我有一个 Model2D 类,其中包含以下内容:
class Model2D
{
public: //it's private, but I'm shortening it here
unsigned char* bitmapImage;
unsigned int textureID;
int imageWidth, imageHeight;
void Load(char* bitmapFilename);
}
void Model2D::Load(char* bitmapFilename)
{
ifstream readerBMP;
readerBMP.open(bitmapFilename, ios::binary);
//I get the BMP header and fill the width, height
bitmapImage = new GLubyte[imageWidth * imageHeight * 4];
//Loop to read all the info in the BMP and fill the image array, close reader
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glGenTextures(1, &textureID);
glBindTexture(GL_TEXTURE_2D, textureID);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageWidth, imageHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, bitmapImage);
}
void Model2D::Draw()
{
glBegin(GL_QUADS);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
glBindTexture(GL_TEXTURE_2D, textureID);
float texScale = 500.0; //this is just so I don't have to resize images
glTexCoord2f(0.0, 0.0); glVertex3f(-(imageWidth / texScale), -(imageHeight / texScale), 0.0);
glTexCoord2f(0.0, 1.0); glVertex3f(-(imageWidth / texScale), (imageHeight / texScale), 0.0);
glTexCoord2f(1.0, 1.0); glVertex3f((imageWidth / texScale), (imageHeight / texScale), 0.0);
glTexCoord2f(1.0, 0.0); glVertex3f((imageWidth / texScale), -(imageHeight / texScale), 0.0);
}
在我的主循环中,我有:
Model2D spritest;
spritest.LoadFromScript("FirstBMP.bmp");
spritest.Z(-5); spritest.X(-2);
Model2D spritest2;
spritest2.LoadFromScript("SecondBMP.bmp");
spritest2.X(+2); spritest2.Z(-6);
//...
//main loop
spritest.Draw();
spritest2.Draw();
调试时似乎工作正常,位图的地址不同,OpenGL生成的纹理ID也不同,它们也被正确调用,调试时X,Y和Z位置也正确,但由于某些未知原因,spritest图像数据被sprites2覆盖。即使我不从sprites2调用 Draw() ,也会显示图像而不是spritest。
这可能是什么原因造成的?