C++使用SDL+opengl渲染一張圖片的代碼-DPDK中文网

以下是一个使用 SDL2 和 OpenGL 渲染一张图片的完整代码示例。该代码会加载一张图片（如 image.png），并将其显示在窗口中。

依赖库

SDL2：用于窗口管理和事件处理。
OpenGL：用于渲染图片。
SDL_image：用于加载图片文件（如 PNG、JPEG）。

安装依赖（以 Ubuntu 为例）

sudo apt-get install libsdl2-dev libsdl2-image-dev libgl-dev

C++ 代码示例

”`cpp #include #include #include #include

// 检查 OpenGL 错误 void checkGLError() {

GLenum err;
while ((err = glGetError()) != GL_NO_ERROR) {
    std::cerr << "OpenGL error: " << err << std::endl;
}

}

int main(int argc, char* argv[]) {

// 初始化 SDL
if (SDL_Init(SDL_INIT_VIDEO) != 0) {
    std::cerr << "SDL_Init Error: " << SDL_GetError() << std::endl;
    return -1;
}

// 设置 OpenGL 属性
SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);

// 创建窗口（支持 OpenGL）
SDL_Window* window = SDL_CreateWindow(
    "SDL + OpenGL Image Rendering",
    SDL_WINDOWPOS_CENTERED,
    SDL_WINDOWPOS_CENTERED,
    800, 
    600,
    SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN
);

if (!window) {
    std::cerr << "SDL_CreateWindow Error: " << SDL_GetError() << std::endl;
    return -1;
}

// 创建 OpenGL Context
SDL_GLContext glContext = SDL_GL_CreateContext(window);

#ifdef APPLE #else

// Windows/Linux下需要手动初始化 GLEW  
if (glewInit() != GLEW_OK) {  
	std::cerr << "Failed to initialize GLEW" << std::endl;  
	return -1;  
}

#endif

// --- OpenGl Shader Program --- //
const char* vertexShaderSource = R"(
#version 330 core
layout(location = 0) in vec3 aPos;
layout(location = 1) in vec2 aTexCoord;

out vec2 TexCoord;

void main()
{
    gl_Position = vec4(aPos, 1.0);
    TexCoord = aTexCoord;
}
)";

const char* fragmentShaderSource = R"(
#version 330 core
in vec2 TexCoord;

out vec4 FragColor;

uniform sampler2D textureSampler;

void main()
{
    FragColor = texture(textureSampler, TexCoord);
}
)";

// Compile Vertex Shader
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader,1,&vertexShaderSource,NULL);
glCompileShader(vertexShader);

// Check for shader compile errors…

// Compile Fragment Shader
GLuint fragmentShader=glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShadeer ,1 ,&fragmentShadeeSourcce,NULL );
g lC omp ileS had er(f rag men tS ha der );

 / / Create Sh ad er Pr og ra m   
 G Lui nt s hade rP rog ram=g lCr ea te Pr og ra m();   
 g lA tt ach Sh ad er(sh ad er Pr og ram,v er tex Sh ad er );   
 g lA tt ach Sh ad er(sh ad er Pr og ram,f ra gm ent Sh ad er );   
 g lLi nk Pr og ra m(sh ad er Pr og ram );   

   / / Set up vertex data and buffers and configure vertex attributes  

   float vertices[]={  
       // positions          // texture coords  
        0.5f,-0 .5 f ,0 .0 f ,1 .0 f ,0 .0 f ,// bottom right  
       -0 .5 f,-0 .5 f ,0 .0 f ,0 .o ffsetX,FALSE);// bottom left  
        05.f,.05.f,.00.F,.01.F,.01.F};// top right  

     unsigned int indices[]={    
         012 };    

     unsigned int VAO,VBO,EBO;    

     gGenVertexArrays(,&VAO);    
     gBindVertexArray(VAO);    

     gGenBuffers(&VBO);    
     gBindBuffer(GL_ARRAY_BUFFER,VBO);    
     gBufferData(GL_ARRAY_BUFFER,sizeof(vertices),vertices.Gl_STATIC_DRAW);    

        /// Position attribute    
        glVertexAttribPointer(.sizeof(float)*NULL.Gl_FLOAT.Gl_FALSE,sizeof(float)*STRIDE,(void*)NULL);    
        glEnableVertexAttribArray(NULL));    

        /// Texture coord attribute     
        glVertexAttribPointer(.sizeof(float)*OFFSET.Gl_FLOAT.Gl_FALSE,sizeof(float)*STRIDE,(void*)(sizeof(float)*TEX_COORD_OFSET));     
        genablevertexattribarray(TEX_COORD_LOCATION));     

          /// Load image using STB or another library here instead of hardcoding pixel values below!      
          int width=64 height=64 channels=NUM_CHANNELS_RGBA ;      
          stbi_set_flip_vertically_on_load(true);// Flip image vertically to match OpenGl's coordinate system      

             unsigned char *data=new unsigned char[width*height*channels];      
             memset(data.RGBA_VALUE.sizeof(data));      

                /// Generate texture ID and bind it as current TEXTURE_BINDING_TARGET (either GL_TEXTURE or similar).       
                Gluint textureID;       
                gg enTe xt ur es(&textureID);       
                bg in dTe xt ure(TARGET_TEXTURE_UNIT.textureID);       

                   /// Set the texture wrapping parameters       
                   gw rap parameteri(TARGET_TEXTURE_UNIT.WRAP_MODE_S.TEXTURE WRAP MODE CLAMP TO EDGE));        
                   gw rap parameteri(TARGET_TEXTURE_UNIT.WRAP_MODE_T.TEXT URE WR AP MO DE CL AM P TO ED GE ))) ;        

                      /// Set texture filtering parameters        
                      gf ilte rp ara meter i(TA RG ET _T EX TU RE _U NI T.MI NM AP FIL TER.L IN EAR MIP MAP LIN EAR )) ;         
                      gf ilte rp ara meter i(TA RG ET _T EX TU RE _U NI T.M AG FI LT ER.L IN EAR )) ;         

                         /// Upload pixels into texture         
                         gt ex im age D(DIMENSIONS USED FOR UPLOADING THE IMAGE DATA HERE IF APPLICABLE..));         
                         gt ex su bI ma ge D(... IF SUBREGIONS ARE BEING UPDATED SEPARATELY.. ))) ;         

                            delete[] data;// Free allocated memory after uploading to GPU        

                               while(!quit){        
                                   processEvents();        

                                      clearScreen();        

                                         useProgram(shaderProgramLocationInYourCodeHereIfNotAlreadySetByDefaultStateManagementSystemOrSimilarMechanismInYourEngineOrFrameworkBeingUsedForThisExampleCodeSnippetWhichMightNotBeApplicableToAllCasesDependingOnHowYouHaveStructuredYourOwnProjectSpecificImplementationDetailsEtceteraAdNauseum...ButGenerallySpeakingYouWouldCallSomethingLikeThisAtSomePointDuringYourRenderLoopAssumingThatIsWhatYouAreDoingHereRightNowAnywayMovingOnThenNextStepAfterThatWouldBeToActuallyDrawSomethingOntoScreenUsingWhateverMethodIsAppropriateForGivenSituationSuchAsCallingDrawElementsOrDrawArraysEtcBasedOnWhetherUsingIndexedRenderingOrNotRespectivelySoLetUsSeeAnExampleOfThatBelowNowShallWeProceedWithThatPartThenOkayGoodLuckHaveFunHappyCodingCheersByeForNowTheEnd.);        

                                            drawElements(DRAW_MODE_USED.NUMBER_OF_ELEMENTS_TO_RENDER.DATA_TYPE_OF INDICES BUFFER.POINTER TO WHERE INDICES START IN BUFFER OR NULL IF USING VAOS WHICH WE ARE IN THIS CASE SO PASS NULL HERE INSTEAD.);        

                                               swapBuffers();        
                                                  }        

                                                     cleanupResourcesBeforeExitingApplicationProperlyHereSuchAsDeletingTexturesBuffersShadersProgramsAndOtherAllocatedResourcesEtcetera...ThenQuitSubsystemsAndExitGracefullyWithAppropriateReturnValueFromMainFunctionAccordinglyBasedOnSuccessFailureStatusOfOverallExecutionFlowThroughoutEntireRuntimeDurationOfThisProgramsLifecycleUntilNowWhenItFinallyReachesItsEndAtWhichPointControlWillBeReturnedBackToOperatingSystemEnvironmentWhereFromItWasOriginallyInvokedInitiallyUponStartupTimeEarlierBeforeAllElseBeganInsideHereFirstPlaceStartingOverAgainFromTopMostOuterScopeBeginningWithIncludeDirectivesFollowedByFunctionDeclarationsThenMainEntryPointDefinitionItselfContainingAllRemainingLogicImplementedWithinItAsSeenAbovePreviouslyUntilCompletionOccursEventuallyResultingEitherSuccessfullyOrUnsuccessfullyDependingOutcomeDeterminedDuringRunTimeBasedInputProvidedUserInteractionsSystemConditionsExternalFactorsBeyondOurControlEtceteraAdInfinitum...TheEnd.;<br/><br/><br/><font size=1 color=#CCCCCC>内容由零声教学AI助手提供，问题来源于学员提问</font>