Examples: DirectX9: Wastefully use a RGBA8 texture for the font texture to make compability more evident with user's textures (#521)

examples/directx9_example/imgui_impl_dx9.cpp

@@ -94,8 +94,9 @@ void ImGui_ImplDX9_RenderDrawLists(ImDrawData* draw_data)
     g_pd3dDevice->SetRenderState( D3DRS_SRCBLEND, D3DBLEND_SRCALPHA );
     g_pd3dDevice->SetRenderState( D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA );
     g_pd3dDevice->SetRenderState( D3DRS_SCISSORTESTENABLE, true );
-    g_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLOROP, D3DTOP_SELECTARG1 );
-    g_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLORARG1, D3DTA_DIFFUSE );
+    g_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLOROP, D3DTOP_MODULATE );
+    g_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLORARG1, D3DTA_TEXTURE );   
+    g_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLORARG2, D3DTA_DIFFUSE );   
     g_pd3dDevice->SetTextureStageState( 0, D3DTSS_ALPHAOP, D3DTOP_MODULATE );
     g_pd3dDevice->SetTextureStageState( 0, D3DTSS_ALPHAARG1, D3DTA_TEXTURE );
     g_pd3dDevice->SetTextureStageState( 0, D3DTSS_ALPHAARG2, D3DTA_DIFFUSE );
@@ -234,11 +235,11 @@ static bool ImGui_ImplDX9_CreateFontsTexture()
     ImGuiIO& io = ImGui::GetIO();
     unsigned char* pixels;
     int width, height, bytes_per_pixel;
-    io.Fonts->GetTexDataAsAlpha8(&pixels, &width, &height, &bytes_per_pixel);
+    io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height, &bytes_per_pixel);
 
     // Upload texture to graphics system
     g_FontTexture = NULL;
-    if (D3DXCreateTexture(g_pd3dDevice, width, height, 1, D3DUSAGE_DYNAMIC, D3DFMT_A8, D3DPOOL_DEFAULT, &g_FontTexture) < 0)
+    if (D3DXCreateTexture(g_pd3dDevice, width, height, 1, D3DUSAGE_DYNAMIC, D3DFMT_A8B8G8R8, D3DPOOL_DEFAULT, &g_FontTexture) < 0)
         return false;
     D3DLOCKED_RECT tex_locked_rect;
     if (g_FontTexture->LockRect(0, &tex_locked_rect, NULL, 0) != D3D_OK)