在Lua脚本中使用OpenGL函数

主要因为单纯的学习Lua太枯燥了，所以先学些了Lua基本语法然后就直接学习了与C语言的相互调用，所以以后的OpenGL代码都用Lua写，这样更容易理解Lua以及提高学习兴趣。下面是这2天的代码包括C语言部分和Lua部分，因为公司环境是Ubuntu的所以我用glut库使代码在Linux和windows下都可以使用。

C语言代码如下：

#include <GL/gl.h> #include <GL/glu.h> #include <GL/glut.h> #include <lua.h> #include <lauxlib.h> #include <lualib.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include "pqimage.h" #define CAST(x,t) ((t)(x)) #define ERROR(...) printf(__VA_ARGS__);exit(0) #define HAVE_BUFFER #if defined(HAVE_BUFFER) #define DISPLAY_MODE GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA #define ShowGL() glutSwapBuffers() #else #define DISPLAY_MODE GLUT_SINGLE | GLUT_RGB #define ShowGL() glFlush() #endif int load_texture(const char *filename) { GLuint texture; PQ_RGBImageRec *tex_img = pqDIBImageLoad(filename); if ( !tex_img ) return 0; glGenTextures(1,&texture); glBindTexture(GL_TEXTURE_2D,texture); glTexImage2D(GL_TEXTURE_2D,3,tex_img->width,tex_img->height,GL_RGB,GL_UNSIGNED_BYTE,tex_img->buf); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR); pqDIBImageFree(tex_img); return (int)texture; } //******************************************************************************** //*********************************** Lua **************************************** //******************************************************************************** int Flip(lua_State *L) { ShowGL(); return 0; } int LoadTexture(lua_State *L) { const char * filename = luaL_checkstring(L,1); lua_pushnumber(L,load_texture(filename)); return 1; } int glLoadIdentity_lua(lua_State *L) { glLoadIdentity(); return 0; } int glTranslatef_lua(lua_State *L) { GLfloat x = (GLfloat)luaL_checknumber(L,1); GLfloat y = (GLfloat)luaL_checknumber(L,2); GLfloat z = (GLfloat)luaL_checknumber(L,3); glTranslatef(x,y,z); return 0; } int glRotatef_lua(lua_State *L) { GLfloat angle = (GLfloat)luaL_checknumber(L,1); GLfloat x = (GLfloat)luaL_checknumber(L,2); GLfloat y = (GLfloat)luaL_checknumber(L,3); GLfloat z = (GLfloat)luaL_checknumber(L,4); glRotatef(angle,x,z); return 0; } int glVertex3f_lua(lua_State *L) { GLfloat x = (GLfloat)luaL_checknumber(L,3); glVertex3f(x,z); return 0; } int glColor3f_lua(lua_State *L) { GLfloat x = (GLfloat)luaL_checknumber(L,3); glColor3f(x,z); return 0; } int glTexCoord2f_lua(lua_State *L) { GLfloat x = (GLfloat)luaL_checknumber(L,2); glTexCoord2f(x,y); return 0; } int glBegin_lua(lua_State *L) { GLuint mode = (GLuint)luaL_checknumber(L,1); glBegin(mode); return 0; } int glEnd_lua(lua_State *L) { glEnd(); return 0; } int glBindTexture_lua(lua_State *L) { GLuint mode = (GLuint)luaL_checknumber(L,1); GLuint tex = (GLuint)luaL_checknumber(L,2); glBindTexture(mode,tex); return 0; } int glEnable_lua(lua_State *L) { GLuint mode = (GLuint)luaL_checknumber(L,1); glEnable(mode); return 0; } int glDisable_lua(lua_State *L) { GLuint mode = (GLuint)luaL_checknumber(L,1); glDisable(mode); return 0; } int glShadeModel_lua(lua_State *L) { GLuint mode = (GLuint)luaL_checknumber(L,1); glShadeModel(mode); return 0; } int glClearColor_lua(lua_State *L) { GLfloat r = (GLfloat)luaL_checknumber(L,1); GLfloat g = (GLfloat)luaL_checknumber(L,2); GLfloat b = (GLfloat)luaL_checknumber(L,3); GLfloat a = (GLfloat)luaL_checknumber(L,4); glClearColor(r,g,b,a); return 0; } int glClearDepth_lua(lua_State *L) { GLfloat d = (GLfloat)luaL_checknumber(L,1); glClearDepth(d); return 0; } int glDepthFunc_lua(lua_State *L) { GLfloat mode = (GLfloat)luaL_checknumber(L,1); glDepthFunc(mode); return 0; } int glHint_lua(lua_State *L) { GLfloat m1 = (GLfloat)luaL_checknumber(L,1); GLfloat m2 = (GLfloat)luaL_checknumber(L,2); glHint(m1,m2); return 0; } int glViewport_lua(lua_State *L) { GLfloat left = (GLfloat)luaL_checknumber(L,1); GLfloat top = (GLfloat)luaL_checknumber(L,2); GLfloat right = (GLfloat)luaL_checknumber(L,3); GLfloat bottom = (GLfloat)luaL_checknumber(L,4); glViewport(left,top,right,bottom); return 0; } int glMatrixMode_lua(lua_State *L) { GLuint mode = (GLuint)luaL_checknumber(L,1); glMatrixMode(mode); return 0; } int gluPerspective_lua(lua_State *L) { GLfloat angle = (GLfloat)luaL_checknumber(L,1); GLfloat fwh = (GLfloat)luaL_checknumber(L,2); GLfloat far = (GLfloat)luaL_checknumber(L,3); GLfloat near = (GLfloat)luaL_checknumber(L,4); gluPerspective(angle,fwh,far,near); return 0; } int glClear_lua(lua_State *L) { GLuint mode = (GLuint)luaL_checknumber(L,1); glClear(mode); return 0; } int EndProcess(lua_State *L) { GLint no = (GLint)luaL_checknumber(L,1); exit(no); return 0; } int getfield(lua_State *L,const char *key) { int result; lua_pushstring(L,key); lua_gettable(L,-2); /* 这里调用完后key的值会被弹出，然后才压入table.key的值到栈顶 */ result = lua_isnumber(L,-1) ? (int)lua_tonumber(L,-1) : 0; lua_pop(L,1); return result; } const char * getfield_str(lua_State *L,const char *key) { const char * result = NULL; lua_pushstring(L,-2); /* 这里调用完后key的值会被弹出，然后才压入table.key的值到栈顶 */ result = lua_isstring(L,-1) ? lua_tostring(L,-1) : NULL; lua_pop(L,1); return result; } //******************************************************************************** //*********************************** Lua **************************************** //******************************************************************************** static lua_State *G_L = NULL; static GLint S_wnd_w = 0; static GLint S_wnd_h = 0; static char * S_caption = NULL; void init_global(const char *lua_file) { G_L = lua_open(); luaL_openlibs(G_L); lua_register(G_L,"Flip",Flip); lua_register(G_L,"EndProcess",EndProcess); lua_register(G_L,"LoadTexture",LoadTexture); lua_register(G_L,"glLoadIdentity",glLoadIdentity_lua); lua_register(G_L,"glTranslatef",glTranslatef_lua); lua_register(G_L,"glRotatef",glRotatef_lua); lua_register(G_L,"glVertex3f",glVertex3f_lua); lua_register(G_L,"glColor3f",glColor3f_lua); lua_register(G_L,"glTexCoord2f",glTexCoord2f_lua); lua_register(G_L,"glBegin",glBegin_lua); lua_register(G_L,"glEnd",glEnd_lua); lua_register(G_L,"glBindTexture",glBindTexture_lua); lua_register(G_L,"glEnable",glEnable_lua); lua_register(G_L,"glDisable",glDisable_lua); lua_register(G_L,"glShadeModel",glShadeModel_lua); lua_register(G_L,"glClearColor",glClearColor_lua); lua_register(G_L,"glClearDepth",glClearDepth_lua); lua_register(G_L,"glDepthFunc",glDepthFunc_lua); lua_register(G_L,"glHint",glHint_lua); lua_register(G_L,"glViewport",glViewport_lua); lua_register(G_L,"glMatrixMode",glMatrixMode_lua); lua_register(G_L,"gluPerspective",gluPerspective_lua); lua_register(G_L,"glClear",glClear_lua); lua_pushnumber(G_L,GL_COLOR_BUFFER_BIT); lua_setglobal(G_L,"GL_COLOR_BUFFER_BIT"); lua_pushnumber(G_L,GL_DEPTH_BUFFER_BIT); lua_setglobal(G_L,"GL_DEPTH_BUFFER_BIT"); lua_pushnumber(G_L,GL_QUADS); lua_setglobal(G_L,"GL_QUADS"); lua_pushnumber(G_L,GL_TRIANGLES); lua_setglobal(G_L,"GL_TRIANGLES"); lua_pushnumber(G_L,GL_LINES); lua_setglobal(G_L,"GL_LINES"); lua_pushnumber(G_L,GL_TEXTURE_2D); lua_setglobal(G_L,"GL_TEXTURE_2D"); lua_pushnumber(G_L,GL_PROJECTION); lua_setglobal(G_L,"GL_PROJECTION"); lua_pushnumber(G_L,GL_MODELVIEW); lua_setglobal(G_L,"GL_MODELVIEW"); lua_pushnumber(G_L,GL_SMOOTH); lua_setglobal(G_L,"GL_SMOOTH"); lua_pushnumber(G_L,GL_DEPTH_TEST); lua_setglobal(G_L,"GL_DEPTH_TEST"); lua_pushnumber(G_L,GL_LEQUAL); lua_setglobal(G_L,"GL_LEQUAL"); lua_pushnumber(G_L,GL_PERSPECTIVE_CORRECTION_HINT); lua_setglobal(G_L,"GL_PERSPECTIVE_CORRECTION_HINT"); lua_pushnumber(G_L,GL_NICEST); lua_setglobal(G_L,"GL_NICEST"); lua_pushnumber(G_L,GLUT_LEFT_BUTTON); lua_setglobal(G_L,"GLUT_LEFT_BUTTON"); lua_pushnumber(G_L,GLUT_MIDDLE_BUTTON); lua_setglobal(G_L,"GLUT_MIDDLE_BUTTON"); lua_pushnumber(G_L,GLUT_RIGHT_BUTTON); lua_setglobal(G_L,"GLUT_RIGHT_BUTTON"); lua_pushnumber(G_L,GLUT_DOWN); lua_setglobal(G_L,"GLUT_DOWN"); lua_pushnumber(G_L,GLUT_UP); lua_setglobal(G_L,"GLUT_UP"); if ( luaL_loadfile(G_L,lua_file) ) { ERROR("load %s failed!/n[error] %s/n",lua_file,lua_tostring(G_L,-1)); } if ( lua_pcall(G_L,0) ) { ERROR("the %s has error!/n [error] %s/n",-1)); } lua_getglobal(G_L,"Screen"); S_wnd_w = getfield(G_L,"width"); S_wnd_h = getfield(G_L,"height"); const char *title = getfield_str(G_L,"caption"); int len = strlen(title); if ( !(S_caption = (char *)malloc(len+1)) ) { ERROR("alloc caption memory space failed!/n"); } memcpy(S_caption,title,len); S_caption[len] = '/0'; } int init() { lua_getglobal(G_L,"init"); if ( lua_pcall(G_L,0) ) { ERROR("call lua.init failed!/n[error] %s/n",-1)); } } void mouse(int button,int state,int x,int y) { lua_getglobal(G_L,"mouse"); lua_pushnumber(G_L,button); lua_pushnumber(G_L,state); lua_pushnumber(G_L,x); lua_pushnumber(G_L,y); if ( lua_pcall(G_L,4,0) ) { ERROR("call lua.mouse failed!/n[error] %s/n",-1)); } } void active_motion(int x,"active_motion"); lua_pushnumber(G_L,2,0) ) { ERROR("call lua.active_motion failed!/n[error] %s/n",-1)); } } void passive_motion(int x,"passive_motion"); lua_pushnumber(G_L,0) ) { ERROR("call lua.passive_motion failed!/n[error] %s/n",-1)); } } void keyboard(unsigned char key,"keyboard"); lua_pushnumber(G_L,key); lua_pushnumber(G_L,0) ) { ERROR("call lua.keyboard failed!/n[error] %s/n",-1)); } } void reshape(int w,int h) { lua_getglobal(G_L,"reshape"); lua_pushnumber(G_L,w); lua_pushnumber(G_L,h); if ( lua_pcall(G_L,0) ) { ERROR("call lua.reshape failed!/n[error] %s/n",-1)); } } void display() { lua_getglobal(G_L,"display"); if ( lua_pcall(G_L,0) ) { ERROR("call lua.display failed!/n[error] %s/n",-1)); } } void release() { lua_close(G_L); } int main(int argc,char *argv[]) { if ( argc > 1 ) { init_global(argv[1]); if ( argc > 2 ) printf("too many parameters!/n"); } else { ERROR("too less parameter!/n"); } glutInit(&argc,argv); glutInitDisplayMode(DISPLAY_MODE); glutInitWindowPosition(0,0); glutInitWindowSize(S_wnd_w,S_wnd_h); glutCreateWindow(S_caption); init(); glutMouseFunc(mouse); glutMotionFunc(active_motion); glutPassiveMotionFunc(passive_motion); glutKeyboardFunc(keyboard); glutReshapeFunc(reshape); glutDisplayFunc(display); glutIdleFunc(display); glutMainLoop(); release(); return 0; }

Lua代码如下：

Screen = {width = 600,height = 600,caption = "OpenGL - Lua"} -- 常用颜色 F_BLACK = {r=0.0,g=0.0,b=0.0} F_BLACK_A = {r=0.0,b=0.0,a=0.0} F_WHITE = {r=0.0,b=0.0} F_WHITE_A = {r=1.0,g=1.0,b=1.0,a=0.0} F_RED = {r=1.0,b=0.0} F_RED_A = {r=1.0,a=0.0} F_GREEN = {r=0.0,b=0.0} F_GREEN_A = {r=0.0,a=0.0} F_BLUE = {r=0.0,b=1.0}; F_BLUE_A = {r=0.0,a=0.0} -- 局部变量 local cube_vertexs = { {x = -1.0,y = -1.0,z = 1.0},-- 1 {x = 1.0,-- 2 {x = 1.0,y = 1.0,-- 3 {x = -1.0,-- 4 {x = 1.0,z = -1.0},-- 5 {x = -1.0,-- 6 {x = -1.0,-- 7 {x = 1.0,z = -1.0} -- 8 } local standard_cube = { front = {cube_vertexs[1],cube_vertexs[2],cube_vertexs[3],cube_vertexs[4]},back = {cube_vertexs[5],cube_vertexs[6],cube_vertexs[7],cube_vertexs[8]},up = {cube_vertexs[4],cube_vertexs[8],cube_vertexs[7]},bottom = {cube_vertexs[1],cube_vertexs[5],cube_vertexs[6]},left = {cube_vertexs[6],cube_vertexs[1],cube_vertexs[4],right = {cube_vertexs[2],cube_vertexs[3]} } local cubes = { { image_file = "tex.bmp",texture = 0,x = 0,y = 0,r = 1.0,coord = {} },{ image_file = "tex2.bmp",coord = {} } } local rot_x = 0.0 local rot_y = 0.0 local rot_z = 0.0 local zoom = -8.0 local trans_x = 0.0 local trans_y = 0.0 local b_mousedown = false local mousedown_x = 0 local mousedown_y = 0 -- 初始化cube function initCube() for i,v in ipairs(cubes) do v.x = -1.0 + (i-1)*2.0 v.y = 0.0 v.coord = standard_cube v.texture = LoadTexture(v.image_file) if v.texture == 0 then print("load texture " .. v.image_file .. " failed!/n") EndProcess(0) end end end -- 初始化 function init() initCube() glEnable(GL_TEXTURE_2D) glShadeModel(GL_SMOOTH) glClearColor(F_BLACK_A.r,F_BLACK_A.g,F_BLACK_A.b,F_BLACK_A.a) glClearDepth(1.0) glEnable(GL_DEPTH_TEST) glDepthFunc(GL_LEQUAL) glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST) end -- 显示 function display() glClear(GL_COLOR_BUFFER_BIT) glClear(GL_DEPTH_BUFFER_BIT) for _,v in ipairs(cubes) do glLoadIdentity() glTranslatef(trans_x+v.x,trans_y+v.y,zoom) glRotatef(rot_x,1.0,0.0,0.0) glRotatef(rot_y,0.0) glRotatef(rot_z,1.0) glBindTexture(GL_TEXTURE_2D,v.texture) glBegin(GL_QUADS) glTexCoord2f(0.0,0.0); glVertex3f(v.coord.front[1].x,v.coord.front[1].y,v.coord.front[1].z) glTexCoord2f(1.0,0.0); glVertex3f(v.coord.front[2].x,v.coord.front[2].y,v.coord.front[2].z) glTexCoord2f(1.0,1.0); glVertex3f(v.coord.front[3].x,v.coord.front[3].y,v.coord.front[3].z) glTexCoord2f(0.0,1.0); glVertex3f(v.coord.front[4].x,v.coord.front[4].y,v.coord.front[4].z) glTexCoord2f(0.0,0.0); glVertex3f(v.coord.back[1].x,v.coord.back[1].y,v.coord.back[1].z) glTexCoord2f(1.0,0.0); glVertex3f(v.coord.back[2].x,v.coord.back[2].y,v.coord.back[2].z) glTexCoord2f(1.0,1.0); glVertex3f(v.coord.back[3].x,v.coord.back[3].y,v.coord.back[3].z) glTexCoord2f(0.0,1.0); glVertex3f(v.coord.back[4].x,v.coord.back[4].y,v.coord.back[4].z) glTexCoord2f(0.0,0.0); glVertex3f(v.coord.up[1].x,v.coord.up[1].y,v.coord.up[1].z) glTexCoord2f(1.0,0.0); glVertex3f(v.coord.up[2].x,v.coord.up[2].y,v.coord.up[2].z) glTexCoord2f(1.0,1.0); glVertex3f(v.coord.up[3].x,v.coord.up[3].y,v.coord.up[3].z) glTexCoord2f(0.0,1.0); glVertex3f(v.coord.up[4].x,v.coord.up[4].y,v.coord.up[4].z) glTexCoord2f(0.0,0.0); glVertex3f(v.coord.bottom[1].x,v.coord.bottom[1].y,v.coord.bottom[1].z) glTexCoord2f(1.0,0.0); glVertex3f(v.coord.bottom[2].x,v.coord.bottom[2].y,v.coord.bottom[2].z) glTexCoord2f(1.0,1.0); glVertex3f(v.coord.bottom[3].x,v.coord.bottom[3].y,v.coord.bottom[3].z) glTexCoord2f(0.0,1.0); glVertex3f(v.coord.bottom[4].x,v.coord.bottom[4].y,v.coord.bottom[4].z) glTexCoord2f(0.0,0.0); glVertex3f(v.coord.left[1].x,v.coord.left[1].y,v.coord.left[1].z) glTexCoord2f(1.0,0.0); glVertex3f(v.coord.left[2].x,v.coord.left[2].y,v.coord.left[2].z) glTexCoord2f(1.0,1.0); glVertex3f(v.coord.left[3].x,v.coord.left[3].y,v.coord.left[3].z) glTexCoord2f(0.0,1.0); glVertex3f(v.coord.left[4].x,v.coord.left[4].y,v.coord.left[4].z) glTexCoord2f(0.0,0.0); glVertex3f(v.coord.right[1].x,v.coord.right[1].y,v.coord.right[1].z) glTexCoord2f(1.0,0.0); glVertex3f(v.coord.right[2].x,v.coord.right[2].y,v.coord.right[2].z) glTexCoord2f(1.0,1.0); glVertex3f(v.coord.right[3].x,v.coord.right[3].y,v.coord.right[3].z) glTexCoord2f(0.0,1.0); glVertex3f(v.coord.right[4].x,v.coord.right[4].y,v.coord.right[4].z) glEnd() end rot_x = rot_x + 0.02 rot_y = rot_y + 0.03 rot_z = rot_z + 0.04 rot_x = ((rot_x > 360.0) and (rot_x - 360.0)) or rot_x rot_y = ((rot_y > 360.0) and (rot_y - 360.0)) or rot_y rot_z = ((rot_z > 360.0) and (rot_z - 360.0)) or rot_z Flip() end -- 窗口大小改变 function reshape(w,h) if h == 0 then h = 1 end glViewport(0,w,h) glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(45.0,w/h,0.1,100.0) glMatrixMode(GL_MODELVIEW) glLoadIdentity() end -- 鼠标点击事件 function mouse(button,state,y) if button == GLUT_LEFT_BUTTON then if state == GLUT_DOWN then if not b_mousedown then b_mousedown = true mousedown_x = x mousedown_y = y end elseif state == GLUT_up then if b_mousedown then b_mousedown = false end end elseif button == GLUT_RIGHT_BUTTON then trans_x = 0.0 trans_y = 0.0 end end -- 鼠标移动事件(鼠标按下时移动) function active_motion(x,y) if b_mousedown then local tx = (x-mousedown_x)/Screen.width*zoom local ty = (mousedown_y-y)/Screen.height*zoom trans_x = trans_x - tx trans_y = trans_y - ty mousedown_x = x mousedown_y = y end end -- 鼠标移动事件(鼠标没有按下时移动) function passive_motion(x,y) -- print(x,y) end -- 键盘事件 function keyboard(key,y) if key == 27 then EndProcess(0) end end

在linux下先安装编译lua(这中间还需要下载安装readline5库)，然后用 gcc -o luaGL luaGL.c -lglut -lGLU -lGL -llua -ldl -lm编译即可，运行luaGL + 指定lua即可

在windows下在代码中添加:

#pragma comment(lib,“opengl32.lib")

#pragma comment(lib,"glu32.lib")

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

#pragma comment(lib,"lua.lib")

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这些只是供大家参考，如果大家有兴趣可以把完整的OpenGL库都加进来（我想这样的话，不如直接使用C语言了），我主要是为了学习Lua的时候更有兴趣，不然单写些书上的例子程序太枯燥了，大家还可以试着把socket库也添加进来（luasocket这个库好像也可以），反正发挥你们的想象吧。

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注: 因为linux下的OpenGL没有aux库，所以写了一个简单的图片解析库pqimage，只解析bmp图片，功能和auxDIBImageLoad一样。