示例#1
0
// Draw a cylinder. Much like gluCylinder
void gltMakeCylinder(GLTriangleBatch& cylinderBatch, GLfloat baseRadius, GLfloat topRadius, 
			GLfloat fLength, GLint numSlices, GLint numStacks)
	{	
    float fRadiusStep = (topRadius - baseRadius) / float(numStacks);

	GLfloat fStepSizeSlice = (3.1415926536f * 2.0f) / float(numSlices);

	M3DVector3f vVertex[4];
	M3DVector3f vNormal[4];
	M3DVector2f vTexture[4];

    cylinderBatch.BeginMesh(numSlices * numStacks * 6);

    GLfloat ds = 1.0f / float(numSlices);
	GLfloat dt = 1.0f / float(numStacks);
	GLfloat s;
	GLfloat t;

	for (int i = 0; i < numStacks; i++) 
		{
		if(i == 0)			
			t = 0.0f;
		else
			t = float(i) * dt;

		float tNext;
		if(i == (numStacks - 1))
			tNext = 1.0f;
		else
			tNext = float(i+1) * dt;
	
		float fCurrentRadius = baseRadius + (fRadiusStep * float(i));
		float fNextRadius = baseRadius + (fRadiusStep * float(i+1));
		float theyta;
		float theytaNext;

		float fCurrentZ = float(i) * (fLength / float(numStacks)); 
		float fNextZ = float(i+1) * (fLength / float(numStacks));
		
		float zNormal = 0.0f;
		if(!m3dCloseEnough(baseRadius - topRadius, 0.0f, 0.00001f))
			{
			// Rise over run...
			zNormal = (baseRadius - topRadius);
			}
		
		for (int j = 0; j < numSlices; j++) 
			{		
			if(j == 0)
				s = 0.0f;
			else
				s = float(j) * ds;

			float sNext;
			if(j == (numSlices -1))
				sNext = 1.0f;
			else
				sNext = float(j+1) * ds;

			theyta = fStepSizeSlice * float(j);
			if(j == (numSlices - 1))
				theytaNext = 0.0f;
			else
				theytaNext = fStepSizeSlice * (float(j+1));
				
			// Inner First
			vVertex[1][0] = cos(theyta) * fCurrentRadius;	// X	
			vVertex[1][1] = sin(theyta) * fCurrentRadius;	// Y
			vVertex[1][2] = fCurrentZ;						// Z
			
			vNormal[1][0] = vVertex[1][0];					// Surface Normal, same for everybody
			vNormal[1][1] = vVertex[1][1];
			vNormal[1][2] = zNormal;
			m3dNormalizeVector3(vNormal[1]);
			
			vTexture[1][0] = s;					// Texture Coordinates, I have no idea...
			vTexture[1][1] = t;
	
			// Outer First
			vVertex[0][0] = cos(theyta) * fNextRadius;	// X	
			vVertex[0][1] = sin(theyta) * fNextRadius;	// Y
			vVertex[0][2] = fNextZ;						// Z
			
			if(!m3dCloseEnough(fNextRadius, 0.0f, 0.00001f)) {
				vNormal[0][0] = vVertex[0][0];					// Surface Normal, same for everybody
				vNormal[0][1] = vVertex[0][1];					// For cones, tip is tricky
				vNormal[0][2] = zNormal;
				m3dNormalizeVector3(vNormal[0]);
				}
			else
				memcpy(vNormal[0], vNormal[1], sizeof(M3DVector3f));
		
			
			vTexture[0][0] = s;					// Texture Coordinates, I have no idea...
			vTexture[0][1] = tNext;
			
			// Inner second
			vVertex[3][0] = cos(theytaNext) * fCurrentRadius;	// X	
			vVertex[3][1] = sin(theytaNext) * fCurrentRadius;	// Y
			vVertex[3][2] = fCurrentZ;						// Z
			
			vNormal[3][0] = vVertex[3][0];					// Surface Normal, same for everybody
			vNormal[3][1] = vVertex[3][1];
			vNormal[3][2] = zNormal;
			m3dNormalizeVector3(vNormal[3]);

			vTexture[3][0] = sNext;					// Texture Coordinates, I have no idea...
			vTexture[3][1] = t;

			// Outer second
			vVertex[2][0] = cos(theytaNext) * fNextRadius;	// X	
			vVertex[2][1] = sin(theytaNext) * fNextRadius;	// Y
			vVertex[2][2] = fNextZ;						// Z
			
			if(!m3dCloseEnough(fNextRadius, 0.0f, 0.00001f)) {
				vNormal[2][0] = vVertex[2][0];					// Surface Normal, same for everybody
				vNormal[2][1] = vVertex[2][1];
				vNormal[2][2] = zNormal;
				m3dNormalizeVector3(vNormal[2]);
				}
			else
				memcpy(vNormal[2], vNormal[3], sizeof(M3DVector3f));
				

			vTexture[2][0] = sNext;					// Texture Coordinates, I have no idea...
			vTexture[2][1] = tNext;
		
			cylinderBatch.AddTriangle(vVertex, vNormal, vTexture);			
			
			// Rearrange for next triangle
			memcpy(vVertex[0], vVertex[1], sizeof(M3DVector3f));
			memcpy(vNormal[0], vNormal[1], sizeof(M3DVector3f));
			memcpy(vTexture[0], vTexture[1], sizeof(M3DVector2f));
			
			memcpy(vVertex[1], vVertex[3], sizeof(M3DVector3f));
			memcpy(vNormal[1], vNormal[3], sizeof(M3DVector3f));
			memcpy(vTexture[1], vTexture[3], sizeof(M3DVector2f));
					
			cylinderBatch.AddTriangle(vVertex, vNormal, vTexture);			
			}
        }
	cylinderBatch.End();
	}
示例#2
0
/////////////////////////////////////////////////////////////////////////////////////////////////
// Make a sphere
void gltMakeSphere(GLTriangleBatch& sphereBatch, GLfloat fRadius, GLint iSlices, GLint iStacks)
	{
    GLfloat drho = (GLfloat)(3.141592653589) / (GLfloat) iStacks;
    GLfloat dtheta = 2.0f * (GLfloat)(3.141592653589) / (GLfloat) iSlices;
	GLfloat ds = 1.0f / (GLfloat) iSlices;
	GLfloat dt = 1.0f / (GLfloat) iStacks;
	GLfloat t = 1.0f;	
	GLfloat s = 0.0f;
    GLint i, j;     // Looping variables
    
    sphereBatch.BeginMesh(iSlices * iStacks * 6);
	for (i = 0; i < iStacks; i++) 
		{
		GLfloat rho = (GLfloat)i * drho;
		GLfloat srho = (GLfloat)(sin(rho));
		GLfloat crho = (GLfloat)(cos(rho));
		GLfloat srhodrho = (GLfloat)(sin(rho + drho));
		GLfloat crhodrho = (GLfloat)(cos(rho + drho));
		
        // Many sources of OpenGL sphere drawing code uses a triangle fan
        // for the caps of the sphere. This however introduces texturing 
        // artifacts at the poles on some OpenGL implementations
        s = 0.0f;
		M3DVector3f vVertex[4];
		M3DVector3f vNormal[4];
		M3DVector2f vTexture[4];

		for ( j = 0; j < iSlices; j++) 
			{
			GLfloat theta = (j == iSlices) ? 0.0f : j * dtheta;
			GLfloat stheta = (GLfloat)(-sin(theta));
			GLfloat ctheta = (GLfloat)(cos(theta));
			
			GLfloat x = stheta * srho;
			GLfloat y = ctheta * srho;
			GLfloat z = crho;
        
			vTexture[0][0] = s;
			vTexture[0][1] = t;
			vNormal[0][0] = x;
			vNormal[0][1] = y;
			vNormal[0][2] = z;
			vVertex[0][0] = x * fRadius;
			vVertex[0][1] = y * fRadius;
			vVertex[0][2] = z * fRadius;
			
            x = stheta * srhodrho;
			y = ctheta * srhodrho;
			z = crhodrho;

 			vTexture[1][0] = s;
			vTexture[1][1] = t - dt;
			vNormal[1][0] = x;
			vNormal[1][1] = y;
			vNormal[1][2] = z;
			vVertex[1][0] = x * fRadius;
			vVertex[1][1] = y * fRadius;
			vVertex[1][2] = z * fRadius;
			

			theta = ((j+1) == iSlices) ? 0.0f : (j+1) * dtheta;
			stheta = (GLfloat)(-sin(theta));
			ctheta = (GLfloat)(cos(theta));
			
			x = stheta * srho;
			y = ctheta * srho;
			z = crho;
        
            s += ds;
			vTexture[2][0] = s;
			vTexture[2][1] = t;
			vNormal[2][0] = x;
			vNormal[2][1] = y;
			vNormal[2][2] = z;
			vVertex[2][0] = x * fRadius;
			vVertex[2][1] = y * fRadius;
			vVertex[2][2] = z * fRadius;
			
            x = stheta * srhodrho;
			y = ctheta * srhodrho;
			z = crhodrho;

 			vTexture[3][0] = s;
			vTexture[3][1] = t - dt;
			vNormal[3][0] = x;
			vNormal[3][1] = y;
			vNormal[3][2] = z;
			vVertex[3][0] = x * fRadius;
			vVertex[3][1] = y * fRadius;
			vVertex[3][2] = z * fRadius;
		
			sphereBatch.AddTriangle(vVertex, vNormal, vTexture);			
			
			// Rearrange for next triangle
			memcpy(vVertex[0], vVertex[1], sizeof(M3DVector3f));
			memcpy(vNormal[0], vNormal[1], sizeof(M3DVector3f));
			memcpy(vTexture[0], vTexture[1], sizeof(M3DVector2f));
			
			memcpy(vVertex[1], vVertex[3], sizeof(M3DVector3f));
			memcpy(vNormal[1], vNormal[3], sizeof(M3DVector3f));
			memcpy(vTexture[1], vTexture[3], sizeof(M3DVector2f));
					
			sphereBatch.AddTriangle(vVertex, vNormal, vTexture);			
			}
        t -= dt;
        }
		sphereBatch.End();
    }
示例#3
0
void gltMakeDisk(GLTriangleBatch& diskBatch, GLfloat innerRadius, GLfloat outerRadius, GLint nSlices, GLint nStacks)
	{
	// How much to step out each stack
	GLfloat fStepSizeRadial = outerRadius - innerRadius;
	if(fStepSizeRadial < 0.0f)			// Dum dum...
		fStepSizeRadial *= -1.0f;

	fStepSizeRadial /= float(nStacks);
	
	GLfloat fStepSizeSlice = (3.1415926536f * 2.0f) / float(nSlices);
	
	diskBatch.BeginMesh(nSlices * nStacks * 6);
	
	M3DVector3f vVertex[4];
	M3DVector3f vNormal[4];
	M3DVector2f vTexture[4];
	
	float fRadialScale = 1.0f / outerRadius;
	
	for(GLint i = 0; i < nStacks; i++)			// Stacks
		{
		float theyta;
		float theytaNext;
		for(GLint j = 0; j < nSlices; j++)     // Slices
			{
			float inner = innerRadius + (float(i)) * fStepSizeRadial;
			float outer = innerRadius + (float(i+1)) * fStepSizeRadial;
			
			theyta = fStepSizeSlice * float(j);
			if(j == (nSlices - 1))
				theytaNext = 0.0f;
			else
				theytaNext = fStepSizeSlice * (float(j+1));
				
			// Inner First
			vVertex[0][0] = cos(theyta) * inner;	// X	
			vVertex[0][1] = sin(theyta) * inner;	// Y
			vVertex[0][2] = 0.0f;					// Z
			
			vNormal[0][0] = 0.0f;					// Surface Normal, same for everybody
			vNormal[0][1] = 0.0f;
			vNormal[0][2] = 1.0f;
			
			vTexture[0][0] = ((vVertex[0][0] * fRadialScale) + 1.0f) * 0.5f;	
			vTexture[0][1] = ((vVertex[0][1] * fRadialScale) + 1.0f) * 0.5f;
			
			// Outer First
			vVertex[1][0] = cos(theyta) * outer;	// X	
			vVertex[1][1] = sin(theyta) * outer;	// Y
			vVertex[1][2] = 0.0f;					// Z
			
			vNormal[1][0] = 0.0f;					// Surface Normal, same for everybody
			vNormal[1][1] = 0.0f;
			vNormal[1][2] = 1.0f;
			
			vTexture[1][0] = ((vVertex[1][0] * fRadialScale) + 1.0f) * 0.5f;
			vTexture[1][1] = ((vVertex[1][1] * fRadialScale) + 1.0f) * 0.5f;
			
			// Inner Second
			vVertex[2][0] = cos(theytaNext) * inner;	// X	
			vVertex[2][1] = sin(theytaNext) * inner;	// Y
			vVertex[2][2] = 0.0f;					// Z
			
			vNormal[2][0] = 0.0f;					// Surface Normal, same for everybody
			vNormal[2][1] = 0.0f;
			vNormal[2][2] = 1.0f;
			
			vTexture[2][0] = ((vVertex[2][0] * fRadialScale) + 1.0f) * 0.5f;
			vTexture[2][1] = ((vVertex[2][1] * fRadialScale) + 1.0f) * 0.5f;
			
			
			// Outer Second
			vVertex[3][0] = cos(theytaNext) * outer;	// X	
			vVertex[3][1] = sin(theytaNext) * outer;	// Y
			vVertex[3][2] = 0.0f;					// Z
			
			vNormal[3][0] = 0.0f;					// Surface Normal, same for everybody
			vNormal[3][1] = 0.0f;
			vNormal[3][2] = 1.0f;
			
			vTexture[3][0] = ((vVertex[3][0] * fRadialScale) + 1.0f) * 0.5f;
			vTexture[3][1] = ((vVertex[3][1] * fRadialScale) + 1.0f) * 0.5f;
			
			diskBatch.AddTriangle(vVertex, vNormal, vTexture);			
			
			// Rearrange for next triangle
			memcpy(vVertex[0], vVertex[1], sizeof(M3DVector3f));
			memcpy(vNormal[0], vNormal[1], sizeof(M3DVector3f));
			memcpy(vTexture[0], vTexture[1], sizeof(M3DVector2f));
			
			memcpy(vVertex[1], vVertex[3], sizeof(M3DVector3f));
			memcpy(vNormal[1], vNormal[3], sizeof(M3DVector3f));
			memcpy(vTexture[1], vTexture[3], sizeof(M3DVector2f));
					
			diskBatch.AddTriangle(vVertex, vNormal, vTexture);			
			}
		}
	
	diskBatch.End();
	}
示例#4
0
// Draw a torus (doughnut)  at z = fZVal... torus is in xy plane
void gltMakeTorus(GLTriangleBatch& torusBatch, GLfloat majorRadius, GLfloat minorRadius, GLint numMajor, GLint numMinor)
	{
    double majorStep = 2.0f*M3D_PI / numMajor;
    double minorStep = 2.0f*M3D_PI / numMinor;
    int i, j;
	
    torusBatch.BeginMesh(numMajor * (numMinor+1) * 6);
    for (i=0; i<numMajor; ++i) 
		{
		double a0 = i * majorStep;
		double a1 = a0 + majorStep;
		GLfloat x0 = (GLfloat) cos(a0);
		GLfloat y0 = (GLfloat) sin(a0);
		GLfloat x1 = (GLfloat) cos(a1);
		GLfloat y1 = (GLfloat) sin(a1);

		M3DVector3f vVertex[4];
		M3DVector3f vNormal[4];
		M3DVector2f vTexture[4];
		
		for (j=0; j<=numMinor; ++j) 
			{
			double b = j * minorStep;
			GLfloat c = (GLfloat) cos(b);
			GLfloat r = minorRadius * c + majorRadius;
			GLfloat z = minorRadius * (GLfloat) sin(b);
			
			// First point
			vTexture[0][0] = (float)(i)/(float)(numMajor);
			vTexture[0][1] = (float)(j)/(float)(numMinor);
			vNormal[0][0] = x0*c;
			vNormal[0][1] = y0*c;
			vNormal[0][2] = z/minorRadius;
			m3dNormalizeVector3(vNormal[0]);
			vVertex[0][0] = x0 * r;
			vVertex[0][1] = y0 * r;
			vVertex[0][2] = z;
			
			// Second point
			vTexture[1][0] = (float)(i+1)/(float)(numMajor);
			vTexture[1][1] = (float)(j)/(float)(numMinor);
			vNormal[1][0] = x1*c;
			vNormal[1][1] = y1*c;
			vNormal[1][2] = z/minorRadius;
			m3dNormalizeVector3(vNormal[1]);
			vVertex[1][0] = x1*r;
			vVertex[1][1] = y1*r;
			vVertex[1][2] = z;

			// Next one over
			b = (j+1) * minorStep;
			c = (GLfloat) cos(b);
			r = minorRadius * c + majorRadius;
			z = minorRadius * (GLfloat) sin(b);
						
			// Third (based on first)
			vTexture[2][0] = (float)(i)/(float)(numMajor);
			vTexture[2][1] = (float)(j+1)/(float)(numMinor);
			vNormal[2][0] = x0*c;
			vNormal[2][1] = y0*c;
			vNormal[2][2] = z/minorRadius;
			m3dNormalizeVector3(vNormal[2]);
			vVertex[2][0] = x0 * r;
			vVertex[2][1] = y0 * r;
			vVertex[2][2] = z;
			
			// Fourth (based on second)
			vTexture[3][0] = (float)(i+1)/(float)(numMajor);
			vTexture[3][1] = (float)(j+1)/(float)(numMinor);
			vNormal[3][0] = x1*c;
			vNormal[3][1] = y1*c;
			vNormal[3][2] = z/minorRadius;
			m3dNormalizeVector3(vNormal[3]);
			vVertex[3][0] = x1*r;
			vVertex[3][1] = y1*r;
			vVertex[3][2] = z;

			torusBatch.AddTriangle(vVertex, vNormal, vTexture);			
			
			// Rearrange for next triangle
			memcpy(vVertex[0], vVertex[1], sizeof(M3DVector3f));
			memcpy(vNormal[0], vNormal[1], sizeof(M3DVector3f));
			memcpy(vTexture[0], vTexture[1], sizeof(M3DVector2f));
			
			memcpy(vVertex[1], vVertex[3], sizeof(M3DVector3f));
			memcpy(vNormal[1], vNormal[3], sizeof(M3DVector3f));
			memcpy(vTexture[1], vTexture[3], sizeof(M3DVector2f));
					
			torusBatch.AddTriangle(vVertex, vNormal, vTexture);			
			}
		}
	torusBatch.End();
	}