使用opengl绘制三角形

1.之前在win编译时出现无法显示的情况,后来在linux测试调试是自已的笔记GPU垃圾,无法支持3.3版本,废了很久才找出原因,还是linux好调试程序

 

2.编写makefile

整个Demo

使用opengl绘制三角形_第1张图片

 

#  
CC      = g++
# -O2       : optimization option
# -s        : build small binary
# -mwindows : use this option to remove the popping cmd window
CCFLAGS = -O2 -Wall 
BIN     = Demo
RES     = 
OBJ     = shader.o start.o
# 项目Lib路径
CUBPATH = lib
# 项目头文件路径
CUCPATH = include
# 连接库文件
LIBS	=-L. -L$(CUBPATH) -lGL -lGLU -lGLEW -lglfw
INCLU	=-I$(CUCPATH) -I.
RM      =-rm

# 编译源码
.PHONY:$(BIN)
$(BIN): $(OBJ)
	$(CC) $(CCFLAGS) -o $(BIN) $^ $(INCLU) $(LIBS)  

shader.o:common/shader.cpp common/shader.hpp
	$(CC) $(CCFLAGS) -c $<

start.o:start.cpp
	$(CC) $(CCFLAGS) -c $<

# 清理,PHONY避免无依赖时被看成最终目标
.PHONY:clean
clean:
	$(RM) $(BIN) $(OBJ)

# 直接运行生成的文件
# .PHONY:run
run:$(BIN)
	chmod +x $(BIN)
	./$(BIN)


源码,来之官方3.3的教程

// Include standard headers
#include 
#include 

// Include GLEW
#include 

// Include GLFW
#include 
GLFWwindow* window;

// Include GLM
#include 
using namespace glm;

#include "common/shader.hpp"

int main( void )
{
    // Initialise GLFW
    if( !glfwInit() )
    {
        fprintf( stderr, "Failed to initialize GLFW\n" );
        return -1;
    }

    glfwWindowHint(GLFW_SAMPLES, 4);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    // Open a window and create its OpenGL context
    window = glfwCreateWindow( 1024, 768, "Tutorial 02 - Red triangle", NULL, NULL);
    if( window == NULL ){
        fprintf( stderr, "Failed to open GLFW window. If you have an Intel GPU, they are not 3.3 compatible. Try the 2.1 version of the tutorials.\n" );
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);

    // Initialize GLEW
    glewExperimental = true; // Needed for core profile
    if (glewInit() != GLEW_OK) {
        fprintf(stderr, "Failed to initialize GLEW\n");
        return -1;
    }

    // Ensure we can capture the escape key being pressed below
    glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);

    // Dark blue background
    glClearColor(0.0f, 0.0f, 0.4f, 0.0f);

    GLuint VertexArrayID;
    glGenVertexArrays(1, &VertexArrayID);
    glBindVertexArray(VertexArrayID);

    // Create and compile our GLSL program from the shaders
    GLuint programID = LoadShaders( "SimpleVertexShader.vertexshader", "SimpleFragmentShader.fragmentshader" );


    static const GLfloat g_vertex_buffer_data[] = { 
        -1.0f, -1.0f, 0.0f,
         1.0f, -1.0f, 0.0f,
         0.0f,  1.0f, 0.0f,
    };

    GLuint vertexbuffer;
    glGenBuffers(1, &vertexbuffer);
    glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
    glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW);

    do{

        // Clear the screen
        glClear( GL_COLOR_BUFFER_BIT );

        // Use our shader
        glUseProgram(programID);

        // 1rst attribute buffer : vertices
        glEnableVertexAttribArray(0);
        glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
        glVertexAttribPointer(
            0,                  // attribute 0. No particular reason for 0, but must match the layout in the shader.
            3,                  // size
            GL_FLOAT,           // type
            GL_FALSE,           // normalized?
            0,                  // stride
            (void*)0            // array buffer offset
        );

        // Draw the triangle !
        glDrawArrays(GL_TRIANGLES, 0, 3); // 3 indices starting at 0 -> 1 triangle

        glDisableVertexAttribArray(0);

        // Swap buffers
        glfwSwapBuffers(window);
        glfwPollEvents();

    } // Check if the ESC key was pressed or the window was closed
    while( glfwGetKey(window, GLFW_KEY_ESCAPE ) != GLFW_PRESS &&
           glfwWindowShouldClose(window) == 0 );

    // Cleanup VBO
    glDeleteBuffers(1, &vertexbuffer);
    glDeleteVertexArrays(1, &VertexArrayID);
    glDeleteProgram(programID);

    // Close OpenGL window and terminate GLFW
    glfwTerminate();

    return 0;
}

图片来之官方的,由于笔记不支持,又不想用2.+的,只能..

使用opengl绘制三角形_第2张图片

 

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