1. GAM531 DPS931 – Week 9
OpenGL 4.3 and Direct X 11

2. BlendState <RS> Singleton Texture <RS>
Interface
Base Class RM = Resource Manager BM = Base Manager IM = Iterative Manager Sh = Shader SO = SceneObject
BlendState <RS>
Singleton
Texture <RS>
DX/GL Uniform Buffer m
Contains (m = many) RM m
Either or (only one)
DX/GL API Wrapper
BlendStateManager <RS>
Mesh <RS>
TextureManager <RS> RM
DX11 Device
GL 4.3 Device IM
ActorManager <RS> SO m m
Actor <RS> RM
ResourceController <RS>
SceneController <RS> IM
TextureSampler <RS>
MeshManager <RS>
Engine <RS>
CameraManager <RS> m RM m SO
SamplerManager <RS>
LightManager <RS> IM
Camera <RS>
VertexFormat <RS>
NodeManager <RS> BM
MaterialManager <RS> RM
VertexFormatManager<RS> RM m
ShaderManager <RS> m m SO m m m Sh Sh
Light <RS>
Node <RS> m
Material <RS>
VertexShader <RS>
FragmentShader <RS>

3. Cracking Open the Device
template <RenderSystem RS>
class Device {};
template <>
class Device<RS_DX11> { ID3D11Device* dev; … };
template <> class Device<RS_GL43> { HGLRC context; … };
DX11 Device
GL 4.3 Device
DirectX Device Object Ptr
Engine <RS>
OpenGL Context Handle

4. Same Name, Completely Different Classes
template <>
class Device<RS_DX11> {
IDXGISwapChain* swap;
ID3D11Device* dev;
ID3D11DeviceContext* con;
ID3D11RenderTargetView* backbuffer;
ID3D11DepthStencilView* depthBuffer;
bool active;
public:
Device() : swap(0), dev(0), con(0), active(false) {}
virtual ~Device();
void init(Window*);
void release();
void renderStart();
void renderEnd();
void setFullScreen(bool);
bool isActive() {return active;}
void bindPrimitive(const PrimitiveTopology&);
void draw(uint32, uint32);
void drawIndexed(uint32, uint32, uint32);
IDXGISwapChain* _exposeSwap() {return swap;}
ID3D11Device* _exposeDevice() {return dev;}
ID3D11DeviceContext* _exposeContext(); };
template<>
class Device<RS_GL43> {
HGLRC context;
HDC hdc;
HWND wh;
GLuint prim;
Window* window;
bool active;
public:
Device() : context(0), hdc(0), active(false), window(0) {}
virtual ~Device();
void init(Window*);
void release();
void renderStart();
void renderEnd();
void setFullScreen(bool);
bool isActive() {return active;}
void bindPrimitive(const PrimitiveTopology&);
void draw(uint32, uint32);
void drawIndexed(uint32, uint32, uint32); };

5. Importing DX11 and OpenGL 4.3
#include <d3d11.h>
#include <d3dx11.h>
#include <d3dx10.h>
#pragma comment (lib, "d3d11.lib")
#pragma comment (lib, "d3dx11.lib")
#pragma comment (lib, "d3dx10.lib")
#pragma comment (lib, "DXGI.lib")
(You must download the GLEW library)
#include "GL/glew.h"
#include "GL/wglew.h“

6. Biggest Difference Between GL and DX
Object Oriented
Free Floating Functions
con->OMSetRenderTargets(1, &backbuffer,
depthBuffer);
dev->CreateDepthStencilView(pDepthStencil,
&descDSV,&depthBuffer) dev->CreateTexture2D(&descDepth, NULL,
&pDepthStencil ) swap->Release();
context = wglCreateContextAttribsARB(hdc, 0,
attribs);
glEnable(GL_DEPTH_TEST);
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, w, h, format, type, data); wglDeleteContext(context);

7. Where Do We Start? Device Swap Chain Context Context
Free Floating Functions
Object Creation
Frame Buffer
Object Creation
Frame Buffer
Contains the state of the render system
Contains the state of the render system

8. Initializing a Render System
DXGI_SWAP_CHAIN_DESC d;
ZeroMemory(&d, sizeof(DXGI_SWAP_CHAIN_DESC));
d.BufferCount = 1;
d.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
d.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
d.OutputWindow = w->getWindowID();
d.SampleDesc.Count = 1;
d.SampleDesc.Quality = 0;
d.Windowed = TRUE
d.BufferDesc.Width = w->getSize().x();
d.BufferDesc.Height = w->getSize().y();
d.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
d.Flags = DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH;
D3D_FEATURE_LEVEL lev = D3D_FEATURE_LEVEL_11_0;
D3D11CreateDeviceAndSwapChain(0, D3D_DRIVER_TYPE_HARDWARE, 0, 0, &lev, 1, D3D11_SDK_VERSION, &d, &swap, &dev, 0, &con));
hdc = GetDC(win->getWindowID());
PIXELFORMATDESCRIPTOR pfd;
memset(&pfd, 0, sizeof(PIXELFORMATDESCRIPTOR));
pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DOUBLEBUFFER |
PFD_SUPPORT_OPENGL | PFD_DRAW_TO_WINDOW;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = pfd.cDepthBits = 32;
pfd.iLayerType = PFD_MAIN_PLANE;
int pixFmt = ChoosePixelFormat(hdc, &pfd);
...
auto tc = wglCreateContext(hdc); ...
glewInit();
int attribs[] = {WGL_CONTEXT_MAJOR_VERSION_ARB, 4,
WGL_CONTEXT_MINOR_VERSION_ARB, 3,
WGL_CONTEXT_FLAGS_ARB, 0, 0};
context = wglCreateContextAttribsARB(hdc, 0, attribs);
wglMakeCurrent(0,0);
wglDeleteContext(tc);
wglMakeCurrent(hdc, context);

9. Now We Need to Draw to Something
Currently On Screen
Currently Being Written To
Color buffer[1920][1080];
struct Color {float r, g, b;};
Screen may refresh before we are done rendering!

10. Setting Up The Back Buffer
ID3D11Texture2D* bb;
swap->GetBuffer(0, __uuidof(ID3D11Texture2D),
(LPVOID*)&bb));
dev->CreateRenderTargetView(bb, 0, &backbuffer));
bb->Release(); con->OMSetRenderTargets(1, &backbuffer, 0);
//Was setup sufficiently during context construction glClearColor(0.0f, 0.0f, 0.0f, 1.0f);

11. Is the pixel closer to the Camera?
Rendering With Depth
If Object A is rendered, then B, then C…
C will be drawn on top of B, which is drawn on top of A…
Is the pixel closer to the Camera?
struct Color {float r, g, b;};
Color buffer[1920][1080];
float depthBuffer[1920][1080];

12. Setting Up The Depth Buffer
ID3D11Texture2D* pDepthStencil = NULL;
D3D11_TEXTURE2D_DESC descDepth;
descDepth.Width = d.BufferDesc.Width;
descDepth.Height = d.BufferDesc.Height;
descDepth.MipLevels = descDepth.ArraySize = 1;
descDepth.Format =
DXGI_FORMAT_D24_UNORM_S8_UINT
descDepth.SampleDesc.Count = 1;
descDepth.SampleDesc.Quality = 0;
descDepth.Usage = D3D11_USAGE_DEFAULT;
descDepth.BindFlags = D3D11_BIND_DEPTH_STENCIL;
descDepth.CPUAccessFlags = 0;
descDepth.MiscFlags = 0;
dev->CreateTexture2D(&descDepth, 0, &pDepthStencil));
D3D11_DEPTH_STENCIL_DESC dsDesc;
ZeroMemory(&dsDesc, sizeof(D3D11_DEPTH_STENCIL_DESC));
dsDesc.DepthEnable = true;
dsDesc.DepthWriteMask = D3D11_DEPTH_WRITE_MASK_ALL;
dsDesc.DepthFunc = D3D11_COMPARISON_LESS_EQUAL;
dsDesc.StencilEnable = true;
dsDesc.StencilReadMask = dsDesc.StencilWriteMask = 0xFF; …
con->OMSetRenderTargets(1, &backbuffer, depthBuffer);
glEnable(GL_DEPTH_TEST);
glDepthRange(0, 1);
glDepthMask (GL_TRUE);
glDepthFunc(GL_LEQUAL);
glClearDepth(1.0);

13. Where to Render To View Port Stats: X = 300 Y = 0 Height = 800
Width = 1200

14. Setting Up The View Port
D3D11_VIEWPORT vp;
ZeroMemory(&vp, sizeof(D3D11_VIEWPORT));
vp.TopLeftX = 0;
vp.TopLeftY = 0;
vp.MinDepth = 0.0f;
vp.MaxDepth = 1.0f;
vp.Width = (float)w->getSize().x();
vp.Height = (float)w->getSize().y();
con->RSSetViewports(1, &vp);
glViewport(0,0,win->getSize().x(), win->getSize().y());

15. Rendering The World One Object At A Time

16. Render Processes //Before each new frame
con->ClearRenderTargetView(backbuffer, D3DXCOLOR(0.0f, 0.0f, 0.0f, 1.0f));
con->ClearDepthStencilView(depthBuffer, D3D11_CLEAR_DEPTH, 1.0f, 0); //Bind Primitives (more about this later) con->IASetPrimitiveTopology(_dxTranPrim(p.pte));
//Draw an object (more about this later) con->Draw(size, offset);
//Flip the back buffer (finish the frame) swap->Present(0, 0);
//Before each new frame
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
//Draw an object (more about this later) glDrawArrays(prim, offset, size);
//Flip the back buffer (finish the frame) SwapBuffers(hdc);

17. Setting Up Full Screen Mode
if (b) {
SetWindowLongPtr(wh, GWL_STYLE, WS_SYSMENU |
WS_POPUP | WS_CLIPCHILDREN | WS_CLIPSIBLINGS |
WS_VISIBLE);
SetWindowPos(wh, HWND_TOP, 0, 0,
window->getSize().x(),
window->getSize().y(), SWP_FRAMECHANGED);
DEVMODE dmScreenSettings;
memset(&dmScreenSettings,0,sizeof(dmScreenSettings));
dmScreenSettings.dmSize=sizeof(dmScreenSettings);
dmScreenSettings.dmPelsWidth = window->getSize().x();
dmScreenSettings.dmPelsHeight= window->getSize().y();
dmScreenSettings.dmBitsPerPel = 32;
dmScreenSettings.dmFields=DM_BITSPERPEL
|DM_PELSWIDTH|DM_PELSHEIGHT;
window->showWindow(true);
ShowCursor(FALSE);
} else {
SetWindowLongPtr(wh, GWL_STYLE, WS_OVERLAPPEDWINDOW |
SetWindowPos(wh,HWND_TOP,0, 0,window->getSize().x(),
ShowCursor(TRUE); }
swap->SetFullscreenState(b, 0);

18. Releasing The Render Systems
swap->SetFullscreenState(false, 0);
swap->Release();
backbuffer->Release();
depthBuffer->Release();
dev->Release();
con->Release();
wglMakeCurrent(0,0);
wglDeleteContext(context);
ReleaseDC(wh,hdc);

19. Checking For Errors auto er = dev->CreateRenderTargetView(bb, 0,
&backbuffer));
if(FAILED(er)) { //Error resolution }
auto er = glGetError();
if(er != GL_NO_ERROR) {
//Error resolution }

20. To Do Continue work on engine enhancement Read this week’s lab
Read this week’s notes
Re-implement OpenGL Device functions