direct3d 11 和 2D：将顶点的坐标作为 int 而不是 float 传递
direct3d 11 and 2D: pass coordinates of a vertex as int and not float
我的目的是编写仅使用 Direct3D 11 的 2D 工具包后端（没有其他库，如 Direct2D、SpriteBatch 或其他）。
请注意，我是第一次使用 Direct3D，目前正在学习 d3D 11。
所以现在，我可以显示我想要的颜色的三角形或矩形。
我的 C 代码的顶点结构包含 2 个用于位置的浮点数和 4 个用于颜色的无符号字符。在我的顶点着色器中，顶点结构有 2 个浮点数用于顶点位置，4 个浮点数用于颜色。
我已经说过，如果我在 D3D11_INPUT_ELEMENT_DESC 数组中使用 DXGI_FORMAT_R8G8B8A8_UNORM 作为颜色，那么颜色会自动从值 0 到 255 插入到值 0.0f 到 1.0f。当我阅读文档（DXGI Format anumeration，_UNORM 的描述）时似乎很合理：
"无符号规范化整数；在资源中被解释为无符号整数，在着色器中被解释为 [0, 1] 范围内的无符号规范化浮点值。所有 0 映射到 0.0f , 并且所有 1 都映射到 1.0f。表示从 0.0f 到 1.0f 的一系列均匀分布的浮点值。例如，2 位 UNORM 表示 0.0f、1/3、2/3 和 1.0f ."
或者至少我是这样解释这个文档的（我可能是错的）。并且三角形的颜色是正确的。
对于像素，我想做的是相同的：如果我为坐标传递一个整数（x 介于 0 和 window -1 的宽度之间，y 介于 0 和 window -1 的高度之间window - 1)，然后它被顶点着色器解释为正确的带符号归一化浮点值（x 为 -1.0f 到 1.0f，y 为 1.0f 到 -1.0f）。我在 Vertex C 结构和 D3D11_INPUT_ELEMENT_DESC 数组中尝试了几个值，但没有成功。所以我有两个问题：
- 可能吗？
- 如果不可能，在 C 代码或着色器代码（视口作为常量缓冲区）中转换坐标是否更快？从 int 到 float 的转换见下面代码中的宏 XF 和 YF。
下面是我显示一个简单三角形的完整代码，后面是顶点和像素着色器的 HLSL 代码。我用的是Direct3D的Capi。我支持Win 7和Win 10。
源代码：
/* Windows 10 */
#define _WIN32_WINNT 0x0A00
#if defined _WIN32_WINNT && _WIN32_WINNT >= 0x0A00
# define HAVE_WIN10
#endif
#include <stdio.h>
#ifndef WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
/* C API for d3d11 */
#define COBJMACROS
#include <guiddef.h>
#ifdef HAVE_WIN10
# include <dxgi1_3.h>
#else
# include <dxgi.h>
#endif
#include <d3d11.h>
#include "d3d11_vs.h"
#include "d3d11_ps.h"
/* comment for no debug informations */
#define _DEBUG
#ifdef _DEBUG
# define FCT \
do { printf(" * %s\n", __FUNCTION__); fflush(stdout); } while (0)
#else
# define FCT \
do { } while (0)
#endif
#define XF(w,x) ((float)(2 * (x) - (w)) / (float)(w))
#define YF(h,y) ((float)((h) - 2 * (y)) / (float)(h))
typedef struct Window Window;
typedef struct D3d D3d;
struct Window
{
HINSTANCE instance;
RECT rect;
HWND win;
D3d *d3d;
};
struct D3d
{
#ifdef HAVE_WIN10
IDXGIFactory2 *dxgi_factory;
IDXGISwapChain1 *dxgi_swapchain;
#else
IDXGIFactory *dxgi_factory;
IDXGISwapChain *dxgi_swapchain;
#endif
ID3D11Device *d3d_device;
ID3D11DeviceContext *d3d_device_ctx;
ID3D11RenderTargetView *d3d_render_target_view;
ID3D11InputLayout *d3d_input_layout;
ID3D11VertexShader *d3d_vertex_shader;
ID3D11PixelShader *d3d_pixel_shader;
D3D11_VIEWPORT viewport;
Window *win;
unsigned int vsync : 1;
};
typedef struct
{
FLOAT x;
FLOAT y;
BYTE r;
BYTE g;
BYTE b;
BYTE a;
} Vertex;
void d3d_resize(D3d *d3d, UINT width, UINT height);
void d3d_render(D3d *d3d);
/************************* Window *************************/
LRESULT CALLBACK
_window_procedure(HWND window,
UINT message,
WPARAM window_param,
LPARAM data_param)
{
switch (message)
{
case WM_CLOSE:
PostQuitMessage(0);
return 0;
case WM_KEYUP:
if (window_param == 'Q')
{
PostQuitMessage(0);
}
return 0;
case WM_ERASEBKGND:
/* no need to erase back */
return 1;
/* GDI notifications */
case WM_CREATE:
#ifdef _DEBUG
printf(" * WM_CREATE\n");
fflush(stdout);
#endif
return 0;
case WM_SIZE:
{
Window *win;
#ifdef _DEBUG
printf(" * WM_SIZE\n");
fflush(stdout);
#endif
win = (Window *)GetWindowLongPtr(window, GWLP_USERDATA);
d3d_resize(win->d3d,
(UINT)LOWORD(data_param), (UINT)HIWORD(data_param));
return 0;
}
case WM_PAINT:
{
#ifdef _DEBUG
printf(" * WM_PAINT\n");
fflush(stdout);
#endif
if (GetUpdateRect(window, NULL, FALSE))
{
PAINTSTRUCT ps;
Window *win;
BeginPaint(window, &ps);
win = (Window *)GetWindowLongPtr(window, GWLP_USERDATA);
d3d_render(win->d3d);
EndPaint(window, &ps);
}
return 0;
}
default:
return DefWindowProc(window, message, window_param, data_param);
}
}
Window *window_new(int x, int y, int w, int h)
{
WNDCLASS wc;
RECT r;
Window *win;
win = (Window *)calloc(1, sizeof(Window));
if (!win)
return NULL;
win->instance = GetModuleHandle(NULL);
if (!win->instance)
goto free_win;
memset(&wc, 0, sizeof(WNDCLASS));
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = _window_procedure;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = win->instance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = NULL;
wc.lpszMenuName = NULL;
wc.lpszClassName = "D3D";
if (!RegisterClass(&wc))
goto free_library;
r.left = 0;
r.top = 0;
r.right = w;
r.bottom = h;
if (!AdjustWindowRectEx(&r,
WS_OVERLAPPEDWINDOW | WS_SIZEBOX,
FALSE,
0U))
goto unregister_class;
win->win = CreateWindowEx(0U,
"D3D", "Test",
WS_OVERLAPPEDWINDOW | WS_SIZEBOX,
x, y,
r.right - r.left,
r.bottom - r.top,
NULL,
NULL, win->instance, NULL);
if (!win->win)
goto unregister_class;
return win;
unregister_class:
UnregisterClass("D2D", win->instance);
free_library:
FreeLibrary(win->instance);
free_win:
free(win);
return NULL;
}
void window_del(Window *win)
{
if (!win)
return;
DestroyWindow(win->win);
UnregisterClass("D2D", win->instance);
FreeLibrary(win->instance);
free(win);
}
void window_show(Window *win)
{
ShowWindow(win->win, SW_SHOWNORMAL);
}
/************************** D3D11 **************************/
static void d3d_refresh_rate_get(D3d *d3d, UINT *num, UINT *den)
{
DXGI_MODE_DESC *display_mode_list = NULL; /* 28 bytes */
IDXGIAdapter *dxgi_adapter;
IDXGIOutput *dxgi_output;
UINT nbr_modes;
UINT i;
HRESULT res;
*num = 0U;
*den = 1U;
if (!d3d->vsync)
return;
/* adapter of primary desktop : pass 0U */
res = IDXGIFactory_EnumAdapters(d3d->dxgi_factory, 0U, &dxgi_adapter);
if (FAILED(res))
return;
/* output of primary desktop : pass 0U */
res = IDXGIAdapter_EnumOutputs(dxgi_adapter, 0U, &dxgi_output);
if (FAILED(res))
goto release_dxgi_adapter;
/* number of mode that fit the format */
res = IDXGIOutput_GetDisplayModeList(dxgi_output,
DXGI_FORMAT_B8G8R8A8_UNORM,
DXGI_ENUM_MODES_INTERLACED,
&nbr_modes, NULL);
if (FAILED(res))
goto release_dxgi_output;
printf("display mode list : %d\n", nbr_modes);
fflush(stdout);
display_mode_list = (DXGI_MODE_DESC *)malloc(nbr_modes * sizeof(DXGI_MODE_DESC));
if (!display_mode_list)
goto release_dxgi_output;
/* fill the mode list */
res = IDXGIOutput_GetDisplayModeList(dxgi_output,
DXGI_FORMAT_B8G8R8A8_UNORM,
DXGI_ENUM_MODES_INTERLACED,
&nbr_modes, display_mode_list);
if (FAILED(res))
goto free_mode_list;
for (i = 0; i < nbr_modes; i++)
{
if ((display_mode_list[i].Width == (UINT)GetSystemMetrics(SM_CXSCREEN)) &&
(display_mode_list[i].Height == (UINT)GetSystemMetrics(SM_CYSCREEN)))
{
*num = display_mode_list[i].RefreshRate.Numerator;
*den = display_mode_list[i].RefreshRate.Denominator;
break;
}
}
#ifdef _DEBUG
{
DXGI_ADAPTER_DESC adapter_desc;
IDXGIAdapter_GetDesc(dxgi_adapter, &adapter_desc);
printf(" * video mem: %llu B, %llu MB\n",
adapter_desc.DedicatedVideoMemory,
adapter_desc.DedicatedVideoMemory / 1024 / 1024);
fflush(stdout);
wprintf(L" * description: %ls\n", adapter_desc.Description);
fflush(stdout);
}
#endif
free_mode_list:
free(display_mode_list);
release_dxgi_output:
IDXGIOutput_Release(dxgi_output);
release_dxgi_adapter:
IDXGIFactory_Release(dxgi_adapter);
}
D3d *d3d_init(Window *win, int vsync)
{
D3D11_INPUT_ELEMENT_DESC desc_ie[] =
{
{ "POSITION", 0, DXGI_FORMAT_R32G32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0 },
{ "COLOR", 0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, 2 * sizeof(float), D3D11_INPUT_PER_VERTEX_DATA, 0 }
};
#ifdef HAVE_WIN10
DXGI_SWAP_CHAIN_DESC1 desc;
DXGI_SWAP_CHAIN_FULLSCREEN_DESC desc_fs;
#else
DXGI_SWAP_CHAIN_DESC desc;
#endif
D3d *d3d;
RECT r;
HRESULT res;
UINT flags;
UINT num;
UINT den;
D3D_FEATURE_LEVEL feature_level[4];
d3d = (D3d *)calloc(1, sizeof(D3d));
if (!d3d)
return NULL;
d3d->vsync = vsync;
win->d3d = d3d;
d3d->win = win;
/* create the DXGI factory */
flags = 0;
#ifdef HAVE_WIN10
# ifdef _DEBUG
flags = DXGI_CREATE_FACTORY_DEBUG;
# endif
res = CreateDXGIFactory2(flags, &IID_IDXGIFactory2, (void **)&d3d->dxgi_factory);
#else
res = CreateDXGIFactory(&IID_IDXGIFactory, (void **)&d3d->dxgi_factory);
#endif
if (FAILED(res))
goto free_d3d;
/* single threaded for now */
flags = D3D11_CREATE_DEVICE_SINGLETHREADED |
D3D11_CREATE_DEVICE_BGRA_SUPPORT;
#ifdef HAVE_WIN10
# ifdef _DEBUG
flags |= D3D11_CREATE_DEVICE_DEBUG;
# endif
#endif
feature_level[0] = D3D_FEATURE_LEVEL_11_1;
feature_level[1] = D3D_FEATURE_LEVEL_11_0;
feature_level[2] = D3D_FEATURE_LEVEL_10_1;
feature_level[3] = D3D_FEATURE_LEVEL_10_0;
/* create device and device context with hardware support */
res = D3D11CreateDevice(NULL,
D3D_DRIVER_TYPE_HARDWARE,
NULL,
flags,
feature_level,
3U,
D3D11_SDK_VERSION,
&d3d->d3d_device,
NULL,
&d3d->d3d_device_ctx);
if (FAILED(res))
goto release_dxgi_factory2;
if (!GetClientRect(win->win, &r))
goto release_d3d_device;
/*
* create the swap chain. It needs some settings...
* the size of the internal buffers
* the image format
* the number of back buffers (>= 2 for flip model, see SwapEffect field)
*
* Settings are different in win 7 and win10
*/
d3d_refresh_rate_get(d3d, &num, &den);
#ifdef HAVE_WIN10
desc.Width = r.right - r.left;
desc.Height = r.bottom - r.top;
desc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
desc.Stereo = FALSE;
#else
desc.BufferDesc.Width = r.right - r.left;
desc.BufferDesc.Height = r.bottom - r.top;
desc.BufferDesc.RefreshRate.Numerator = num;
desc.BufferDesc.RefreshRate.Denominator = den;
desc.BufferDesc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;;
desc.BufferDesc.ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;
desc.BufferDesc.Scaling = DXGI_MODE_SCALING_UNSPECIFIED;
#endif
desc.SampleDesc.Count = 1U;
desc.SampleDesc.Quality = 0U;
desc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
desc.BufferCount = 2U;
#ifdef HAVE_WIN10
desc.Scaling = DXGI_SCALING_NONE;
#else
desc.OutputWindow = win->win;
desc.Windowed = TRUE;
#endif
desc.SwapEffect = DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL;
#ifdef HAVE_WIN10
desc.AlphaMode = DXGI_ALPHA_MODE_UNSPECIFIED;
#endif
desc.Flags = DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH;
#ifdef HAVE_WIN10
desc_fs.RefreshRate.Numerator = num;
desc_fs.RefreshRate.Denominator = den;
desc_fs.ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;
desc_fs.Scaling = DXGI_MODE_SCALING_UNSPECIFIED;
desc_fs.Windowed = TRUE;
#endif
#ifdef HAVE_WIN10
res = IDXGIFactory2_CreateSwapChainForHwnd(d3d->dxgi_factory,
(IUnknown *)d3d->d3d_device,
win->win,
&desc,
&desc_fs,
NULL,
&d3d->dxgi_swapchain);
#else
res = IDXGIFactory_CreateSwapChain(d3d->dxgi_factory,
(IUnknown *)d3d->d3d_device,
&desc,
&d3d->dxgi_swapchain);
#endif
if (FAILED(res))
goto release_d3d_device;
/* Vertex shader */
res = ID3D11Device_CreateVertexShader(d3d->d3d_device,
d3d_vertex_shader,
sizeof(d3d_vertex_shader),
NULL,
&d3d->d3d_vertex_shader);
if (FAILED(res))
{
printf(" * CreateVertexShader() failed\n");
goto release_dxgi_swapchain;
}
/* Pixel shader */
res = ID3D11Device_CreatePixelShader(d3d->d3d_device,
d3d_pixel_shader,
sizeof(d3d_pixel_shader),
NULL,
&d3d->d3d_pixel_shader);
if (FAILED(res))
{
printf(" * CreatePixelShader() failed\n");
goto release_vertex_shader;
}
/* create the input layout */
res = ID3D11Device_CreateInputLayout(d3d->d3d_device,
desc_ie,
sizeof(desc_ie) / sizeof(D3D11_INPUT_ELEMENT_DESC),
d3d_vertex_shader,
sizeof(d3d_vertex_shader),
&d3d->d3d_input_layout);
if (FAILED(res))
{
printf(" * CreateInputLayout() failed\n");
goto release_pixel_shader;
}
return d3d;
release_pixel_shader:
ID3D11PixelShader_Release(d3d->d3d_pixel_shader);
release_vertex_shader:
ID3D11VertexShader_Release(d3d->d3d_vertex_shader);
release_dxgi_swapchain:
#ifdef HAVE_WIN10
IDXGISwapChain1_SetFullscreenState(d3d->dxgi_swapchain, FALSE, NULL);
IDXGISwapChain1_Release(d3d->dxgi_swapchain);
#else
IDXGISwapChain_SetFullscreenState(d3d->dxgi_swapchain, FALSE, NULL);
IDXGISwapChain_Release(d3d->dxgi_swapchain);
#endif
release_d3d_device:
ID3D11DeviceContext_Release(d3d->d3d_device_ctx);
ID3D11Device_Release(d3d->d3d_device);
release_dxgi_factory2:
#ifdef HAVE_WIN10
IDXGIFactory2_Release(d3d->dxgi_factory);
#else
IDXGIFactory_Release(d3d->dxgi_factory);
#endif
free_d3d:
free(d3d);
return NULL;
}
void d3d_shutdown(D3d *d3d)
{
#ifdef _DEBUG
ID3D11Debug *d3d_debug;
HRESULT res;
#endif
if (!d3d)
return;
#ifdef _DEBUG
res = ID3D11Debug_QueryInterface(d3d->d3d_device, &IID_ID3D11Debug,
(void **)&d3d_debug);
#endif
ID3D11PixelShader_Release(d3d->d3d_pixel_shader);
ID3D11VertexShader_Release(d3d->d3d_vertex_shader);
ID3D11InputLayout_Release(d3d->d3d_input_layout);
ID3D11RenderTargetView_Release(d3d->d3d_render_target_view);
#ifdef HAVE_WIN10
IDXGISwapChain1_SetFullscreenState(d3d->dxgi_swapchain, FALSE, NULL);
IDXGISwapChain1_Release(d3d->dxgi_swapchain);
#else
IDXGISwapChain_SetFullscreenState(d3d->dxgi_swapchain, FALSE, NULL);
IDXGISwapChain_Release(d3d->dxgi_swapchain);
#endif
ID3D11DeviceContext_Release(d3d->d3d_device_ctx);
ID3D11Device_Release(d3d->d3d_device);
#ifdef HAVE_WIN10
IDXGIFactory2_Release(d3d->dxgi_factory);
#else
IDXGIFactory_Release(d3d->dxgi_factory);
#endif
free(d3d);
#ifdef _DEBUG
if (SUCCEEDED(res))
{
ID3D11Debug_ReportLiveDeviceObjects(d3d_debug, D3D11_RLDO_DETAIL);
ID3D11Debug_Release(d3d_debug);
}
#endif
}
void d3d_resize(D3d *d3d, UINT width, UINT height)
{
D3D11_RENDER_TARGET_VIEW_DESC desc_rtv;
ID3D11Texture2D *back_buffer;
HRESULT res;
FCT;
/* set viewport, depends on size of the window */
d3d->viewport.TopLeftX = 0.0f;
d3d->viewport.TopLeftY = 0.0f;
d3d->viewport.Width = (float)width;
d3d->viewport.Height = (float)height;
d3d->viewport.MinDepth = 0.0f;
d3d->viewport.MaxDepth = 1.0f;
/* release the render target view */
if (d3d->d3d_render_target_view)
ID3D11RenderTargetView_Release(d3d->d3d_render_target_view);
/* unset the render target view in the output merger */
ID3D11DeviceContext_OMSetRenderTargets(d3d->d3d_device_ctx,
0U, NULL, NULL);
/* resize the internal nuffers of the swapt chain to the new size */
#ifdef HAVE_WIN10
res = IDXGISwapChain1_ResizeBuffers(d3d->dxgi_swapchain,
0U, /* preserve buffer count */
width, height,
DXGI_FORMAT_UNKNOWN, /* preserve format */
0U);
#else
res = IDXGISwapChain_ResizeBuffers(d3d->dxgi_swapchain,
0U, /* preserve buffer count */
width, height,
DXGI_FORMAT_UNKNOWN, /* preserve format */
0U);
#endif
if ((res == DXGI_ERROR_DEVICE_REMOVED) ||
(res == DXGI_ERROR_DEVICE_RESET) ||
(res == DXGI_ERROR_DRIVER_INTERNAL_ERROR))
{
return;
}
if (FAILED(res))
{
printf("ResizeBuffers() failed\n");
fflush(stdout);
return;
}
/* get the internal buffer of the swap chain */
#ifdef HAVE_WIN10
res = IDXGISwapChain1_GetBuffer(d3d->dxgi_swapchain, 0,
&IID_ID3D11Texture2D,
(void **)&back_buffer);
#else
res = IDXGISwapChain_GetBuffer(d3d->dxgi_swapchain, 0,
&IID_ID3D11Texture2D,
(void **)&back_buffer);
#endif
if (FAILED(res))
{
printf("swapchain GetBuffer() failed\n");
fflush(stdout);
return;
}
ZeroMemory(&desc_rtv, sizeof(D3D11_RENDER_TARGET_VIEW_DESC));
desc_rtv.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
desc_rtv.ViewDimension = D3D11_RTV_DIMENSION_TEXTURE2D;
/* create the new render target view from this internal buffer */
res = ID3D11Device_CreateRenderTargetView(d3d->d3d_device,
(ID3D11Resource *)back_buffer,
&desc_rtv,
&d3d->d3d_render_target_view);
ID3D11Texture2D_Release(back_buffer);
}
/*** triangle ***/
typedef struct
{
Vertex vertices[3];
unsigned int indices[3];
ID3D11Buffer *vertex_buffer;
ID3D11Buffer *index_buffer; /* not useful for a single triangle */
UINT stride;
UINT offset;
UINT count;
UINT index_count;
} Triangle;
Triangle *triangle_new(D3d *d3d,
int w, int h,
int x1, int y1,
int x2, int y2,
int x3, int y3,
unsigned char r,
unsigned char g,
unsigned char b,
unsigned char a)
{
D3D11_BUFFER_DESC desc;
D3D11_SUBRESOURCE_DATA sr_data;
Triangle *t;
HRESULT res;
t = (Triangle *)malloc(sizeof(Triangle));
if (!t)
return NULL;
t->vertices[0].x = XF(w, x1);
t->vertices[0].y = YF(h, y1);
t->vertices[0].r = r;
t->vertices[0].g = g;
t->vertices[0].b = b;
t->vertices[0].a = a;
t->vertices[1].x = XF(w, x2);
t->vertices[1].y = YF(h, y2);
t->vertices[1].r = r;
t->vertices[1].g = g;
t->vertices[1].b = b;
t->vertices[1].a = a;
t->vertices[2].x = XF(w, x3);
t->vertices[2].y = YF(h, y3);
t->vertices[2].r = r;
t->vertices[2].g = g;
t->vertices[2].b = b;
t->vertices[2].a = a;
/* useful only for the rectangle later */
t->indices[0] = 0;
t->indices[1] = 1;
t->indices[2] = 2;
t->stride = sizeof(Vertex);
t->offset = 0U;
t->index_count = 3U;
desc.ByteWidth = sizeof(t->vertices);
desc.Usage = D3D11_USAGE_DYNAMIC;
desc.BindFlags = D3D11_BIND_VERTEX_BUFFER;
desc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
desc.MiscFlags = 0U;
desc.StructureByteStride = 0U;
sr_data.pSysMem = t->vertices;
sr_data.SysMemPitch = 0U;
sr_data.SysMemSlicePitch = 0U;
res = ID3D11Device_CreateBuffer(d3d->d3d_device,
&desc,
&sr_data,
&t->vertex_buffer);
if (FAILED(res))
{
free(t);
return NULL;
}
desc.ByteWidth = sizeof(t->indices);
desc.Usage = D3D11_USAGE_DYNAMIC;
desc.BindFlags = D3D11_BIND_INDEX_BUFFER;
desc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
desc.MiscFlags = 0U;
desc.StructureByteStride = 0U;
sr_data.pSysMem = t->indices;
sr_data.SysMemPitch = 0U;
sr_data.SysMemSlicePitch = 0U;
res = ID3D11Device_CreateBuffer(d3d->d3d_device,
&desc,
&sr_data,
&t->index_buffer);
if (FAILED(res))
{
free(t);
return NULL;
}
return t;
}
void triangle_free(Triangle *t)
{
if (!t)
return;
ID3D11Buffer_Release(t->index_buffer);
ID3D11Buffer_Release(t->vertex_buffer);
free(t);
}
void d3d_render(D3d *d3d)
{
#ifdef HAVE_WIN10
DXGI_PRESENT_PARAMETERS pp;
#endif
const FLOAT color[4] = { 0.10f, 0.18f, 0.24f, 1.0f };
RECT rect;
HRESULT res;
FCT;
if (!GetClientRect(d3d->win->win, &rect))
{
return;
}
/* scene */
Triangle *t;
t = triangle_new(d3d,
rect.right - rect.left,
rect.bottom - rect.top,
320, 120,
480, 360,
160, 360,
255, 255, 0, 255); /* r, g, b, a */
/* clear render target */
ID3D11DeviceContext_ClearRenderTargetView(d3d->d3d_device_ctx,
d3d->d3d_render_target_view,
color);
/* Input Assembler (IA) */
/* TRIANGLESTRIP only useful for the rectangle later */
ID3D11DeviceContext_IASetPrimitiveTopology(d3d->d3d_device_ctx,
D3D11_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP);
ID3D11DeviceContext_IASetInputLayout(d3d->d3d_device_ctx,
d3d->d3d_input_layout);
ID3D11DeviceContext_IASetVertexBuffers(d3d->d3d_device_ctx,
0,
1,
&t->vertex_buffer,
&t->stride,
&t->offset);
ID3D11DeviceContext_IASetIndexBuffer(d3d->d3d_device_ctx,
t->index_buffer,
DXGI_FORMAT_R32_UINT,
0);
/* vertex shader */
ID3D11DeviceContext_VSSetShader(d3d->d3d_device_ctx,
d3d->d3d_vertex_shader,
NULL,
0);
/* pixel shader */
ID3D11DeviceContext_PSSetShader(d3d->d3d_device_ctx,
d3d->d3d_pixel_shader,
NULL,
0);
/* set viewport in the Rasterizer Stage */
ID3D11DeviceContext_RSSetViewports(d3d->d3d_device_ctx, 1U, &d3d->viewport);
/* Output merger */
ID3D11DeviceContext_OMSetRenderTargets(d3d->d3d_device_ctx,
1U, &d3d->d3d_render_target_view,
NULL);
/* draw */
ID3D11DeviceContext_DrawIndexed(d3d->d3d_device_ctx,
t->index_count,
0, 0);
triangle_free(t);
/*
* present frame, that is flip the back buffer and the front buffer
* if no vsync, we present immediatly
*/
#ifdef HAVE_WIN10
pp.DirtyRectsCount = 0;
pp.pDirtyRects = NULL;
pp.pScrollRect = NULL;
pp.pScrollOffset = NULL;
res = IDXGISwapChain1_Present1(d3d->dxgi_swapchain,
d3d->vsync ? 1 : 0, 0, &pp);
#else
res = IDXGISwapChain_Present(d3d->dxgi_swapchain,
d3d->vsync ? 1 : 0, 0);
#endif
if (res == DXGI_ERROR_DEVICE_RESET || res == DXGI_ERROR_DEVICE_REMOVED)
{
printf("device removed or lost, need to recreate everything\n");
fflush(stdout);
}
else if (res == DXGI_STATUS_OCCLUDED)
{
printf("window is not visible, so vsync won't work. Let's sleep a bit to reduce CPU usage\n");
fflush(stdout);
}
}
int main()
{
Window *win;
D3d *d3d;
/* remove scaling on HiDPI */
#ifdef HAVE_WIN10
SetProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT_SYSTEM_AWARE);
#endif
win = window_new(100, 100, 800, 480);
if (!win)
return 1;
d3d = d3d_init(win, 0);
if (!d3d)
goto del_window;
SetWindowLongPtr(win->win, GWLP_USERDATA, (LONG_PTR)win);
window_show(win);
/* mesage loop */
while (1)
{
MSG msg;
BOOL ret;
ret = PeekMessage(&msg, NULL, 0, 0, PM_REMOVE);
if (ret)
{
do
{
if (msg.message == WM_QUIT)
goto beach;
TranslateMessage(&msg);
DispatchMessageW(&msg);
} while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE));
}
}
beach:
d3d_shutdown(d3d);
window_del(win);
return 0;
del_window:
window_del(win);
printf(" error\n");
fflush(stdout);
return 1;
}
顶点着色器：
struct vs_input
{
float2 position : POSITION;
float4 color : COLOR;
};
struct ps_input
{
float4 position : SV_POSITION;
float4 color : COLOR;
};
ps_input main(vs_input input )
{
ps_input output;
output.position = float4(input.position, 0.0f, 1.0f);
output.color = input.color;
return output;
}
像素着色器：
struct ps_input
{
float4 position : SV_POSITION;
float4 color : COLOR;
};
float4 main(ps_input input) : SV_TARGET
{
return input.color;
}
谢谢
如果你想为你的顶点使用像素坐标，你可以使用这两种格式之一：
DXGI_FORMAT_R32G32_FLOAT (same as you use right now, pixel in floating point)
DXGI_FORMAT_R32G32_UINT (pixel coordinates as int, vertex shader position input becomes uint2 position : POSITION)
如果使用float，则float转换在C端完成，如果使用UINT，则转换在vertex shader端完成。速度差异需要分析，如果顶点数量很少，我希望它可以忽略不计。
然后您可以轻松地将这些值重新映射到顶点着色器中的 -1 到 1 范围内（这非常有效），您只需要在常量缓冲区中传递反向视口大小。
所以你的顶点着色器变成：
struct vs_input
{
float2 position : POSITION;
//uint2 position : POSITION; If you use UINT
float4 color : COLOR;
};
struct ps_input
{
float4 position : SV_POSITION;
float4 color : COLOR;
};
cbuffer cbViewport : register(b0)
{
float2 inverseViewportSize;
}
ps_input main(vs_input input )
{
ps_input output;
float2 p = input.position; //if you use UINT, conversion is done here
p *= inverseViewportSize;
p *= 2.0f;
p -= 1.0f;
p.y *= -1.0f; (clip space is bottom to top, pixel is top to bottom)
output.position = float4(p, 0.0f, 1.0f);
output.color = input.color;
return output;
}
我的目的是编写仅使用 Direct3D 11 的 2D 工具包后端（没有其他库，如 Direct2D、SpriteBatch 或其他）。
请注意，我是第一次使用 Direct3D，目前正在学习 d3D 11。
所以现在，我可以显示我想要的颜色的三角形或矩形。
我的 C 代码的顶点结构包含 2 个用于位置的浮点数和 4 个用于颜色的无符号字符。在我的顶点着色器中，顶点结构有 2 个浮点数用于顶点位置，4 个浮点数用于颜色。
我已经说过，如果我在 D3D11_INPUT_ELEMENT_DESC 数组中使用 DXGI_FORMAT_R8G8B8A8_UNORM 作为颜色，那么颜色会自动从值 0 到 255 插入到值 0.0f 到 1.0f。当我阅读文档（DXGI Format anumeration，_UNORM 的描述）时似乎很合理：
"无符号规范化整数；在资源中被解释为无符号整数，在着色器中被解释为 [0, 1] 范围内的无符号规范化浮点值。所有 0 映射到 0.0f , 并且所有 1 都映射到 1.0f。表示从 0.0f 到 1.0f 的一系列均匀分布的浮点值。例如，2 位 UNORM 表示 0.0f、1/3、2/3 和 1.0f ."
或者至少我是这样解释这个文档的（我可能是错的）。并且三角形的颜色是正确的。
对于像素，我想做的是相同的：如果我为坐标传递一个整数（x 介于 0 和 window -1 的宽度之间，y 介于 0 和 window -1 的高度之间window - 1)，然后它被顶点着色器解释为正确的带符号归一化浮点值（x 为 -1.0f 到 1.0f，y 为 1.0f 到 -1.0f）。我在 Vertex C 结构和 D3D11_INPUT_ELEMENT_DESC 数组中尝试了几个值，但没有成功。所以我有两个问题：
- 可能吗？
- 如果不可能，在 C 代码或着色器代码（视口作为常量缓冲区）中转换坐标是否更快？从 int 到 float 的转换见下面代码中的宏 XF 和 YF。
下面是我显示一个简单三角形的完整代码，后面是顶点和像素着色器的 HLSL 代码。我用的是Direct3D的Capi。我支持Win 7和Win 10。
源代码：
/* Windows 10 */
#define _WIN32_WINNT 0x0A00
#if defined _WIN32_WINNT && _WIN32_WINNT >= 0x0A00
# define HAVE_WIN10
#endif
#include <stdio.h>
#ifndef WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
/* C API for d3d11 */
#define COBJMACROS
#include <guiddef.h>
#ifdef HAVE_WIN10
# include <dxgi1_3.h>
#else
# include <dxgi.h>
#endif
#include <d3d11.h>
#include "d3d11_vs.h"
#include "d3d11_ps.h"
/* comment for no debug informations */
#define _DEBUG
#ifdef _DEBUG
# define FCT \
do { printf(" * %s\n", __FUNCTION__); fflush(stdout); } while (0)
#else
# define FCT \
do { } while (0)
#endif
#define XF(w,x) ((float)(2 * (x) - (w)) / (float)(w))
#define YF(h,y) ((float)((h) - 2 * (y)) / (float)(h))
typedef struct Window Window;
typedef struct D3d D3d;
struct Window
{
HINSTANCE instance;
RECT rect;
HWND win;
D3d *d3d;
};
struct D3d
{
#ifdef HAVE_WIN10
IDXGIFactory2 *dxgi_factory;
IDXGISwapChain1 *dxgi_swapchain;
#else
IDXGIFactory *dxgi_factory;
IDXGISwapChain *dxgi_swapchain;
#endif
ID3D11Device *d3d_device;
ID3D11DeviceContext *d3d_device_ctx;
ID3D11RenderTargetView *d3d_render_target_view;
ID3D11InputLayout *d3d_input_layout;
ID3D11VertexShader *d3d_vertex_shader;
ID3D11PixelShader *d3d_pixel_shader;
D3D11_VIEWPORT viewport;
Window *win;
unsigned int vsync : 1;
};
typedef struct
{
FLOAT x;
FLOAT y;
BYTE r;
BYTE g;
BYTE b;
BYTE a;
} Vertex;
void d3d_resize(D3d *d3d, UINT width, UINT height);
void d3d_render(D3d *d3d);
/************************* Window *************************/
LRESULT CALLBACK
_window_procedure(HWND window,
UINT message,
WPARAM window_param,
LPARAM data_param)
{
switch (message)
{
case WM_CLOSE:
PostQuitMessage(0);
return 0;
case WM_KEYUP:
if (window_param == 'Q')
{
PostQuitMessage(0);
}
return 0;
case WM_ERASEBKGND:
/* no need to erase back */
return 1;
/* GDI notifications */
case WM_CREATE:
#ifdef _DEBUG
printf(" * WM_CREATE\n");
fflush(stdout);
#endif
return 0;
case WM_SIZE:
{
Window *win;
#ifdef _DEBUG
printf(" * WM_SIZE\n");
fflush(stdout);
#endif
win = (Window *)GetWindowLongPtr(window, GWLP_USERDATA);
d3d_resize(win->d3d,
(UINT)LOWORD(data_param), (UINT)HIWORD(data_param));
return 0;
}
case WM_PAINT:
{
#ifdef _DEBUG
printf(" * WM_PAINT\n");
fflush(stdout);
#endif
if (GetUpdateRect(window, NULL, FALSE))
{
PAINTSTRUCT ps;
Window *win;
BeginPaint(window, &ps);
win = (Window *)GetWindowLongPtr(window, GWLP_USERDATA);
d3d_render(win->d3d);
EndPaint(window, &ps);
}
return 0;
}
default:
return DefWindowProc(window, message, window_param, data_param);
}
}
Window *window_new(int x, int y, int w, int h)
{
WNDCLASS wc;
RECT r;
Window *win;
win = (Window *)calloc(1, sizeof(Window));
if (!win)
return NULL;
win->instance = GetModuleHandle(NULL);
if (!win->instance)
goto free_win;
memset(&wc, 0, sizeof(WNDCLASS));
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = _window_procedure;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = win->instance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = NULL;
wc.lpszMenuName = NULL;
wc.lpszClassName = "D3D";
if (!RegisterClass(&wc))
goto free_library;
r.left = 0;
r.top = 0;
r.right = w;
r.bottom = h;
if (!AdjustWindowRectEx(&r,
WS_OVERLAPPEDWINDOW | WS_SIZEBOX,
FALSE,
0U))
goto unregister_class;
win->win = CreateWindowEx(0U,
"D3D", "Test",
WS_OVERLAPPEDWINDOW | WS_SIZEBOX,
x, y,
r.right - r.left,
r.bottom - r.top,
NULL,
NULL, win->instance, NULL);
if (!win->win)
goto unregister_class;
return win;
unregister_class:
UnregisterClass("D2D", win->instance);
free_library:
FreeLibrary(win->instance);
free_win:
free(win);
return NULL;
}
void window_del(Window *win)
{
if (!win)
return;
DestroyWindow(win->win);
UnregisterClass("D2D", win->instance);
FreeLibrary(win->instance);
free(win);
}
void window_show(Window *win)
{
ShowWindow(win->win, SW_SHOWNORMAL);
}
/************************** D3D11 **************************/
static void d3d_refresh_rate_get(D3d *d3d, UINT *num, UINT *den)
{
DXGI_MODE_DESC *display_mode_list = NULL; /* 28 bytes */
IDXGIAdapter *dxgi_adapter;
IDXGIOutput *dxgi_output;
UINT nbr_modes;
UINT i;
HRESULT res;
*num = 0U;
*den = 1U;
if (!d3d->vsync)
return;
/* adapter of primary desktop : pass 0U */
res = IDXGIFactory_EnumAdapters(d3d->dxgi_factory, 0U, &dxgi_adapter);
if (FAILED(res))
return;
/* output of primary desktop : pass 0U */
res = IDXGIAdapter_EnumOutputs(dxgi_adapter, 0U, &dxgi_output);
if (FAILED(res))
goto release_dxgi_adapter;
/* number of mode that fit the format */
res = IDXGIOutput_GetDisplayModeList(dxgi_output,
DXGI_FORMAT_B8G8R8A8_UNORM,
DXGI_ENUM_MODES_INTERLACED,
&nbr_modes, NULL);
if (FAILED(res))
goto release_dxgi_output;
printf("display mode list : %d\n", nbr_modes);
fflush(stdout);
display_mode_list = (DXGI_MODE_DESC *)malloc(nbr_modes * sizeof(DXGI_MODE_DESC));
if (!display_mode_list)
goto release_dxgi_output;
/* fill the mode list */
res = IDXGIOutput_GetDisplayModeList(dxgi_output,
DXGI_FORMAT_B8G8R8A8_UNORM,
DXGI_ENUM_MODES_INTERLACED,
&nbr_modes, display_mode_list);
if (FAILED(res))
goto free_mode_list;
for (i = 0; i < nbr_modes; i++)
{
if ((display_mode_list[i].Width == (UINT)GetSystemMetrics(SM_CXSCREEN)) &&
(display_mode_list[i].Height == (UINT)GetSystemMetrics(SM_CYSCREEN)))
{
*num = display_mode_list[i].RefreshRate.Numerator;
*den = display_mode_list[i].RefreshRate.Denominator;
break;
}
}
#ifdef _DEBUG
{
DXGI_ADAPTER_DESC adapter_desc;
IDXGIAdapter_GetDesc(dxgi_adapter, &adapter_desc);
printf(" * video mem: %llu B, %llu MB\n",
adapter_desc.DedicatedVideoMemory,
adapter_desc.DedicatedVideoMemory / 1024 / 1024);
fflush(stdout);
wprintf(L" * description: %ls\n", adapter_desc.Description);
fflush(stdout);
}
#endif
free_mode_list:
free(display_mode_list);
release_dxgi_output:
IDXGIOutput_Release(dxgi_output);
release_dxgi_adapter:
IDXGIFactory_Release(dxgi_adapter);
}
D3d *d3d_init(Window *win, int vsync)
{
D3D11_INPUT_ELEMENT_DESC desc_ie[] =
{
{ "POSITION", 0, DXGI_FORMAT_R32G32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0 },
{ "COLOR", 0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, 2 * sizeof(float), D3D11_INPUT_PER_VERTEX_DATA, 0 }
};
#ifdef HAVE_WIN10
DXGI_SWAP_CHAIN_DESC1 desc;
DXGI_SWAP_CHAIN_FULLSCREEN_DESC desc_fs;
#else
DXGI_SWAP_CHAIN_DESC desc;
#endif
D3d *d3d;
RECT r;
HRESULT res;
UINT flags;
UINT num;
UINT den;
D3D_FEATURE_LEVEL feature_level[4];
d3d = (D3d *)calloc(1, sizeof(D3d));
if (!d3d)
return NULL;
d3d->vsync = vsync;
win->d3d = d3d;
d3d->win = win;
/* create the DXGI factory */
flags = 0;
#ifdef HAVE_WIN10
# ifdef _DEBUG
flags = DXGI_CREATE_FACTORY_DEBUG;
# endif
res = CreateDXGIFactory2(flags, &IID_IDXGIFactory2, (void **)&d3d->dxgi_factory);
#else
res = CreateDXGIFactory(&IID_IDXGIFactory, (void **)&d3d->dxgi_factory);
#endif
if (FAILED(res))
goto free_d3d;
/* single threaded for now */
flags = D3D11_CREATE_DEVICE_SINGLETHREADED |
D3D11_CREATE_DEVICE_BGRA_SUPPORT;
#ifdef HAVE_WIN10
# ifdef _DEBUG
flags |= D3D11_CREATE_DEVICE_DEBUG;
# endif
#endif
feature_level[0] = D3D_FEATURE_LEVEL_11_1;
feature_level[1] = D3D_FEATURE_LEVEL_11_0;
feature_level[2] = D3D_FEATURE_LEVEL_10_1;
feature_level[3] = D3D_FEATURE_LEVEL_10_0;
/* create device and device context with hardware support */
res = D3D11CreateDevice(NULL,
D3D_DRIVER_TYPE_HARDWARE,
NULL,
flags,
feature_level,
3U,
D3D11_SDK_VERSION,
&d3d->d3d_device,
NULL,
&d3d->d3d_device_ctx);
if (FAILED(res))
goto release_dxgi_factory2;
if (!GetClientRect(win->win, &r))
goto release_d3d_device;
/*
* create the swap chain. It needs some settings...
* the size of the internal buffers
* the image format
* the number of back buffers (>= 2 for flip model, see SwapEffect field)
*
* Settings are different in win 7 and win10
*/
d3d_refresh_rate_get(d3d, &num, &den);
#ifdef HAVE_WIN10
desc.Width = r.right - r.left;
desc.Height = r.bottom - r.top;
desc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
desc.Stereo = FALSE;
#else
desc.BufferDesc.Width = r.right - r.left;
desc.BufferDesc.Height = r.bottom - r.top;
desc.BufferDesc.RefreshRate.Numerator = num;
desc.BufferDesc.RefreshRate.Denominator = den;
desc.BufferDesc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;;
desc.BufferDesc.ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;
desc.BufferDesc.Scaling = DXGI_MODE_SCALING_UNSPECIFIED;
#endif
desc.SampleDesc.Count = 1U;
desc.SampleDesc.Quality = 0U;
desc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
desc.BufferCount = 2U;
#ifdef HAVE_WIN10
desc.Scaling = DXGI_SCALING_NONE;
#else
desc.OutputWindow = win->win;
desc.Windowed = TRUE;
#endif
desc.SwapEffect = DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL;
#ifdef HAVE_WIN10
desc.AlphaMode = DXGI_ALPHA_MODE_UNSPECIFIED;
#endif
desc.Flags = DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH;
#ifdef HAVE_WIN10
desc_fs.RefreshRate.Numerator = num;
desc_fs.RefreshRate.Denominator = den;
desc_fs.ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;
desc_fs.Scaling = DXGI_MODE_SCALING_UNSPECIFIED;
desc_fs.Windowed = TRUE;
#endif
#ifdef HAVE_WIN10
res = IDXGIFactory2_CreateSwapChainForHwnd(d3d->dxgi_factory,
(IUnknown *)d3d->d3d_device,
win->win,
&desc,
&desc_fs,
NULL,
&d3d->dxgi_swapchain);
#else
res = IDXGIFactory_CreateSwapChain(d3d->dxgi_factory,
(IUnknown *)d3d->d3d_device,
&desc,
&d3d->dxgi_swapchain);
#endif
if (FAILED(res))
goto release_d3d_device;
/* Vertex shader */
res = ID3D11Device_CreateVertexShader(d3d->d3d_device,
d3d_vertex_shader,
sizeof(d3d_vertex_shader),
NULL,
&d3d->d3d_vertex_shader);
if (FAILED(res))
{
printf(" * CreateVertexShader() failed\n");
goto release_dxgi_swapchain;
}
/* Pixel shader */
res = ID3D11Device_CreatePixelShader(d3d->d3d_device,
d3d_pixel_shader,
sizeof(d3d_pixel_shader),
NULL,
&d3d->d3d_pixel_shader);
if (FAILED(res))
{
printf(" * CreatePixelShader() failed\n");
goto release_vertex_shader;
}
/* create the input layout */
res = ID3D11Device_CreateInputLayout(d3d->d3d_device,
desc_ie,
sizeof(desc_ie) / sizeof(D3D11_INPUT_ELEMENT_DESC),
d3d_vertex_shader,
sizeof(d3d_vertex_shader),
&d3d->d3d_input_layout);
if (FAILED(res))
{
printf(" * CreateInputLayout() failed\n");
goto release_pixel_shader;
}
return d3d;
release_pixel_shader:
ID3D11PixelShader_Release(d3d->d3d_pixel_shader);
release_vertex_shader:
ID3D11VertexShader_Release(d3d->d3d_vertex_shader);
release_dxgi_swapchain:
#ifdef HAVE_WIN10
IDXGISwapChain1_SetFullscreenState(d3d->dxgi_swapchain, FALSE, NULL);
IDXGISwapChain1_Release(d3d->dxgi_swapchain);
#else
IDXGISwapChain_SetFullscreenState(d3d->dxgi_swapchain, FALSE, NULL);
IDXGISwapChain_Release(d3d->dxgi_swapchain);
#endif
release_d3d_device:
ID3D11DeviceContext_Release(d3d->d3d_device_ctx);
ID3D11Device_Release(d3d->d3d_device);
release_dxgi_factory2:
#ifdef HAVE_WIN10
IDXGIFactory2_Release(d3d->dxgi_factory);
#else
IDXGIFactory_Release(d3d->dxgi_factory);
#endif
free_d3d:
free(d3d);
return NULL;
}
void d3d_shutdown(D3d *d3d)
{
#ifdef _DEBUG
ID3D11Debug *d3d_debug;
HRESULT res;
#endif
if (!d3d)
return;
#ifdef _DEBUG
res = ID3D11Debug_QueryInterface(d3d->d3d_device, &IID_ID3D11Debug,
(void **)&d3d_debug);
#endif
ID3D11PixelShader_Release(d3d->d3d_pixel_shader);
ID3D11VertexShader_Release(d3d->d3d_vertex_shader);
ID3D11InputLayout_Release(d3d->d3d_input_layout);
ID3D11RenderTargetView_Release(d3d->d3d_render_target_view);
#ifdef HAVE_WIN10
IDXGISwapChain1_SetFullscreenState(d3d->dxgi_swapchain, FALSE, NULL);
IDXGISwapChain1_Release(d3d->dxgi_swapchain);
#else
IDXGISwapChain_SetFullscreenState(d3d->dxgi_swapchain, FALSE, NULL);
IDXGISwapChain_Release(d3d->dxgi_swapchain);
#endif
ID3D11DeviceContext_Release(d3d->d3d_device_ctx);
ID3D11Device_Release(d3d->d3d_device);
#ifdef HAVE_WIN10
IDXGIFactory2_Release(d3d->dxgi_factory);
#else
IDXGIFactory_Release(d3d->dxgi_factory);
#endif
free(d3d);
#ifdef _DEBUG
if (SUCCEEDED(res))
{
ID3D11Debug_ReportLiveDeviceObjects(d3d_debug, D3D11_RLDO_DETAIL);
ID3D11Debug_Release(d3d_debug);
}
#endif
}
void d3d_resize(D3d *d3d, UINT width, UINT height)
{
D3D11_RENDER_TARGET_VIEW_DESC desc_rtv;
ID3D11Texture2D *back_buffer;
HRESULT res;
FCT;
/* set viewport, depends on size of the window */
d3d->viewport.TopLeftX = 0.0f;
d3d->viewport.TopLeftY = 0.0f;
d3d->viewport.Width = (float)width;
d3d->viewport.Height = (float)height;
d3d->viewport.MinDepth = 0.0f;
d3d->viewport.MaxDepth = 1.0f;
/* release the render target view */
if (d3d->d3d_render_target_view)
ID3D11RenderTargetView_Release(d3d->d3d_render_target_view);
/* unset the render target view in the output merger */
ID3D11DeviceContext_OMSetRenderTargets(d3d->d3d_device_ctx,
0U, NULL, NULL);
/* resize the internal nuffers of the swapt chain to the new size */
#ifdef HAVE_WIN10
res = IDXGISwapChain1_ResizeBuffers(d3d->dxgi_swapchain,
0U, /* preserve buffer count */
width, height,
DXGI_FORMAT_UNKNOWN, /* preserve format */
0U);
#else
res = IDXGISwapChain_ResizeBuffers(d3d->dxgi_swapchain,
0U, /* preserve buffer count */
width, height,
DXGI_FORMAT_UNKNOWN, /* preserve format */
0U);
#endif
if ((res == DXGI_ERROR_DEVICE_REMOVED) ||
(res == DXGI_ERROR_DEVICE_RESET) ||
(res == DXGI_ERROR_DRIVER_INTERNAL_ERROR))
{
return;
}
if (FAILED(res))
{
printf("ResizeBuffers() failed\n");
fflush(stdout);
return;
}
/* get the internal buffer of the swap chain */
#ifdef HAVE_WIN10
res = IDXGISwapChain1_GetBuffer(d3d->dxgi_swapchain, 0,
&IID_ID3D11Texture2D,
(void **)&back_buffer);
#else
res = IDXGISwapChain_GetBuffer(d3d->dxgi_swapchain, 0,
&IID_ID3D11Texture2D,
(void **)&back_buffer);
#endif
if (FAILED(res))
{
printf("swapchain GetBuffer() failed\n");
fflush(stdout);
return;
}
ZeroMemory(&desc_rtv, sizeof(D3D11_RENDER_TARGET_VIEW_DESC));
desc_rtv.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
desc_rtv.ViewDimension = D3D11_RTV_DIMENSION_TEXTURE2D;
/* create the new render target view from this internal buffer */
res = ID3D11Device_CreateRenderTargetView(d3d->d3d_device,
(ID3D11Resource *)back_buffer,
&desc_rtv,
&d3d->d3d_render_target_view);
ID3D11Texture2D_Release(back_buffer);
}
/*** triangle ***/
typedef struct
{
Vertex vertices[3];
unsigned int indices[3];
ID3D11Buffer *vertex_buffer;
ID3D11Buffer *index_buffer; /* not useful for a single triangle */
UINT stride;
UINT offset;
UINT count;
UINT index_count;
} Triangle;
Triangle *triangle_new(D3d *d3d,
int w, int h,
int x1, int y1,
int x2, int y2,
int x3, int y3,
unsigned char r,
unsigned char g,
unsigned char b,
unsigned char a)
{
D3D11_BUFFER_DESC desc;
D3D11_SUBRESOURCE_DATA sr_data;
Triangle *t;
HRESULT res;
t = (Triangle *)malloc(sizeof(Triangle));
if (!t)
return NULL;
t->vertices[0].x = XF(w, x1);
t->vertices[0].y = YF(h, y1);
t->vertices[0].r = r;
t->vertices[0].g = g;
t->vertices[0].b = b;
t->vertices[0].a = a;
t->vertices[1].x = XF(w, x2);
t->vertices[1].y = YF(h, y2);
t->vertices[1].r = r;
t->vertices[1].g = g;
t->vertices[1].b = b;
t->vertices[1].a = a;
t->vertices[2].x = XF(w, x3);
t->vertices[2].y = YF(h, y3);
t->vertices[2].r = r;
t->vertices[2].g = g;
t->vertices[2].b = b;
t->vertices[2].a = a;
/* useful only for the rectangle later */
t->indices[0] = 0;
t->indices[1] = 1;
t->indices[2] = 2;
t->stride = sizeof(Vertex);
t->offset = 0U;
t->index_count = 3U;
desc.ByteWidth = sizeof(t->vertices);
desc.Usage = D3D11_USAGE_DYNAMIC;
desc.BindFlags = D3D11_BIND_VERTEX_BUFFER;
desc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
desc.MiscFlags = 0U;
desc.StructureByteStride = 0U;
sr_data.pSysMem = t->vertices;
sr_data.SysMemPitch = 0U;
sr_data.SysMemSlicePitch = 0U;
res = ID3D11Device_CreateBuffer(d3d->d3d_device,
&desc,
&sr_data,
&t->vertex_buffer);
if (FAILED(res))
{
free(t);
return NULL;
}
desc.ByteWidth = sizeof(t->indices);
desc.Usage = D3D11_USAGE_DYNAMIC;
desc.BindFlags = D3D11_BIND_INDEX_BUFFER;
desc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
desc.MiscFlags = 0U;
desc.StructureByteStride = 0U;
sr_data.pSysMem = t->indices;
sr_data.SysMemPitch = 0U;
sr_data.SysMemSlicePitch = 0U;
res = ID3D11Device_CreateBuffer(d3d->d3d_device,
&desc,
&sr_data,
&t->index_buffer);
if (FAILED(res))
{
free(t);
return NULL;
}
return t;
}
void triangle_free(Triangle *t)
{
if (!t)
return;
ID3D11Buffer_Release(t->index_buffer);
ID3D11Buffer_Release(t->vertex_buffer);
free(t);
}
void d3d_render(D3d *d3d)
{
#ifdef HAVE_WIN10
DXGI_PRESENT_PARAMETERS pp;
#endif
const FLOAT color[4] = { 0.10f, 0.18f, 0.24f, 1.0f };
RECT rect;
HRESULT res;
FCT;
if (!GetClientRect(d3d->win->win, &rect))
{
return;
}
/* scene */
Triangle *t;
t = triangle_new(d3d,
rect.right - rect.left,
rect.bottom - rect.top,
320, 120,
480, 360,
160, 360,
255, 255, 0, 255); /* r, g, b, a */
/* clear render target */
ID3D11DeviceContext_ClearRenderTargetView(d3d->d3d_device_ctx,
d3d->d3d_render_target_view,
color);
/* Input Assembler (IA) */
/* TRIANGLESTRIP only useful for the rectangle later */
ID3D11DeviceContext_IASetPrimitiveTopology(d3d->d3d_device_ctx,
D3D11_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP);
ID3D11DeviceContext_IASetInputLayout(d3d->d3d_device_ctx,
d3d->d3d_input_layout);
ID3D11DeviceContext_IASetVertexBuffers(d3d->d3d_device_ctx,
0,
1,
&t->vertex_buffer,
&t->stride,
&t->offset);
ID3D11DeviceContext_IASetIndexBuffer(d3d->d3d_device_ctx,
t->index_buffer,
DXGI_FORMAT_R32_UINT,
0);
/* vertex shader */
ID3D11DeviceContext_VSSetShader(d3d->d3d_device_ctx,
d3d->d3d_vertex_shader,
NULL,
0);
/* pixel shader */
ID3D11DeviceContext_PSSetShader(d3d->d3d_device_ctx,
d3d->d3d_pixel_shader,
NULL,
0);
/* set viewport in the Rasterizer Stage */
ID3D11DeviceContext_RSSetViewports(d3d->d3d_device_ctx, 1U, &d3d->viewport);
/* Output merger */
ID3D11DeviceContext_OMSetRenderTargets(d3d->d3d_device_ctx,
1U, &d3d->d3d_render_target_view,
NULL);
/* draw */
ID3D11DeviceContext_DrawIndexed(d3d->d3d_device_ctx,
t->index_count,
0, 0);
triangle_free(t);
/*
* present frame, that is flip the back buffer and the front buffer
* if no vsync, we present immediatly
*/
#ifdef HAVE_WIN10
pp.DirtyRectsCount = 0;
pp.pDirtyRects = NULL;
pp.pScrollRect = NULL;
pp.pScrollOffset = NULL;
res = IDXGISwapChain1_Present1(d3d->dxgi_swapchain,
d3d->vsync ? 1 : 0, 0, &pp);
#else
res = IDXGISwapChain_Present(d3d->dxgi_swapchain,
d3d->vsync ? 1 : 0, 0);
#endif
if (res == DXGI_ERROR_DEVICE_RESET || res == DXGI_ERROR_DEVICE_REMOVED)
{
printf("device removed or lost, need to recreate everything\n");
fflush(stdout);
}
else if (res == DXGI_STATUS_OCCLUDED)
{
printf("window is not visible, so vsync won't work. Let's sleep a bit to reduce CPU usage\n");
fflush(stdout);
}
}
int main()
{
Window *win;
D3d *d3d;
/* remove scaling on HiDPI */
#ifdef HAVE_WIN10
SetProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT_SYSTEM_AWARE);
#endif
win = window_new(100, 100, 800, 480);
if (!win)
return 1;
d3d = d3d_init(win, 0);
if (!d3d)
goto del_window;
SetWindowLongPtr(win->win, GWLP_USERDATA, (LONG_PTR)win);
window_show(win);
/* mesage loop */
while (1)
{
MSG msg;
BOOL ret;
ret = PeekMessage(&msg, NULL, 0, 0, PM_REMOVE);
if (ret)
{
do
{
if (msg.message == WM_QUIT)
goto beach;
TranslateMessage(&msg);
DispatchMessageW(&msg);
} while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE));
}
}
beach:
d3d_shutdown(d3d);
window_del(win);
return 0;
del_window:
window_del(win);
printf(" error\n");
fflush(stdout);
return 1;
}
顶点着色器：
struct vs_input
{
float2 position : POSITION;
float4 color : COLOR;
};
struct ps_input
{
float4 position : SV_POSITION;
float4 color : COLOR;
};
ps_input main(vs_input input )
{
ps_input output;
output.position = float4(input.position, 0.0f, 1.0f);
output.color = input.color;
return output;
}
像素着色器：
struct ps_input
{
float4 position : SV_POSITION;
float4 color : COLOR;
};
float4 main(ps_input input) : SV_TARGET
{
return input.color;
}
谢谢
如果你想为你的顶点使用像素坐标，你可以使用这两种格式之一：
DXGI_FORMAT_R32G32_FLOAT (same as you use right now, pixel in floating point)
DXGI_FORMAT_R32G32_UINT (pixel coordinates as int, vertex shader position input becomes uint2 position : POSITION)
如果使用float，则float转换在C端完成，如果使用UINT，则转换在vertex shader端完成。速度差异需要分析，如果顶点数量很少，我希望它可以忽略不计。
然后您可以轻松地将这些值重新映射到顶点着色器中的 -1 到 1 范围内（这非常有效），您只需要在常量缓冲区中传递反向视口大小。
所以你的顶点着色器变成：
struct vs_input
{
float2 position : POSITION;
//uint2 position : POSITION; If you use UINT
float4 color : COLOR;
};
struct ps_input
{
float4 position : SV_POSITION;
float4 color : COLOR;
};
cbuffer cbViewport : register(b0)
{
float2 inverseViewportSize;
}
ps_input main(vs_input input )
{
ps_input output;
float2 p = input.position; //if you use UINT, conversion is done here
p *= inverseViewportSize;
p *= 2.0f;
p -= 1.0f;
p.y *= -1.0f; (clip space is bottom to top, pixel is top to bottom)
output.position = float4(p, 0.0f, 1.0f);
output.color = input.color;
return output;
}