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在第三章节Smoother示例程序基础上，加多了一个月亮的渲染，它会用29个纹理图经过一定时间切换图片，进行循环播放动画一样。属于第七章内容——高级纹理

// TextureArrays.cpp// OpenGL SuperBible// Demonstrates Passing a TextureArray to a shader// Program by Richard S. Wright Jr.#pragma comment(lib, "gltools.lib")#include 
   
    	// OpenGL toolkit#include 
    
     #include 
     
      #ifdef __APPLE__#include 
      
       #else#define FREEGLUT_STATIC#include 
       
        #endifGLShaderManager shaderManager;GLFrustum viewFrustum;GLBatch smallStarBatch;GLBatch mediumStarBatch;GLBatch largeStarBatch;GLBatch mountainRangeBatch;GLBatch moonBatch;GLuint  starTexture;GLuint	starFieldShader;	// The point sprite shaderGLint	locMVP;				// The location of the ModelViewProjection matrix uniformGLint	locStarTexture;		// The location of the  texture uniformGLuint  moonTexture;GLuint  moonShader;GLint   locMoonMVP;GLint   locMoonTexture;GLint	locMoonTime;GLint   locTimeStamp;       // The location of the time stamp// Array of small stars#define SMALL_STARS     100#define MEDIUM_STARS     40#define LARGE_STARS      15#define SCREEN_X        800#define SCREEN_Y        600// Load a TGA as a 2D Texture. Completely initialize the statebool LoadTGATexture(const char *szFileName, GLenum minFilter, GLenum magFilter, GLenum wrapMode){	GLbyte *pBits;	int nWidth, nHeight, nComponents;	GLenum eFormat;	// Read the texture bits	pBits = gltReadTGABits(szFileName, &nWidth, &nHeight, &nComponents, &eFormat);	if (pBits == NULL)		return false;	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapMode);	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapMode);	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, minFilter);	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, magFilter);	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);	glTexImage2D(GL_TEXTURE_2D, 0, nComponents, nWidth, nHeight, 0,		eFormat, GL_UNSIGNED_BYTE, pBits);	free(pBits);	if (minFilter == GL_LINEAR_MIPMAP_LINEAR ||		minFilter == GL_LINEAR_MIPMAP_NEAREST ||		minFilter == GL_NEAREST_MIPMAP_LINEAR ||		minFilter == GL_NEAREST_MIPMAP_NEAREST)		glGenerateMipmap(GL_TEXTURE_2D);	return true;}///// Called to draw scenevoid RenderScene(void){	static CStopWatch timer;	// Clear the window	glClear(GL_COLOR_BUFFER_BIT);	// Everything is white	GLfloat vWhite[] = { 1.0f, 1.0f, 1.0f, 1.0f };	glBindTexture(GL_TEXTURE_2D, starTexture);	glUseProgram(starFieldShader);	glUniformMatrix4fv(locMVP, 1, GL_FALSE, viewFrustum.GetProjectionMatrix());	glUniform1i(locStarTexture, 0);	// Draw small stars	glPointSize(4.0f);	smallStarBatch.Draw();	// Draw medium sized stars	glPointSize(8.0f);	mediumStarBatch.Draw();	// Draw largest stars	glPointSize(12.0f);	largeStarBatch.Draw();	// Draw distant horizon	shaderManager.UseStockShader(GLT_SHADER_FLAT, viewFrustum.GetProjectionMatrix(), vWhite);	glLineWidth(3.5);	mountainRangeBatch.Draw();	// Draw the "moon"	glBindTexture(GL_TEXTURE_2D_ARRAY, moonTexture);	glUseProgram(moonShader);	glUniformMatrix4fv(locMoonMVP, 1, GL_FALSE, viewFrustum.GetProjectionMatrix());	glUniform1i(locMoonTexture, 0);	// fTime goes from 0.0 to 28.0 and recycles	float fTime = timer.GetElapsedSeconds();	fTime = fmod(fTime, 28.0f);	glUniform1f(locTimeStamp, fTime);	moonBatch.Draw();	// Swap buffers	glutSwapBuffers();	glutPostRedisplay();}// This function does any needed initialization on the rendering// context. void SetupRC(){	M3DVector3f vVerts[SMALL_STARS];       // SMALL_STARS is the largest batch we are going to need	int i;	glEnable(GL_POINT_SPRITE);	shaderManager.InitializeStockShaders();	// A number of shipping drivers are not conformant to the current OpenGL	// spec and require this. NVidia... in particular. The OpenGL specification	// states that this is always "on", in fact you can't enable or disable it	// anymore. Adding this lines "fixes" this on non-conformant drivers, but	// be aware, if you have a pure core (and working correctly) GL context, 	//you should not do this	glEnable(GL_POINT_SPRITE);	// Populate star list	smallStarBatch.Begin(GL_POINTS, SMALL_STARS);	for (i = 0; i < SMALL_STARS; i++)	{		vVerts[i][0] = (GLfloat)(rand() % SCREEN_X);		vVerts[i][1] = (GLfloat)(rand() % (SCREEN_Y - 100)) + 100.0f;		vVerts[i][2] = 0.0f;	}	smallStarBatch.CopyVertexData3f(vVerts);	smallStarBatch.End();	// Populate star list	mediumStarBatch.Begin(GL_POINTS, MEDIUM_STARS);	for (i = 0; i < MEDIUM_STARS; i++)	{		vVerts[i][0] = (GLfloat)(rand() % SCREEN_X);		vVerts[i][1] = (GLfloat)(rand() % (SCREEN_Y - 100)) + 100.0f;		vVerts[i][2] = 0.0f;	}	mediumStarBatch.CopyVertexData3f(vVerts);	mediumStarBatch.End();	// Populate star list	largeStarBatch.Begin(GL_POINTS, LARGE_STARS);	for (i = 0; i < LARGE_STARS; i++)	{		vVerts[i][0] = (GLfloat)(rand() % SCREEN_X);		vVerts[i][1] = (GLfloat)(rand() % (SCREEN_Y - 100)) + 100.0f;		vVerts[i][2] = 0.0f;	}	largeStarBatch.CopyVertexData3f(vVerts);	largeStarBatch.End();	M3DVector3f vMountains[12] = { 0.0f, 25.0f, 0.0f,								 50.0f, 100.0f, 0.0f,								 100.0f, 25.0f, 0.0f,								225.0f, 125.0f, 0.0f,								300.0f, 50.0f, 0.0f,								375.0f, 100.0f, 0.0f,								460.0f, 25.0f, 0.0f,								525.0f, 100.0f, 0.0f,								600.0f, 20.0f, 0.0f,								675.0f, 70.0f, 0.0f,								750.0f, 25.0f, 0.0f,								800.0f, 90.0f, 0.0f };	mountainRangeBatch.Begin(GL_LINE_STRIP, 12);	mountainRangeBatch.CopyVertexData3f(vMountains);	mountainRangeBatch.End();	// The Moon	GLfloat x = 700.0f;     // Location and radius of moon	GLfloat y = 500.0f;	GLfloat r = 50.0f;	GLfloat angle = 0.0f;   // Another looping variable	moonBatch.Begin(GL_TRIANGLE_FAN, 4, 1);	moonBatch.MultiTexCoord2f(0, 0.0f, 0.0f);	moonBatch.Vertex3f(x - r, y - r, 0.0f);	moonBatch.MultiTexCoord2f(0, 1.0f, 0.0f);	moonBatch.Vertex3f(x + r, y - r, 0.0f);	moonBatch.MultiTexCoord2f(0, 1.0f, 1.0f);	moonBatch.Vertex3f(x + r, y + r, 0.0f);	moonBatch.MultiTexCoord2f(0, 0.0f, 1.0f);	moonBatch.Vertex3f(x - r, y + r, 0.0f);	moonBatch.End();	// Black background	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);	// Turn on line antialiasing, and give hint to do the best	// job possible.	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);	glEnable(GL_BLEND);	glEnable(GL_LINE_SMOOTH);	glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);	starFieldShader = gltLoadShaderPairWithAttributes("StarField.vp", "StarField.fp", 1, GLT_ATTRIBUTE_VERTEX, "vVertex");	locMVP = glGetUniformLocation(starFieldShader, "mvpMatrix");	locStarTexture = glGetUniformLocation(starFieldShader, "starImage");	moonShader = gltLoadShaderPairWithAttributes("MoonShader.vp", "MoonShader.fp", 2, GLT_ATTRIBUTE_VERTEX, "vVertex",		GLT_ATTRIBUTE_TEXTURE0, "vTexCoords");	locMoonMVP = glGetUniformLocation(moonShader, "mvpMatrix");	locMoonTexture = glGetUniformLocation(moonShader, "moonImage");	locMoonTime = glGetUniformLocation(moonShader, "fTime");	glGenTextures(1, &starTexture);	glBindTexture(GL_TEXTURE_2D, starTexture);	LoadTGATexture("Star.tga", GL_LINEAR_MIPMAP_LINEAR, GL_LINEAR, GL_CLAMP_TO_EDGE);	glGenTextures(1, &moonTexture);	glBindTexture(GL_TEXTURE_2D_ARRAY, moonTexture);	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);	glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);	glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);	glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_LINEAR);	glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_LINEAR);	glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, GL_RGBA, 64, 64, 30, 0,		GL_BGRA, GL_UNSIGNED_BYTE, NULL);	for (int i = 0; i < 29; i++) {		char cFile[32];		sprintf_s(cFile, "moon%02d.tga", i); //'sprintf' unsafe, replace with 'sprintf_s'		GLbyte *pBits;		int nWidth, nHeight, nComponents;		GLenum eFormat;		// Read the texture bits		pBits = gltReadTGABits(cFile, &nWidth, &nHeight, &nComponents, &eFormat);		glTexSubImage3D(GL_TEXTURE_2D_ARRAY, 0, 0, 0, i, nWidth, nHeight, 1, GL_BGRA, GL_UNSIGNED_BYTE, pBits);				free(pBits);	}}void ChangeSize(int w, int h){	// Prevent a divide by zero	if (h == 0)		h = 1;	// Set Viewport to window dimensions	glViewport(0, 0, w, h);	// Establish clipping volume (left, right, bottom, top, near, far)	viewFrustum.SetOrthographic(0.0f, SCREEN_X, 0.0f, SCREEN_Y, -1.0f, 1.0f);}int main(int argc, char* argv[]){	glutInit(&argc, argv);	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);	glutInitWindowSize(800, 600);	glutCreateWindow("Texture Arrays");	glutReshapeFunc(ChangeSize);	glutDisplayFunc(RenderScene);	GLenum err = glewInit();	if (GLEW_OK != err) {		fprintf(stderr, "GLEW Error: %s\n", glewGetErrorString(err));		return 1;	}	SetupRC();	glutMainLoop();	return 0;}
       
      
     
    
   

// MoonShader// Vertex Shader// Richard S. Wright Jr.// OpenGL SuperBible#version 130in vec4 vVertex;in vec4 vTexCoords;uniform mat4 mvpMatrix;uniform float fTime;smooth out vec3 vMoonCoords;void main(void)     {     vMoonCoords.st = vTexCoords.st;    vMoonCoords.p = fTime;    gl_Position = mvpMatrix * vVertex;    }

// MoonShader// Fragment Shader// Richard S. Wright Jr.// OpenGL SuperBible#version 130// Another NVidia Driver non-conformance bug// You should not have to put this here for a 3.3 driver.#extension GL_EXT_gpu_shader4: enableout vec4 vFragColor;uniform sampler2DArray moonImage;smooth in vec3 vMoonCoords;void main(void)   {    vFragColor = texture2DArray(moonImage, vMoonCoords.stp);   }

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