OpenGL Programming Guide- Red Book 例子程序库 -系列- 1-Introduction to OpenGL-Part1

Example 1-1 : A Simple OpenGL Program

#include main() {OpenAWindowPlease(); glClearColor(0.0, 0.0, 0.0, 0.0); glClear(GL_COLOR_BUFFER_BIT); glColor3f(1.0, 1.0, 1.0); glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0); glBegin(GL_POLYGON); glVertex2f(-0.5, -0.5); glVertex2f(-0.5, 0.5); glVertex2f(0.5, 0.5); glVertex2f(0.5, -0.5); glEnd(); glFlush(); KeepTheWindowOnTheScreenForAWhile(); }


此程序无法编译通过,但把GL编程的核心内容和架构体现出来了
glClearColor(0.0, 0.0, 0.0, 0.0); glClear(GL_COLOR_BUFFER_BIT); glColor3f(1.0, 1.0, 1.0); glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0); glBegin(GL_POLYGON); glVertex2f(-0.5, -0.5); glVertex2f(-0.5, 0.5); glVertex2f(0.5, 0.5); glVertex2f(0.5, -0.5); glEnd(); glFlush();

以上代码结构在后续例子中将反复出现

Example 1-2 : A Simple OpenGL Program Using the Auxiliary Library: simple.c 原始程序
#include #include "aux.h"int main(int argc, char** argv) { auxInitDisplayMode (AUX_SINGLE | AUX_RGBA); auxInitPosition (0, 0, 500, 500); auxInitWindow (argv[0]); glClearColor (0.0, 0.0, 0.0, 0.0); glClear(GL_COLOR_BUFFER_BIT); glColor3f(1.0, 1.0, 1.0); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0); glBegin(GL_POLYGON); glVertex2f(-0.5, -0.5); glVertex2f(-0.5, 0.5); glVertex2f(0.5, 0.5); glVertex2f(0.5, -0.5); glEnd(); glFlush(); sleep(10); }

VC项目创建步骤 新建Win32 Console 项目

OpenGL Programming Guide- Red Book 例子程序库 -系列- 1-Introduction to OpenGL-Part1
文章图片

选择类型,建议选择2nd or 3rd

OpenGL Programming Guide- Red Book 例子程序库 -系列- 1-Introduction to OpenGL-Part1
文章图片
创建完毕的状态

OpenGL Programming Guide- Red Book 例子程序库 -系列- 1-Introduction to OpenGL-Part1
文章图片
复制例子原始代码,覆盖main函数所在cpp文件全部
OpenGL Programming Guide- Red Book 例子程序库 -系列- 1-Introduction to OpenGL-Part1
文章图片

第一轮编译错误
--------------------Configuration: Example_1_2 - Win32 Debug-------------------- Compiling... StdAfx.cpp Compiling... Example_1_2.cpp e:\openglrb\example_1_2\example_1_2.cpp(29) : fatal error C1010: unexpected end of file while looking for precompiled header directive Error executing cl.exe.Example_1_2.exe - 1 error(s), 0 warning(s)

解决方法,在 example_1_2.cpp的头部第一行包含stdafx.h

第二轮编译错误

--------------------Configuration: Example_1_2 - Win32 Debug-------------------- Compiling... Example_1_2.cpp c:\program files\microsoft visual studio\vc98\include\gl\gl.h(1152) : error C2144: syntax error : missing '; ' before type 'void' c:\program files\microsoft visual studio\vc98\include\gl\gl.h(1152) : error C2501: 'WINGDIAPI' : missing storage-class or type specifiers c:\program files\microsoft visual studio\vc98\include\gl\gl.h(1152) : fatal error C1004: unexpected end of file found Error executing cl.exe.Example_1_2.exe - 3 error(s), 0 warning(s)

百度搜索WINGDIAPI 可见该错误,原因是VC INCLUDE的gl.h文件是被Windows调整过的,和Qt开发库里面的gl.h内容上有区别
WINGDIAPI void APIENTRY glAccum (GLenum op, GLfloat value); WINGDIAPI void APIENTRY glAlphaFunc (GLenum func, GLclampf ref); WINGDIAPI GLboolean APIENTRY glAreTexturesResident (GLsizei n, const GLuint *textures, GLboolean *residences); WINGDIAPI void APIENTRY glArrayElement (GLint i); WINGDIAPI void APIENTRY glBegin (GLenum mode); WINGDIAPI void APIENTRY glBindTexture (GLenum target, GLuint texture); WINGDIAPI void APIENTRY glBitmap (GLsizei width, GLsizei height, GLfloat xorig, GLfloat yorig, GLfloat xmove, GLfloat ymove, const GLubyte *bitmap); WINGDIAPI void APIENTRY glBlendFunc (GLenum sfactor, GLenum dfactor); WINGDIAPI void APIENTRY glCallList (GLuint list);


此处解决方案: 在stdafx.h中增加包含 windows.h,如果在example_1_2.cpp中包含,需要在包含gl.h之前
第三轮编译错误
--------------------Configuration: Example_1_2 - Win32 Debug-------------------- Compiling... Example_1_2.cpp E:\OpenGLRB\Example_1_2\Example_1_2.cpp(6) : fatal error C1083: Cannot open include file: 'aux.h': No such file or directory Error executing cl.exe.Example_1_2.exe - 1 error(s), 0 warning(s)


没有aux.h,此文件已被更名为glaux.h,和gl.h在同一文件夹

OpenGL Programming Guide- Red Book 例子程序库 -系列- 1-Introduction to OpenGL-Part1
文章图片


此处解决方案: 将aux.h修改为GLAUX.H#include
至此cpp包含的头文件如下

#include "StdAfx.h" #include "windows.h" #include #include

第四轮编译错误

--------------------Configuration: Example_1_2 - Win32 Debug-------------------- Compiling... Example_1_2.cpp E:\OpenGLRB\Example_1_2\Example_1_2.cpp(28) : error C2065: 'sleep' : undeclared identifier E:\OpenGLRB\Example_1_2\Example_1_2.cpp(29) : warning C4508: 'main' : function should return a value; 'void' return type assumed Error executing cl.exe.Example_1_2.exe - 1 error(s), 1 warning(s)


解决方案, sleep函数首字母大写,main 函数结尾增加return 语句,或者将函数返回类型改为void, sleep(10)中的10是窗口生存时间,毫秒,需要改大一些
第五轮编译错误
--------------------Configuration: Example_1_2 - Win32 Debug-------------------- Compiling... Example_1_2.cpp Linking... Example_1_2.obj : error LNK2001: unresolved external symbol __imp__glFlush@0 Example_1_2.obj : error LNK2001: unresolved external symbol __imp__glEnd@0 Example_1_2.obj : error LNK2001: unresolved external symbol __imp__glVertex2f@8 Example_1_2.obj : error LNK2001: unresolved external symbol __imp__glBegin@4 Example_1_2.obj : error LNK2001: unresolved external symbol __imp__glOrtho@48 Example_1_2.obj : error LNK2001: unresolved external symbol __imp__glLoadIdentity@0 Example_1_2.obj : error LNK2001: unresolved external symbol __imp__glMatrixMode@4 Example_1_2.obj : error LNK2001: unresolved external symbol __imp__glColor3f@12 Example_1_2.obj : error LNK2001: unresolved external symbol __imp__glClear@4 Example_1_2.obj : error LNK2001: unresolved external symbol __imp__glClearColor@16 Example_1_2.obj : error LNK2001: unresolved external symbol _auxInitWindowA@4 Example_1_2.obj : error LNK2001: unresolved external symbol _auxInitPosition@16 Example_1_2.obj : error LNK2001: unresolved external symbol _auxInitDisplayMode@4 Debug/Example_1_2.exe : fatal error LNK1120: 13 unresolved externals Error executing link.exe.Example_1_2.exe - 14 error(s), 0 warning(s)


此处错误为链接错误,源文件的语法、拼写错误已解决
解决方案为引入OpenGL相关的lib文件

#pragma comment(lib,"opengl32.lib") #pragma comment(lib,"glaux.lib")


至此编译链接全部通过,当前main函数cpp文件内容如下
// Example_1_2.cpp : Defines the entry point for the console application. // #include "StdAfx.h" #include "windows.h" #include #include #pragma comment(lib,"opengl32.lib") #pragma comment(lib,"glaux.lib")int main(int argc, char** argv) { auxInitDisplayMode (AUX_SINGLE | AUX_RGBA); auxInitPosition (0, 0, 500, 500); auxInitWindow (argv[0]); glClearColor (0.0, 0.0, 0.0, 0.0); glClear(GL_COLOR_BUFFER_BIT); glColor3f(1.0, 1.0, 1.0); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0); glBegin(GL_POLYGON); glVertex2f(-0.5, -0.5); glVertex2f(-0.5, 0.5); glVertex2f(0.5, 0.5); glVertex2f(0.5, -0.5); glEnd(); glFlush(); Sleep(1000); return 0; }


运行截图 OpenGL Programming Guide- Red Book 例子程序库 -系列- 1-Introduction to OpenGL-Part1
文章图片
此截图需要将sleep参数调整足够大!




【OpenGL Programming Guide- Red Book 例子程序库 -系列- 1-Introduction to OpenGL-Part1】后记,本文针对第一章第二个例子给出了完整的编译排错流程,后续各例子将仅提供原始代码。调整后的代码、运行结果及必要的说明。


    推荐阅读