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Creating 2 Triangles

Started by alop125125 Dec 13, 2016 at 12:49 AM 0 replies 1.7k views

Original Post

Dec 13, 2016 at 12:49 AM

I have been following http://www.directxtutorial.com to learn d3d and i just finished the tutorial where awe make a triangle and i dont want to move on till i have this mastered so how can i modify this code to work. Thanks, Ignore the poor practices i am still learning

#include

//include the d3d lib file

#pragma comment (lib, "d3d9.lib")

//global declarations

LPDIRECT3D9 d3d;

LPDIRECT3DDEVICE9 d3ddev;

LPDIRECT3DVERTEXBUFFER9 v_buffer;

//fucntion prototypes

void initd3d(HWND hWnd);

void render_frame();

void cleand3d();

void graphics();

LRESULT CALLBACK wndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);

#define SCREEN_HEIGHT 1920

#define SCREEN_WIDTH 1080

#define CFVF (D3DFVF_XYZRHW | D3DFVF_DIFFUSE)

struct CVERTEX

{

FLOAT x, y, z, rhw;

DWORD color;

};

int WINAPI wWinMain(HINSTANCE hInst, HINSTANCE, PWSTR lCmdLine, int nCmdShow)

{

WNDCLASS wc = {};

wc.hInstance = hInst;

wc.lpfnWndProc = wndProc;

wc.lpszClassName = "WindowClass";

wc.hCursor = LoadCursor(NULL, IDC_ARROW);

RegisterClass(&wc);

HWND hWnd = CreateWindowEx(NULL, "WindowClass", "program", WS_EX_TOPMOST| WS_POPUP, 0, 0, SCREEN_HEIGHT, SCREEN_WIDTH, NULL, NULL, hInst, NULL);

ShowWindow(hWnd, nCmdShow);

//set up d3d

initd3d(hWnd);

MSG msg = {};

while (true)

{

while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))

{

TranslateMessage(&msg);

DispatchMessage(&msg);

}

if (msg.message == WM_QUIT)

{

break;

}

//game code

render_frame();

}

cleand3d();

return msg.wParam;

}

LRESULT CALLBACK wndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)

{

switch (uMsg)

{

case WM_DESTROY:

PostQuitMessage(0);

return 0;

break;

case WM_LBUTTONDOWN:

graphics();

break;

}

return DefWindowProc(hWnd, uMsg, wParam, lParam);

}

void graphics()

{

CVERTEX tri[] =

{

{SCREEN_WIDTH / 2, 100, 0.5f, 1.0f, D3DCOLOR_XRGB(0,0,255)},

{SCREEN_WIDTH / 2 + (SCREEN_WIDTH / 3), SCREEN_HEIGHT - 100, 0.5f,1.0f, D3DCOLOR_XRGB(0,255,0)},

{SCREEN_WIDTH / 2 - (SCREEN_WIDTH / 3), SCREEN_HEIGHT - 100, 0.5f,1.0f, D3DCOLOR_XRGB(255,0,0)}

};

CVERTEX tri2[] =

{

{ 100, 100, 0.5f, 1.0f, D3DCOLOR_XRGB(0,0,255) },

{ 150, 150, 0.5f,1.0f, D3DCOLOR_XRGB(0,255,0) },

{ 50, 150, 0.5f,1.0f, D3DCOLOR_XRGB(255,0,0) }

};

d3ddev->CreateVertexBuffer(6 * sizeof(CVERTEX), 0, CFVF, D3DPOOL_MANAGED, &v_buffer, NULL);

void *pVoid;

v_buffer->Lock(0, 0, (void**)&pVoid, 0);

memcpy(pVoid, tri, sizeof(tri));

memcpy(pVoid, tri2, sizeof(tri2));

v_buffer->Unlock();

}

void render_frame()

{

d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);

d3ddev->BeginScene();

d3ddev->SetFVF(CFVF);

d3ddev->SetStreamSource(0, v_buffer, 0, sizeof(CVERTEX) * 2);

d3ddev->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 2);

d3ddev->EndScene();

d3ddev->Present(NULL, NULL, NULL, NULL);

}

void initd3d(HWND hWnd)

{

d3d = Direct3DCreate9(D3D_SDK_VERSION);

D3DPRESENT_PARAMETERS d3dpp;

ZeroMemory(&d3dpp, sizeof(d3dpp));

d3dpp.Windowed = TRUE;

d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;

d3dpp.hDeviceWindow = hWnd;

d3dpp.BackBufferFormat = D3DFMT_X8R8G8B8;

d3dpp.BackBufferWidth = SCREEN_WIDTH;

d3dpp.BackBufferHeight = SCREEN_HEIGHT;

d3d->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &d3ddev);

graphics();

}

void cleand3d()

{

v_buffer->Release();

d3d->Release();

d3ddev->Release();

}

slicer4ever

Dec 13, 2016 at 12:59 AM

can you be more specific about what issue you are having? is the code not drawing anything, or is their another issue at play?

to me, it looks like you aren't copying the second triangle to the right address, and instead are overwriting the first:

 
v_buffer->Lock(0, 0, (void**)&pVoid, 0);
 
memcpy(pVoid, tri, sizeof(tri));
memcpy(pVoid, tri2, sizeof(tri2));
v_buffer->Unlock();

should be changed to:

 
v_buffer->Lock(0, 0, (void**)&pVoid, 0);
 
memcpy(pVoid, tri, sizeof(tri));
memcpy(pVoid+sizeof(tri), tri2, sizeof(tri2));
v_buffer->Unlock();

notice that the pVoid is now offset to the next triangle slot instead of overwritting the first slot(also notice the code tags, which can be used with: [*code] and [*/code](remove the *), to better format your code.)

alternatively you can also do:

void graphics()
{
 
CVERTEX tri[] = 
{
{SCREEN_WIDTH / 2, 100, 0.5f, 1.0f, D3DCOLOR_XRGB(0,0,255)},
{SCREEN_WIDTH / 2 + (SCREEN_WIDTH / 3), SCREEN_HEIGHT - 100, 0.5f,1.0f, D3DCOLOR_XRGB(0,255,0)},
{SCREEN_WIDTH / 2 - (SCREEN_WIDTH / 3), SCREEN_HEIGHT - 100, 0.5f,1.0f, D3DCOLOR_XRGB(255,0,0)},
{ 100, 100, 0.5f, 1.0f, D3DCOLOR_XRGB(0,0,255) },
{ 150, 150, 0.5f,1.0f, D3DCOLOR_XRGB(0,255,0) },
{ 50, 150, 0.5f,1.0f, D3DCOLOR_XRGB(255,0,0) }
};
 
 
d3ddev->CreateVertexBuffer(6 * sizeof(CVERTEX), 0, CFVF, D3DPOOL_MANAGED, &v_buffer, NULL);
void *pVoid;
 
v_buffer->Lock(0, 0, (void**)&pVoid, 0);
 
memcpy(pVoid, tri, sizeof(tri));
v_buffer->Unlock();
}

this has both triangles inside the tri buffer, and is generally more efficient than copying from multiple buffers, i'd personally recommend setting up things this way instead whenever possible.

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