C OpenGL glTexImage2D访问冲突

C++ OpenGL glTexImage2D Access Violation

我正在使用OpenGL(freeglut和glew)编写应用程序。

我也想要纹理，所以我对位图文件格式进行了一些研究，并为主标头和DIB标头(信息标头)编写了一个结构。

然后我开始编写加载程序。它会自动将纹理绑定到OpenGL。这是函数：

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static unsigned int ReadInteger(FILE *fp)
{
int a, b, c, d;

// Integer is 4 bytes long.
a = getc(fp);
b = getc(fp);
c = getc(fp);
d = getc(fp);

// Convert the 4 bytes to an integer.
return ((unsigned int) a) + (((unsigned int) b) << 8) +
(((unsigned int) c) << 16) + (((unsigned int) d) << 24);
}

static unsigned int ReadShort(FILE *fp)
{
int a, b;

// Short is 2 bytes long.
a = getc(fp);
b = getc(fp);

// Convert the 2 bytes to a short (int16).
return ((unsigned int) a) + (((unsigned int) b) << 8);
}

GLuint LoadBMP(const char* filename)
{
FILE* file;

// Check if a file name was provided.
if (!filename)
return 0;

// Try to open file.
fopen_s(&file, filename,"rb");

// Return if the file could not be open.
if (!file)
{
cout <<"Warning: Could not find texture '" << filename <<"'." << endl;
return 0;
}

// Read signature.
unsigned char signature[2];
fread(&signature, 2, 1, file);

// Use signature to identify a valid bitmap.
if (signature[0] != BMPSignature[0] || signature[1] != BMPSignature[1])
{
fclose(file);
return 0;
}

// Read width and height.
unsigned long width, height;
fseek(file, 16, SEEK_CUR); // After the signature we have 16bytes until the width.
width = ReadInteger(file);
height = ReadInteger(file);

// Calculate data size (we'll only support 24bpp).
unsigned long dataSize;
dataSize = width * height * 3;

// Make sure planes is 1.
if (ReadShort(file) != 1)
{
cout <<"Error: Could not load texture '" << filename <<"' (planes is not 1)." << endl;
return 0;
}

// Make sure bpp is 24.
if (ReadShort(file) != 24)
{
cout <<"Error: Could not load texture '" << filename <<"' (bits per pixel is not 24)." << endl;
return 0;
}

// Move pointer to beggining of data. (after the bpp we have 24 bytes until the data)
fseek(file, 24, SEEK_CUR);

// Allocate memory and read the image data.
unsigned char* data = new unsigned char[dataSize];

if (!data)
{
fclose(file);
cout <<"Warning: Could not allocate memory to store data of '" << filename <<"'." << endl;
return 0;
}

fread(data, dataSize, 1, file);

if (data == NULL)
{
fclose(file);
cout <<"Warning: Could no load data from '" << filename <<"'." << endl;
return 0;
}

// Close the file.
fclose(file);

// Create the texture.
GLuint texture;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);

glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); //NEAREST);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGB, width, height, GL_BGR_EXT, GL_UNSIGNED_BYTE, data);

return texture;
}

我知道正确读取了位图的数据，因为我将位图的数据输出到控制台，并与在paint中打开的图像进行了比较。

这里的问题是这一行：

1 2	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, dibheader.width, dibheader.height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);

在大多数情况下，我运行该应用程序时，该行崩溃并显示错误：

Unhandled exception at 0x008ffee9 in GunsGL.exe: 0xC0000005: Access violation reading location 0x00af7002.

这是发生错误的地方：

1	movzx ebx,byte ptr [esi+2]

这不是我的加载器的错误，因为我已经下载了其他加载器。
我使用的已下载的装载程序是NeHe的装载机。

编辑：(以上代码已更新)

我重写了装载程序，但仍然在同一行发生崩溃。而不是那次崩溃，有时我在mlock.c上崩溃了(我可以正确地回忆起相同的错误消息)：

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void __cdecl _lock (
int locknum
)
{

/*
* Create/open the lock, if necessary
*/
if ( _locktable[locknum].lock == NULL ) {

if ( !_mtinitlocknum(locknum) )
_amsg_exit( _RT_LOCK );
}

/*
* Enter the critical section.
*/

EnterCriticalSection( _locktable[locknum].lock );
}

在线：

1	EnterCriticalSection( _locktable[locknum].lock );

此外，这是应用程序不崩溃(纹理显然不正确)的其中一种情况的屏幕截图：
http://i.stack.imgur.com/4Mtso.jpg

Edit2：

使用新的工作代码更新代码。
(标记为答案的答复不包含此工作所需的全部内容，但这很重要)