C++ perspective函数代码示例

glm::mat4 Frustum::GetPerspectiveProjection() const
{
	glm::mat4 perspective(0);

	float aspect = height / width;
	float fovScale = 1.0f / std::tan(fovY * 0.5f);
	perspective[0][0] = fovScale * aspect;
	perspective[1][1] = fovScale;
	perspective[2][2] = (near_z + far_z) / (near_z - far_z);
	perspective[3][2] = 2 * near_z * far_z / (near_z - far_z);
	perspective[2][3] = -1.0f;

	return perspective;
}

void Renderer::updateProjMatrix(float width, float height)
{
	this->wheight=height;
	this->wwidth=width;
	float nearClip = 0.5f;
	float farClip  = 1000.0f;
	float fov_deg = 45.0f;
	float aspect = (float)width/(float)height;
	this->projMatrix=perspective(fov_deg, aspect,nearClip,farClip);
	
	this->modelShader.use();
	this->modelShader.setUniform("projectionMatrix",this->projMatrix);
	glUseProgram(0);
}

//------------------------------------------------------------------------------
void reshape(int w, int h)
{
    g_winSz[0] = w; 
    g_winSz[1] = h;

    perspective(g_transfBlock1.m4_Proj, 45.0f, (float)g_winSz[0] / (float)g_winSz[1], 0.01f, 10.0f);
    //
    // Let's validate again the base of resource management to make sure things keep consistent
    //
    int W = g_winSz[0];
    int H = g_winSz[1];

    glViewport(0, 0, W, H);

    perspective(g_transfBlock1.m4_Proj, 45.0f, (float)g_winSz[0] / (float)g_winSz[1], 0.01f, 10.0f);

    bool failed = nvFX::getResourceRepositorySingleton()->validate(0,0,W,H,1,0,NULL ) ? false : true;
    if(failed)
        assert(!"Oops");
    failed = nvFX::getFrameBufferObjectsRepositorySingleton()->validate(0,0,W,H,1,0,NULL ) ? false : true;
    if(failed)
        assert(!"Oops");
}

void CubMapStudyR::renderReflect()
{
	glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	this->camera->setDeltaTime(glfwGetTime());
	this->camera->DoMovement();

	mat4 model(1.0f);
	mat4 view(1.0f);
	mat4 projection(1.0f);
	view = this->camera->GetLookAt();
	projection = perspective(radians(Camera::aspect), 800.0f / 600.0f, 0.1f, 1000.0f);

	//绘制物体
	model = translate(model, vec3(0.0f, 0.0f, 0.7f));
	model = scale(model, vec3(0.3f, 0.3f, 0.3f));
	
	cubeShader->UseProgram();
	glActiveTexture(GL_TEXTURE0);
	//glBindTexture(GL_TEXTURE_2D, this->cubeTexutrueID);
	glBindTexture(GL_TEXTURE_CUBE_MAP, this->skyBoxTextureID);
	glUniformMatrix4fv(glGetUniformLocation(cubeShader->getProgram(), "view"), 1, GL_FALSE, value_ptr(view));
	glUniformMatrix4fv(glGetUniformLocation(cubeShader->getProgram(), "projection"), 1, GL_FALSE, value_ptr(projection));
	glUniformMatrix4fv(glGetUniformLocation(cubeShader->getProgram(), "model"), 1, GL_FALSE, value_ptr(model));
	glUniform3fv(glGetUniformLocation(cubeShader->getProgram(), "cameraPos"),1, value_ptr(Camera::cameraPos));
	glUniform1i(glGetUniformLocation(cubeShader->getProgram(), "skybox"), 0);
	//glUniform1i(glGetUniformLocation(cubeShader->getProgram(), "Texture1"), 0);

	glBindVertexArray(this->cubeVAO);
	glDrawArrays(GL_TRIANGLES, 0, 36);
	glBindVertexArray(0);
	glBindTexture(GL_TEXTURE_2D, 0);

	//绘制天空盒子
	glDepthFunc(GL_LEQUAL);
	skyboxShader->UseProgram();
	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_CUBE_MAP, this->skyBoxTextureID);
	glUniformMatrix4fv(glGetUniformLocation(skyboxShader->getProgram(), "view"), 1, GL_FALSE, value_ptr(mat4(mat3(view))));
	glUniformMatrix4fv(glGetUniformLocation(skyboxShader->getProgram(), "projection"), 1, GL_FALSE, value_ptr(projection));
	glUniform1i(glGetUniformLocation(skyboxShader->getProgram(), "cubemap"), 0);

	glBindVertexArray(this->skyBoxVAO);
	glDrawArrays(GL_TRIANGLES, 0, 36);
	glBindVertexArray(0);
	glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
	glDepthFunc(GL_LESS);
}

void update() {
  SDL_Event event;
  while (SDL_PollEvent(&event)) {
    if (event.type == SDL_KEYDOWN && event.key.keysym.sym == SDLK_ESCAPE) {
      exit(0);
    }
  }
  glFlush();
  SDL_GL_SwapBuffers();

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glLoadIdentity();

  perspective();
}

void SceneManagerTriangle::Update()
{
	float aspect = (float)m_width / (float)m_height;
	mat4 proj_matrix = perspective(60.0f, aspect, 0.1f, 1000.0f);
	mat4 view_matrix = lookat(vec3(0.0f, 0.0f, 3.0f),
		vec3(0.0f, 0.0f, 0.0f),
		vec3(0.0f, 1.0f, 0.0f));
	float factor = 0;// GetTickCount() / 50 % 360;
	mat4 mv_matrix = view_matrix * translate(m_x_offset, m_y_offset, m_z_offset) * scale(1.0f) * rotate(factor, vec3(0.0f, 1.0f, 0.0f));

	SetUniform(0, mv_matrix);
	SetUniform(1, proj_matrix);

	Soft3dPipeline::Instance()->Clear(0xffffff);
}

	void Renderinstance::createRenderer(const UsedRenderer usedrenderer,const int windowwidth,const int windowheight)
	{
		mutexScopedLock();

		switch (usedrenderer) {
			case UsedRenderer_Opengl:
				m_pRenderer=new opengldrv::OGLRenderer(windowwidth,windowheight);
			default:break;
		}
		
		if (m_pScene) m_pScene->renderer(*m_pRenderer);
		
		m_pRenderer->resize(0,0,windowwidth,windowheight);
		perspective(windowwidth,windowheight);
	}

/* function to reset our viewport after a window resize */
int resizeWindow( int width, int height )
{
    /* Protect against a divide by zero */
    if ( height == 0 )
        height = 1;

    current_height = height;
    current_width = width;

    /* Setup our viewport. */
    glViewport( 0, 0, ( GLsizei )width, ( GLsizei )height );

    perspective();

    return TRUE;
}

void Terrain::updateProjMatrix(float width, float height)
{
	float nearClip = 0.5f;
	float farClip  = 1000.0f;
	float fov_deg = 45.0f;
	float aspect = (float)width/(float)height;
	this->projMatrix=perspective(fov_deg, aspect,nearClip,farClip);

	this->TerrainShader.use();
	this->TerrainShader.setUniform("projectionMatrix",this->projMatrix);
	
	this->surfaceTexShader.use();
	this->surfaceTexShader.setUniform("projectionMatrix",this->projMatrix);
	
	glUseProgram(0);
}

void update()
{
	lastTicks=currentTicks;
	currentTicks=SDL_GetTicks();
	elapsedTime = (currentTicks - lastTicks) / 1000.0f;
	totalTime+=elapsedTime;

	projMatrix = perspective(45.0f, 640.0f / 480.0f, 0.1f, 100.0f);

	viewMatrix = lookAt(cameraPosition, vec3(0.0f, 0.0f, 0.0f), vec3(0.0f, 1.0f, 0.0f));

	for (auto iter = gameObjects.begin(); iter != gameObjects.end(); iter++)
	{
		(*iter)->update();
	}
}

int Mat4::lua_Perspective( lua_State* lua )
{
    int result = 0;
    
    int nargs = lua_gettop( lua );
    if( nargs >= 4 )
    {
        float fov = static_cast<float>( lua_tonumber( lua, 1 ) );
        float aspect = static_cast<float>( lua_tonumber( lua, 2 ) );
        float nearplane = static_cast<float>( lua_tonumber( lua, 3 ) );
        float farplane = static_cast<float>( lua_tonumber( lua, 4 ) );
        result = lua_Write( lua, perspective( fov, aspect, nearplane, farplane ) );
    }
    
    return result;
}

void GraphicsManager::setPerspective(float viewAngle, float clipNear, float clipFar) {
	// Force calling it from the main thread
	if (!Common::isMainThread()) {
		Events::MainThreadFunctor<void> functor(boost::bind(&GraphicsManager::setPerspective, this, viewAngle, clipNear, clipFar));

		return RequestMan.callInMainThread(functor);
	}

	perspective(viewAngle, ((float) _width) / ((float) _height), clipNear, clipFar);

	_projectType = kProjectTypePerspective;

	_viewAngle = viewAngle;
	_clipNear  = clipNear;
	_clipFar   = clipFar;
}

void RaycastCamera::init(u32 screenWidth, u32 screenHeight, f32 fov, f32 nearZ, f32 farZ)
{
    mScreenWidth = (f32)screenWidth;
    mScreenHeight = (f32)screenHeight;
    mFov = fov;
    mNearZ = nearZ;
    mFarZ = farZ;

    mAspectRatio = mScreenWidth / mScreenHeight;

    mProjection = perspective(radians(60.0f),
                              mAspectRatio,
                              mNearZ,
                              mFarZ);
    mProjectionInv = ~mProjection;

    move(vec3(0.0f, 0.0f, 10.0f), quat(0, vec3(0.0f, 0.0f, -1.0f)));

    vec3 rayBottomLeft  = normalize(vec3(mProjectionInv * vec4(-1.0f, -1.0f, 0.0f, 1.0f)));
    vec3 rayBottomRight = vec3(-rayBottomLeft.x,  rayBottomLeft.y, rayBottomLeft.z);
    vec3 rayTopLeft     = vec3( rayBottomLeft.x, -rayBottomLeft.y, rayBottomLeft.z);
    vec3 rayTopRight    = vec3(-rayBottomLeft.x, -rayBottomLeft.y, rayBottomLeft.z);

    f32 cosAngle = dot(rayBottomLeft, normalize(vec3(0.0f, 0.0f, mNearZ)));

    f32 nearLen = -mNearZ / cosAngle;
    f32 farLen = -mFarZ / cosAngle;

    // calculate each corner
    vec3 corBLN = rayBottomLeft * nearLen;
    vec3 corBLF = rayBottomLeft * farLen;

    mCornersInit[kCOR_BottomLeft].nearPos  = corBLN;
    mCornersInit[kCOR_BottomLeft].farPos   = corBLF;

    mCornersInit[kCOR_BottomRight].nearPos = vec3(-corBLN.x, corBLN.y, corBLN.z);
    mCornersInit[kCOR_BottomRight].farPos  = vec3(-corBLF.x, corBLF.y, corBLF.z);

    mCornersInit[kCOR_TopLeft].nearPos = vec3(corBLN.x, -corBLN.y, corBLN.z);
    mCornersInit[kCOR_TopLeft].farPos  = vec3(corBLF.x, -corBLF.y, corBLF.z);

    mCornersInit[kCOR_TopRight].nearPos = vec3(-corBLN.x, -corBLN.y, corBLN.z);
    mCornersInit[kCOR_TopRight].farPos  = vec3(-corBLF.x, -corBLF.y, corBLF.z);

    reset();
    calcPlanes();
}

void redraw()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);  // clear color, and reset the z-buffer
	glEnable(GL_DEPTH_TEST);                             // enable z-buffer test

	mat4x4 P = perspective(-1,1,-1,1,-1,-10);
	mat4x4 M = translation(0,0,-3)*rotation_z(angle)*rotation_y(2*angle);

	// Bind our vertices, texture, and GLSL program
	glBindBuffer(GL_ARRAY_BUFFER,mesh_vbo);
	glBindTexture(GL_TEXTURE_2D,texid);
	glUseProgram(program);

	// Initialize the GLSL uniform variables
	glUniformMatrix4fv(glGetUniformLocation(program,"P"),1,GL_TRUE,P.ptr());
	glUniformMatrix4fv(glGetUniformLocation(program,"M"),1,GL_TRUE,M.ptr());
	// Since our fragment shader also has a uniform (a 'sampler2D' texture index name 'texmap'),
	// we should tell our fragment shader that 'texmap' was bound to "texture unit 0" (the default)
	glUniform1i(glGetUniformLocation(program,"texmap"),0);

	int ploc = glGetAttribLocation(program,"p");  // index of position attribute in GLSL program
	int cloc = glGetAttribLocation(program,"c");  // index of colour attribute
	int tloc = glGetAttribLocation(program,"t");  // index of texcoord attribute

	// Each vertex contains a position, colour, and texcoord, so we must
	// tell OpenGL exactly how the memory of our vertex buffer is layed out.
	// sizeof(vertex) = 16 + 16 + 8 = 40 bytes
	//   position: "4 floats, 40 bytes apart, with offset 0 bytes"
	//   colour:   "4 floats, 40 bytes apart, with offset 16 bytes"
	//   colour:   "2 floats, 40 bytes apart, with offset 32 bytes"
	glVertexAttribPointer(ploc,4,GL_FLOAT,GL_FALSE,sizeof(vertex),OFFSET(vertex,p));
	glVertexAttribPointer(cloc,4,GL_FLOAT,GL_FALSE,sizeof(vertex),OFFSET(vertex,c));
	glVertexAttribPointer(tloc,2,GL_FLOAT,GL_FALSE,sizeof(vertex),OFFSET(vertex,t));
	glEnableVertexAttribArray(ploc); // don't forget to enable each one!
	glEnableVertexAttribArray(cloc);
	glEnableVertexAttribArray(tloc);

	// RASTERIZE!
	glDrawArrays(GL_TRIANGLE_STRIP,0,4);	
	
	// OPTIONAL
	glUseProgram(0);
	glBindBuffer(GL_ARRAY_BUFFER,0);

	glFlush();
}

void display()

{
  // WCS-to-VCS

  mat4 WCS_to_VCS
    = lookat( eyePosition, worldCentre, vec3(0,1,0) );

  // WCS-to-CCS

  float n = (eyePosition - worldCentre).length() - worldRadius;
  float f = (eyePosition - worldCentre).length() + worldRadius;

  mat4 WCS_to_CCS
    = perspective( fovy, windowWidth / (float) windowHeight, n, f )
    * WCS_to_VCS;

  // Light direction is in the WCS, but rotates

  vec3 lightDir(1,1.5,1);
  lightDir = lightDir.normalize();
  vec4 rotatedLightDir = rotate( theta, vec3(0,1,0) ) * vec4( lightDir, 0 );
  vec3 rotatedLightDir3 = vec3( rotatedLightDir.x, rotatedLightDir.y, rotatedLightDir.z );

  // Draw the objects

  renderer->render( objs, WCS_to_VCS, WCS_to_CCS, rotatedLightDir3, eyePosition );

  // Draw the world axes

  if (showAxes && !renderer->debugOn()) {
    mat4 axesTransform = WCS_to_CCS * scale( 10, 10, 10 );
    axes->draw( axesTransform, rotatedLightDir3 );
  }

  // Output status message

  char buffer[1000];
  renderer->makeStatusMessage( buffer );
  glColor3f(0.3,0.3,1.0);
  printString( buffer, 10, 10, windowWidth, windowHeight );

  // Done

  glutSwapBuffers();
}