYaw);
d3dDevice->SetTransform(D3DTS_VIEW, &viewMatrix);
}
else
{
d3dDevice->ShowCursor(TRUE);
}
As you can see the cursor is suppose to disappear when the left mouse button is click for the camera control but it still shows.
The last couple of things is what is the best way to implement collision detection between objects and terrain following or can you link me to where a good place to find these would be.
I know this is a lot I have asked but any help would be great

Answer 1

The fix you implemented is not correct (the scaling one). The reason for the sizing issue is that when the texture is loaded using the D3DXLoadTextureFromFile method, DirectX changes the size of the image to the nearest power of 2 higher than the actual size. Hence the reason for it appearing larger than the screen.
So, in order to prevent it from doing this, you should use the D3DXLoadTextureFromFileEx method, and specify D3DX_DEFAULT_NONPOW2 for parameters 3 and 4. This will stop DirectX from scaling up the size of the texture. For more information on the method, refer to the MSDN page: http://msdn.microsoft.com/en-us/library/bb172802(v=vs.85).aspx
Note: Be sure to use D3DPOOL_MANAGED as the D3DPOOL option, otherwise if you use D3DPOOL_DEFAULT your models will become see through! (as I found out).