Access violation writing location, in my loop
- by numerical25
The exact error I am getting is
First-chance exception at 0x0096234a in chp2.exe: 0xC0000005: Access violation writing location 0x002b0000.
Windows has triggered a breakpoint in chp2.exe.
And the breakpoint stops here
for(DWORD i = 0; i < m; ++i)
{
//we are start at the top of z
float z = halfDepth - i*dx;
for(DWORD j = 0; j < n; ++j)
{
//to the left of us
float x = -halfWidth + j*dx;
float y = 0.0f;
vertices[i*n+j].pos = D3DXVECTOR3(x, y, z); //<----- Right here
vertices[i*n+j].color = D3DXVECTOR4(1.0f, 0.0f, 0.0f, 0.0f);
}
}
I am not sure what I am doing wrong. below is the code in its entirety
#include "MyGame.h"
//#include "CubeVector.h"
/* This code sets a projection and shows a turning cube. What has been added is the project, rotation and
a rasterizer to change the rasterization of the cube. The issue that was going on was something with the effect file
which was causing the vertices not to be rendered correctly.*/
typedef struct
{
ID3D10Effect* pEffect;
ID3D10EffectTechnique* pTechnique;
//vertex information
ID3D10Buffer* pVertexBuffer;
ID3D10Buffer* pIndicesBuffer;
ID3D10InputLayout* pVertexLayout;
UINT numVertices;
UINT numIndices;
}ModelObject;
ModelObject modelObject;
// World Matrix
D3DXMATRIX WorldMatrix;
// View Matrix
D3DXMATRIX ViewMatrix;
// Projection Matrix
D3DXMATRIX ProjectionMatrix;
ID3D10EffectMatrixVariable* pProjectionMatrixVariable = NULL;
//grid information
#define NUM_COLS 16
#define NUM_ROWS 16
#define CELL_WIDTH 32
#define CELL_HEIGHT 32
#define NUM_VERTSX (NUM_COLS + 1)
#define NUM_VERTSY (NUM_ROWS + 1)
bool MyGame::InitDirect3D()
{
if(!DX3dApp::InitDirect3D())
{
return false;
}
D3D10_RASTERIZER_DESC rastDesc;
rastDesc.FillMode = D3D10_FILL_WIREFRAME;
rastDesc.CullMode = D3D10_CULL_FRONT;
rastDesc.FrontCounterClockwise = true;
rastDesc.DepthBias = false;
rastDesc.DepthBiasClamp = 0;
rastDesc.SlopeScaledDepthBias = 0;
rastDesc.DepthClipEnable = false;
rastDesc.ScissorEnable = false;
rastDesc.MultisampleEnable = false;
rastDesc.AntialiasedLineEnable = false;
ID3D10RasterizerState *g_pRasterizerState;
mpD3DDevice->CreateRasterizerState(&rastDesc, &g_pRasterizerState);
mpD3DDevice->RSSetState(g_pRasterizerState);
// Set up the World Matrix
//The first line of code creates your identity matrix. Second line of code
//second combines your camera position, target location, and which way is up respectively
D3DXMatrixIdentity(&WorldMatrix);
D3DXMatrixLookAtLH(&ViewMatrix, new D3DXVECTOR3(200.0f, 60.0f, -20.0f), new D3DXVECTOR3(200.0f, 50.0f, 0.0f), new D3DXVECTOR3(0.0f, 1.0f, 0.0f));
// Set up the projection matrix
D3DXMatrixPerspectiveFovLH(&ProjectionMatrix, (float)D3DX_PI * 0.5f, (float)mWidth/(float)mHeight, 0.1f, 100.0f);
if(!CreateObject())
{
return false;
}
return true;
}
//These are actions that take place after the clearing of the buffer and before the present
void MyGame::GameDraw()
{
static float rotationAngle = 0.0f;
// create the rotation matrix using the rotation angle
D3DXMatrixRotationY(&WorldMatrix, rotationAngle);
rotationAngle += (float)D3DX_PI * 0.0f;
// Set the input layout
mpD3DDevice->IASetInputLayout(modelObject.pVertexLayout);
// Set vertex buffer
UINT stride = sizeof(VertexPos);
UINT offset = 0;
mpD3DDevice->IASetVertexBuffers(0, 1, &modelObject.pVertexBuffer, &stride, &offset);
mpD3DDevice->IASetIndexBuffer(modelObject.pIndicesBuffer, DXGI_FORMAT_R32_UINT, 0);
// Set primitive topology
mpD3DDevice->IASetPrimitiveTopology(D3D10_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
// Combine and send the final matrix to the shader
D3DXMATRIX finalMatrix = (WorldMatrix * ViewMatrix * ProjectionMatrix);
pProjectionMatrixVariable->SetMatrix((float*)&finalMatrix);
// make sure modelObject is valid
// Render a model object
D3D10_TECHNIQUE_DESC techniqueDescription;
modelObject.pTechnique->GetDesc(&techniqueDescription);
// Loop through the technique passes
for(UINT p=0; p < techniqueDescription.Passes; ++p)
{
modelObject.pTechnique->GetPassByIndex(p)->Apply(0);
// draw the cube using all 36 vertices and 12 triangles
mpD3DDevice->DrawIndexed(modelObject.numIndices,0,0);
}
}
//Render actually incapsulates Gamedraw, so you can call data before you actually clear the buffer or after you
//present data
void MyGame::Render()
{
DX3dApp::Render();
}
bool MyGame::CreateObject()
{
//dx will represent the width and the height of the spacing of each vector
float dx = 1;
//Below are the number of vertices
//m is the vertices of each row. n is the columns
DWORD m = 30;
DWORD n = 30;
//This get the width of the entire land
//30 - 1 = 29 rows * 1 = 29 * 0.5 = 14.5
float halfWidth = (n-1)*dx*0.5f;
float halfDepth = (m-1)*dx*0.5f;
float vertexsize = m * n;
VertexPos vertices[80];
for(DWORD i = 0; i < m; ++i)
{
//we are start at the top of z
float z = halfDepth - i*dx;
for(DWORD j = 0; j < n; ++j)
{
//to the left of us
float x = -halfWidth + j*dx;
float y = 0.0f;
vertices[i*n+j].pos = D3DXVECTOR3(x, y, z);
vertices[i*n+j].color = D3DXVECTOR4(1.0f, 0.0f, 0.0f, 0.0f);
}
}
int k = 0;
DWORD indices[540];
for(DWORD i = 0; i < n-1; ++i)
{
for(DWORD j = 0; j < n-1; ++j)
{
indices[k] = (i * n) + j;
indices[k + 1] = (i * n) + j + 1;
indices[k + 2] = (i + 1) * n + j;
indices[k + 3] = (i + 1) * n + j;
indices[k + 4] = (i * n) + j + 1;
indices[k + 5] = (i + 1) * n + j+ 1;
k += 6;
}
}
//Create Layout
D3D10_INPUT_ELEMENT_DESC layout[] = {
{"POSITION",0,DXGI_FORMAT_R32G32B32_FLOAT, 0 , 0, D3D10_INPUT_PER_VERTEX_DATA, 0},
{"COLOR",0,DXGI_FORMAT_R32G32B32A32_FLOAT, 0 , 12, D3D10_INPUT_PER_VERTEX_DATA, 0}
};
UINT numElements = (sizeof(layout)/sizeof(layout[0]));
modelObject.numVertices = sizeof(vertices)/sizeof(VertexPos);
//Create buffer desc
D3D10_BUFFER_DESC bufferDesc;
bufferDesc.Usage = D3D10_USAGE_DEFAULT;
bufferDesc.ByteWidth = sizeof(VertexPos) * modelObject.numVertices;
bufferDesc.BindFlags = D3D10_BIND_VERTEX_BUFFER;
bufferDesc.CPUAccessFlags = 0;
bufferDesc.MiscFlags = 0;
D3D10_SUBRESOURCE_DATA initData;
initData.pSysMem = vertices;
//Create the buffer
HRESULT hr = mpD3DDevice->CreateBuffer(&bufferDesc, &initData, &modelObject.pVertexBuffer);
if(FAILED(hr))
return false;
modelObject.numIndices = sizeof(indices)/sizeof(DWORD);
bufferDesc.ByteWidth = sizeof(DWORD) * modelObject.numIndices;
bufferDesc.BindFlags = D3D10_BIND_INDEX_BUFFER;
initData.pSysMem = indices;
hr = mpD3DDevice->CreateBuffer(&bufferDesc, &initData, &modelObject.pIndicesBuffer);
if(FAILED(hr))
return false;
/////////////////////////////////////////////////////////////////////////////
//Set up fx files
LPCWSTR effectFilename = L"effect.fx";
modelObject.pEffect = NULL;
hr = D3DX10CreateEffectFromFile(effectFilename,
NULL,
NULL,
"fx_4_0",
D3D10_SHADER_ENABLE_STRICTNESS,
0,
mpD3DDevice,
NULL,
NULL,
&modelObject.pEffect,
NULL,
NULL);
if(FAILED(hr))
return false;
pProjectionMatrixVariable = modelObject.pEffect->GetVariableByName("Projection")->AsMatrix();
//Dont sweat the technique. Get it!
LPCSTR effectTechniqueName = "Render";
modelObject.pTechnique = modelObject.pEffect->GetTechniqueByName(effectTechniqueName);
if(modelObject.pTechnique == NULL)
return false;
//Create Vertex layout
D3D10_PASS_DESC passDesc;
modelObject.pTechnique->GetPassByIndex(0)->GetDesc(&passDesc);
hr = mpD3DDevice->CreateInputLayout(layout, numElements,
passDesc.pIAInputSignature,
passDesc.IAInputSignatureSize,
&modelObject.pVertexLayout);
if(FAILED(hr))
return false;
return true;
}
