Triângulo D3D

struct sVertex
{
	FLOAT x, y, z, rhw;
	DWORD dwColor;
};

VOID DrawTriangle(INT x1, INT y1, INT x2, INT y2, INT x3, INT y3, DWORD Color1, DWORD Color2, DWORD Color3, LPDIRECT3DDEVICE9 pDevice)
{
	CONST DWORD dwFVF = D3DFVF_XYZRHW | D3DFVF_DIFFUSE;
	sVertex V[3] = 
	{
		{(FLOAT)x1, (FLOAT)y1, 0.5f, 1.0f, Color1},
		{(FLOAT)x3, (FLOAT)y3, 0.5f, 1.0f, Color3},
		{(FLOAT)x2, (FLOAT)y2, 0.5f, 1.0f, Color2},
	};
	
	VOID *pVertexBuffer = NULL;
	LPDIRECT3DVERTEXBUFFER9 pBuffer = NULL;

	if(FAILED(pDevice->CreateVertexBuffer(3 * sizeof(sVertex), 0, dwFVF, D3DPOOL_DEFAULT, &pBuffer, NULL)))
		return;

	if(FAILED(pBuffer->Lock(0, sizeof(V), &pVertexBuffer, 0)))
		return;
	
	memcpy(pVertexBuffer, V, sizeof(V));
	pBuffer->Unlock();

	pDevice->SetFVF(dwFVF);
	pDevice->SetStreamSource(0, pBuffer, 0, sizeof(sVertex));
	pDevice->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 1);
}

• O que é um triângulo?
R: Um polígono com 3 lados e 3 vértices, portanto a função conta com as coordenadas de cada um dos 3 vértices que são dispostos dessa maneira

A(x1, y1) = Ponto do vértice 1
B(x2, y2) = Ponto do vértice 2
C(x3, y3) = Ponto do vértice 3

Color1 = Cor do vértice 1
Color2 = Cor do vértice 2
Color3 = Cor do vértice 3

Lado = L
Altura do Triângulo = ((L * (3 ^(1 / 2))) / 2)

A(menuX + (L / 2), menuY)
B(menuX, menuY + (L * 0.86f))
C(menuX + L, menuY + (L * 0.86f))

A(20 + 25, 25)
B(20, 25 + 43)
C(70, 25 + 43)

DrawTriangle(45, 25, 20, 68, 70, 68, D3DCOLOR_ARGB(255, 255, 000, 000), D3DCOLOR_ARGB(255, 255, 000, 000), D3DCOLOR_ARGB(255, 255, 000, 000), pDevice);