cfont.h

Ion Team Lord Of The Rings Demo 模拟指环王的3D游戏 VS.NET编译 里面提供高级渲染算法

//////////////////////////////////////////////////////////////////
//					Code by HiperBlaster, based on NeHe's
///////////////////////////////////////////////////////////////////
//                  TODO : *Brutal* Optimization and some nice effects
//							

class CFont
{
public:
	void Init(char *file,int PixelSep);	//load the texture
	void Display(char *Text,float scale,int x,int y,int set);	//display
	~CFont();	//free mem
private:
	void LoadFontTex(char *filename);
	GLuint FontTex;		//font texture
	GLuint base;	//display list
}Standart;

//////////////////////////////////////////////////////////////////////


void CFont::Init(char *file,int PixelSep=10)
{
	LoadFontTex(file);	//load the font using alpha channel

	float	cx;
	float	cy;

	base=glGenLists(256);

	for (int loop=0; loop<256; loop++)
	{
		cx=float(loop%16)/16.0f;
		cy=float(loop/16)/16.0f;

		glNewList(base+loop,GL_COMPILE);
		glBindTexture(GL_TEXTURE_2D, FontTex);	//New | Normal Texture
			glBegin(GL_QUADS);					//New
				glTexCoord2f(cx,1-cy-0.0625f);			//New
				glVertex2i(0,0);				//New
				glTexCoord2f(cx+0.0625f,1-cy-0.0625f);		//New
				glVertex2i(16,0);				//New
				glTexCoord2f(cx+0.0625f,1-cy);			//New
				glVertex2i(16,16);				//New
				glTexCoord2f(cx,1-cy);				//New
				glVertex2i(0,16);				//New
			glEnd();						//New
		//glEnable(GL_DEPTH_TEST);	//New
		//glDisable(GL_BLEND);		//New

			glTranslated(PixelSep,0,0);
		glEndList();
	}


}

///////////////////////////////////////////////////////////////

CFont::~CFont()
{
	glDeleteLists(base,256);
	glDeleteTextures(1,&FontTex);
//	glDeleteTextures(1,&FontMask);
}


////////////////////////////////////////////////////////////////

//GLvoid glPrint(GLint x, GLint y, char *string, int set)	// Where The Printing Happens
void CFont::Display(char *string,float scale,int x,int y,int set)
{
	if (set>1)
	{
		set=1;
	}

	glEnable(GL_ALPHA_TEST);

	glAlphaFunc(GL_GREATER,0.3f);

	glDisable(GL_DEPTH_TEST);							// Disables Depth Testing

	glMatrixMode(GL_PROJECTION);						// Select The Projection Matrix
	glPushMatrix();										// Store The Projection Matrix
	glLoadIdentity();									// Reset The Projection Matrix
	glOrtho(0,640,0,480,-100,100);						// Set Up An Ortho Screen
	glMatrixMode(GL_MODELVIEW);							// Select The Modelview Matrix
	glPushMatrix();										// Store The Modelview Matrix
	glLoadIdentity();									// Reset The Modelview Matrix
	glTranslated(x,y,0);								// Position The Text (0,0 - Bottom Left)
	glScalef(scale,scale,1);
	glListBase(base-32+(128*set));						// Choose The Font Set (0 or 1)
	glCallLists(strlen(string),GL_BYTE,string);			// Write The Text To The Screen
	glMatrixMode(GL_PROJECTION);						// Select The Projection Matrix
	glPopMatrix();										// Restore The Old Projection Matrix
	glMatrixMode(GL_MODELVIEW);							// Select The Modelview Matrix
	glPopMatrix();										// Restore The Old Projection Matrix
	glEnable(GL_DEPTH_TEST);							// Enables Depth Testing
	glDisable(GL_ALPHA_TEST);

}

/////////////////////////////////////////////////////////////////////

void CFont::LoadFontTex(char *filename)
{
	FIBITMAP *Image;

	Image = FreeImage_LoadBMP(filename);

	FreeImage_ConvertTo24Bits(Image);   //for safety

	unsigned char *data;

	data = FreeImage_GetBits(Image);	//get a pointer to the data
	////////////////////////////////////////////
	//this is slow , should be asm :(
	//convert BGR to RGB for compatibility 
	unsigned int a,b;	//temp location
	unsigned int loop=0;

	while(loop!=(FreeImage_GetWidth(Image)*FreeImage_GetHeight(Image))*3)
	{
		a=data[loop];	//store B
		b=data[loop+2];	//store R

		data[loop]=b;	//put R in the first byte
		data[loop+2]=a;	//and B in the last

	loop+=3;
	}
	/////////////////////////////////////////////
	//create the alpha channel
	unsigned char *aTexture = (unsigned char*)malloc((FreeImage_GetWidth(Image)*FreeImage_GetHeight(Image))*4);
	loop=0;
	int aloop=0;

	while(loop!=FreeImage_GetWidth(Image)*FreeImage_GetHeight(Image)*3)
	{
	aTexture[aloop]=data[loop];
	aTexture[aloop+1]=data[loop+1];
	aTexture[aloop+2]=data[loop+2];
		//the comparation
		if(aTexture[aloop]+aTexture[aloop+1]+aTexture[aloop+2]==0)aTexture[aloop+3]=0;
		else aTexture[aloop+3]=255;

	loop+=3;	
	aloop+=4;
	}
	/////////////////////////////////
	//create the gl texture
		glGenTextures(1,&FontTex);
		glBindTexture(GL_TEXTURE_2D,FontTex);

		//linear

		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
		glTexImage2D(GL_TEXTURE_2D, 0, 4, FreeImage_GetWidth(Image) , FreeImage_GetHeight(Image), 0, GL_RGBA, GL_UNSIGNED_BYTE, aTexture);

	free(aTexture);
	FreeImage_Free(Image);	//frees up the memory used, it's now on gl 
	//free(data);
}