lesson22.cpp

关于OpenGL的实例教程源代码

		s[0]=0.0f;		s[1]=0.0f;		s[2]=-1.0f;
		t[0]=0.0f;		t[1]=1.0f;		t[2]=0.0f;
		for (i=16; i<20; i++) {	
			c[0]=data[5*i+2];		
			c[1]=data[5*i+3];
			c[2]=data[5*i+4];
			SetUpBumps(n,c,l,s,t);
			glTexCoord2f(data[5*i]+c[0], data[5*i+1]+c[1]); 
			glVertex3f(data[5*i+2], data[5*i+3], data[5*i+4]);
		}
		// Left Face
		n[0]=-1.0f;		n[1]=0.0f;		n[2]=0.0f;		
		s[0]=0.0f;		s[1]=0.0f;		s[2]=1.0f;
		t[0]=0.0f;		t[1]=1.0f;		t[2]=0.0f;
		for (i=20; i<24; i++) {	
			c[0]=data[5*i+2];		
			c[1]=data[5*i+3];
			c[2]=data[5*i+4];
			SetUpBumps(n,c,l,s,t);
			glTexCoord2f(data[5*i]+c[0], data[5*i+1]+c[1]); 
			glVertex3f(data[5*i+2], data[5*i+3], data[5*i+4]);
		}		
	glEnd();
	
/* PASS#3:	Use Texture "Base"
			Blend GL_DST_COLOR To GL_SRC_COLOR (Multiplies By 2)
			Lighting Enabled
			No Offset Texture-Coordinates
			*/
	if (!emboss) {
		glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
		glBindTexture(GL_TEXTURE_2D,texture[filter]);
		glBlendFunc(GL_DST_COLOR,GL_SRC_COLOR);	
		glEnable(GL_LIGHTING);
		doCube();
	}

	xrot+=xspeed;
	yrot+=yspeed;
	if (xrot>360.0f) xrot-=360.0f;
	if (xrot<0.0f) xrot+=360.0f;
	if (yrot>360.0f) yrot-=360.0f;
	if (yrot<0.0f) yrot+=360.0f;

/*	LAST PASS:	Do The Logos! */
	doLogo();
	
	return true;										// Keep Going
}

bool doMesh2TexelUnits(void) {
	
	GLfloat c[4]={0.0f,0.0f,0.0f,1.0f};					// holds current vertex
	GLfloat n[4]={0.0f,0.0f,0.0f,1.0f};					// normalized normal of current surface		
	GLfloat s[4]={0.0f,0.0f,0.0f,1.0f};					// s-texture coordinate direction, normalized
	GLfloat t[4]={0.0f,0.0f,0.0f,1.0f};					// t-texture coordinate direction, normalized
	GLfloat l[4];										// holds our lightposition to be transformed into object space
	GLfloat Minv[16];									// holds the inverted modelview matrix to do so.
	int i;								

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	// Clear The Screen And The Depth Buffer
		
	// Build Inverse Modelview Matrix First. This Substitutes One Push/Pop With One glLoadIdentity();
	// Simply Build It By Doing All Transformations Negated And In Reverse Order.
	glLoadIdentity();								
	glRotatef(-yrot,0.0f,1.0f,0.0f);
	glRotatef(-xrot,1.0f,0.0f,0.0f);
	glTranslatef(0.0f,0.0f,-z);
	glGetFloatv(GL_MODELVIEW_MATRIX,Minv);
	glLoadIdentity();
	glTranslatef(0.0f,0.0f,z);

	glRotatef(xrot,1.0f,0.0f,0.0f);
	glRotatef(yrot,0.0f,1.0f,0.0f);	

	// Transform The Lightposition Into Object Coordinates:
	l[0]=LightPosition[0];
	l[1]=LightPosition[1];
	l[2]=LightPosition[2];
	l[3]=1.0f;											// Homogenous Coordinate
	VMatMult(Minv,l);
		
/*	PASS#1: Texel-Unit 0:	Use Texture "Bump"
							No Blend
							No Lighting
							No Offset Texture-Coordinates 
							Texture-Operation "Replace"
			Texel-Unit 1:	Use Texture "Invbump"
							No Lighting
							Offset Texture Coordinates 
							Texture-Operation "Replace"
*/
	// TEXTURE-UNIT #0		
	glActiveTextureARB(GL_TEXTURE0_ARB);
	glEnable(GL_TEXTURE_2D);
	glBindTexture(GL_TEXTURE_2D, bump[filter]);
	glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_EXT);
	glTexEnvf (GL_TEXTURE_ENV, GL_COMBINE_RGB_EXT, GL_REPLACE);	
	// TEXTURE-UNIT #1:
	glActiveTextureARB(GL_TEXTURE1_ARB);
	glEnable(GL_TEXTURE_2D);
	glBindTexture(GL_TEXTURE_2D, invbump[filter]);
	glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_EXT);
	glTexEnvf (GL_TEXTURE_ENV, GL_COMBINE_RGB_EXT, GL_ADD);
	// General Switches:
	glDisable(GL_BLEND);
	glDisable(GL_LIGHTING);	
	glBegin(GL_QUADS);	
		// Front Face	
		n[0]=0.0f;		n[1]=0.0f;		n[2]=1.0f;			
		s[0]=1.0f;		s[1]=0.0f;		s[2]=0.0f;
		t[0]=0.0f;		t[1]=1.0f;		t[2]=0.0f;
		for (i=0; i<4; i++) {	
			c[0]=data[5*i+2];		
			c[1]=data[5*i+3];
			c[2]=data[5*i+4];
			SetUpBumps(n,c,l,s,t);
			glMultiTexCoord2fARB(GL_TEXTURE0_ARB,data[5*i]     , data[5*i+1]); 
			glMultiTexCoord2fARB(GL_TEXTURE1_ARB,data[5*i]+c[0], data[5*i+1]+c[1]); 
			glVertex3f(data[5*i+2], data[5*i+3], data[5*i+4]);
		}
		// Back Face	
		n[0]=0.0f;		n[1]=0.0f;		n[2]=-1.0f;	
		s[0]=-1.0f;		s[1]=0.0f;		s[2]=0.0f;
		t[0]=0.0f;		t[1]=1.0f;		t[2]=0.0f;
		for (i=4; i<8; i++) {	
			c[0]=data[5*i+2];		
			c[1]=data[5*i+3];
			c[2]=data[5*i+4];
			SetUpBumps(n,c,l,s,t);
			glMultiTexCoord2fARB(GL_TEXTURE0_ARB,data[5*i]     , data[5*i+1]); 
			glMultiTexCoord2fARB(GL_TEXTURE1_ARB,data[5*i]+c[0], data[5*i+1]+c[1]); 
			glVertex3f(data[5*i+2], data[5*i+3], data[5*i+4]);
		}
		// Top Face	
		n[0]=0.0f;		n[1]=1.0f;		n[2]=0.0f;		
		s[0]=1.0f;		s[1]=0.0f;		s[2]=0.0f;
		t[0]=0.0f;		t[1]=0.0f;		t[2]=-1.0f;
		for (i=8; i<12; i++) {	
			c[0]=data[5*i+2];		
			c[1]=data[5*i+3];
			c[2]=data[5*i+4];
			SetUpBumps(n,c,l,s,t);
			glMultiTexCoord2fARB(GL_TEXTURE0_ARB,data[5*i]     , data[5*i+1]     ); 
			glMultiTexCoord2fARB(GL_TEXTURE1_ARB,data[5*i]+c[0], data[5*i+1]+c[1]); 
			glVertex3f(data[5*i+2], data[5*i+3], data[5*i+4]);
		}
		// Bottom Face
		n[0]=0.0f;		n[1]=-1.0f;		n[2]=0.0f;		
		s[0]=-1.0f;		s[1]=0.0f;		s[2]=0.0f;
		t[0]=0.0f;		t[1]=0.0f;		t[2]=-1.0f;
		for (i=12; i<16; i++) {	
			c[0]=data[5*i+2];		
			c[1]=data[5*i+3];
			c[2]=data[5*i+4];
			SetUpBumps(n,c,l,s,t);
			glMultiTexCoord2fARB(GL_TEXTURE0_ARB,data[5*i]     , data[5*i+1]     ); 
			glMultiTexCoord2fARB(GL_TEXTURE1_ARB,data[5*i]+c[0], data[5*i+1]+c[1]); 
			glVertex3f(data[5*i+2], data[5*i+3], data[5*i+4]);
		}
		// Right Face	
		n[0]=1.0f;		n[1]=0.0f;		n[2]=0.0f;		
		s[0]=0.0f;		s[1]=0.0f;		s[2]=-1.0f;
		t[0]=0.0f;		t[1]=1.0f;		t[2]=0.0f;
		for (i=16; i<20; i++) {	
			c[0]=data[5*i+2];		
			c[1]=data[5*i+3];
			c[2]=data[5*i+4];
			SetUpBumps(n,c,l,s,t);
			glMultiTexCoord2fARB(GL_TEXTURE0_ARB,data[5*i]     , data[5*i+1]     ); 
			glMultiTexCoord2fARB(GL_TEXTURE1_ARB,data[5*i]+c[0], data[5*i+1]+c[1]); 
			glVertex3f(data[5*i+2], data[5*i+3], data[5*i+4]);
		}
		// Left Face
		n[0]=-1.0f;		n[1]=0.0f;		n[2]=0.0f;		
		s[0]=0.0f;		s[1]=0.0f;		s[2]=1.0f;
		t[0]=0.0f;		t[1]=1.0f;		t[2]=0.0f;
		for (i=20; i<24; i++) {	
			c[0]=data[5*i+2];		
			c[1]=data[5*i+3];
			c[2]=data[5*i+4];
			SetUpBumps(n,c,l,s,t);
			glMultiTexCoord2fARB(GL_TEXTURE0_ARB,data[5*i]     , data[5*i+1]     ); 
			glMultiTexCoord2fARB(GL_TEXTURE1_ARB,data[5*i]+c[0], data[5*i+1]+c[1]); 
			glVertex3f(data[5*i+2], data[5*i+3], data[5*i+4]);
		}		
	glEnd();
	
/* PASS#2	Use Texture "Base"
			Blend GL_DST_COLOR To GL_SRC_COLOR (Multiplies By 2)
			Lighting Enabled
			No Offset Texture-Coordinates
			*/	
	glActiveTextureARB(GL_TEXTURE1_ARB);		
	glDisable(GL_TEXTURE_2D);
	glActiveTextureARB(GL_TEXTURE0_ARB);			
	if (!emboss) {						
		glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
		glBindTexture(GL_TEXTURE_2D,texture[filter]);
		glBlendFunc(GL_DST_COLOR,GL_SRC_COLOR);
		glEnable(GL_BLEND);
		glEnable(GL_LIGHTING);
		doCube();
	}

	xrot+=xspeed;
	yrot+=yspeed;
	if (xrot>360.0f) xrot-=360.0f;
	if (xrot<0.0f) xrot+=360.0f;
	if (yrot>360.0f) yrot-=360.0f;
	if (yrot<0.0f) yrot+=360.0f;

/* LAST PASS:	Do The Logos! */	
	doLogo();

	return true;										// Keep Going
}
bool doMeshNoBumps(void) {

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	// Clear The Screen And The Depth Buffer
	glLoadIdentity();									// Reset The View
	glTranslatef(0.0f,0.0f,z);

	glRotatef(xrot,1.0f,0.0f,0.0f);
	glRotatef(yrot,0.0f,1.0f,0.0f);	
	if (useMultitexture) {
		glActiveTextureARB(GL_TEXTURE1_ARB);		
		glDisable(GL_TEXTURE_2D);
		glActiveTextureARB(GL_TEXTURE0_ARB);
	}
	glDisable(GL_BLEND);
	glBindTexture(GL_TEXTURE_2D,texture[filter]);	
	glBlendFunc(GL_DST_COLOR,GL_SRC_COLOR);
	glEnable(GL_LIGHTING);
	doCube();
	
	xrot+=xspeed;
	yrot+=yspeed;
	if (xrot>360.0f) xrot-=360.0f;
	if (xrot<0.0f) xrot+=360.0f;
	if (yrot>360.0f) yrot-=360.0f;
	if (yrot<0.0f) yrot+=360.0f;

/* LAST PASS:	Do The Logos! */	
	doLogo();

	return true;										// Keep Going
}

bool DrawGLScene(GLvoid)								// Here's Where We Do All The Drawing
{	if (bumps) {
		if (useMultitexture && maxTexelUnits>1)
			return doMesh2TexelUnits();	
		else return doMesh1TexelUnits();	
	}
	else return doMeshNoBumps();
}

GLvoid KillGLWindow(GLvoid)								// Properly Kill The Window
{
	if (hRC)											// Do We Have A Rendering Context?
	{
		if (!wglMakeCurrent(NULL,NULL))					// Are We Able To Release The DC And RC Contexts?
		{
			MessageBox(NULL,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		}

		if (!wglDeleteContext(hRC))						// Are We Able To Delete The RC?
		{
			MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		}
		hRC=NULL;										// Set RC To NULL
	}

	if (hDC && !ReleaseDC(hWnd,hDC))					// Are We Able To Release The DC
	{
		MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		hDC=NULL;										// Set DC To NULL
	}

	if (hWnd && !DestroyWindow(hWnd))					// Are We Able To Destroy The Window?
	{
		MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		hWnd=NULL;										// Set hWnd To NULL
	}

	if (fullscreen)										// Are We In Fullscreen Mode?
	{
		ChangeDisplaySettings(NULL,0);					// If So Switch Back To The Desktop
		ShowCursor(TRUE);								// Show Mouse Pointer
	}
}

/*	This Code Creates Our OpenGL Window.  Parameters Are:					*
 *	title			- Title To Appear At The Top Of The Window				*
 *	width			- Width Of The GL Window Or Fullscreen Mode				*
 *	height			- Height Of The GL Window Or Fullscreen Mode			*
 *	bits			- Number Of Bits To Use For Color (8/16/24/32)			*
 *	fullscreenflag	- Use Fullscreen Mode (TRUE) Or Windowed Mode (FALSE)	*/
 
BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag)
{
	GLuint		PixelFormat;			// Holds The Results After Searching For A Match
	HINSTANCE	hInstance;				// Holds The Instance Of The Application
	WNDCLASS	wc;						// Windows Class Structure
	DWORD		dwExStyle;				// Window Extended Style
	DWORD		dwStyle;				// Window Style