在Lua腳本中使用OpenGL函數

主要因爲單純的學習Lua太枯燥了，所以先學些了Lua基本語法然後就直接學習了與C語言的相互調用，所以以後的OpenGL代碼都用Lua寫，這樣更容易理解Lua以及提高學習興趣。下面是這2天的代碼包括C語言部分和Lua部分，因爲公司環境是Ubuntu的所以我用glut庫使代碼在Linux和windows下都可以使用。

C語言代碼如下：

#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, 0, 3, tex_img->width, tex_img->height, 0, 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, y, z); return 0; } int glVertex3f_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); glVertex3f(x, y, z); return 0; } int glColor3f_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); glColor3f(x, y, z); return 0; } int glTexCoord2f_lua(lua_State *L) { GLfloat x = (GLfloat)luaL_checknumber(L, 1); GLfloat y = (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); /* 這裏調用完後key的值會被彈出，然後才壓入table.key的值到棧頂 */ 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, key); lua_gettable(L, -2); /* 這裏調用完後key的值會被彈出，然後才壓入table.key的值到棧頂 */ 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, 0, 0) ) { ERROR("the %s has error!/n [error] %s/n", lua_file, lua_tostring(G_L, -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, 0, 0) ) { ERROR("call lua.init failed!/n[error] %s/n", lua_tostring(G_L, -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, 0) ) { ERROR("call lua.mouse failed!/n[error] %s/n", lua_tostring(G_L, -1)); } } void active_motion(int x, int y) { lua_getglobal(G_L, "active_motion"); lua_pushnumber(G_L, x); lua_pushnumber(G_L, y); if ( lua_pcall(G_L, 2, 0, 0) ) { ERROR("call lua.active_motion failed!/n[error] %s/n", lua_tostring(G_L, -1)); } } void passive_motion(int x, int y) { lua_getglobal(G_L, "passive_motion"); lua_pushnumber(G_L, x); lua_pushnumber(G_L, y); if ( lua_pcall(G_L, 2, 0, 0) ) { ERROR("call lua.passive_motion failed!/n[error] %s/n", lua_tostring(G_L, -1)); } } void keyboard(unsigned char key, int x, int y) { lua_getglobal(G_L, "keyboard"); lua_pushnumber(G_L, key); lua_pushnumber(G_L, x); lua_pushnumber(G_L, y); if ( lua_pcall(G_L, 3, 0, 0) ) { ERROR("call lua.keyboard failed!/n[error] %s/n", lua_tostring(G_L, -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, 2, 0, 0) ) { ERROR("call lua.reshape failed!/n[error] %s/n", lua_tostring(G_L, -1)); } } void display() { lua_getglobal(G_L, "display"); if ( lua_pcall(G_L, 0, 0, 0) ) { ERROR("call lua.display failed!/n[error] %s/n", lua_tostring(G_L, -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代碼如下：

Screen = {width = 600, height = 600, caption = "OpenGL - Lua"} -- 常用顏色 F_BLACK = {r=0.0, g=0.0, b=0.0} F_BLACK_A = {r=0.0, g=0.0, b=0.0, a=0.0} F_WHITE = {r=0.0, g=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, g=0.0, b=0.0} F_RED_A = {r=1.0, g=0.0, b=0.0, a=0.0} F_GREEN = {r=0.0, g=1.0, b=0.0} F_GREEN_A = {r=0.0, g=1.0, b=0.0, a=0.0} F_BLUE = {r=0.0, g=0.0, b=1.0}; F_BLUE_A = {r=0.0, g=0.0, b=1.0, a=0.0} -- 局部變量 local cube_vertexs = { {x = -1.0, y = -1.0, z = 1.0}, -- 1 {x = 1.0, y = -1.0, z = 1.0}, -- 2 {x = 1.0, y = 1.0, z = 1.0}, -- 3 {x = -1.0, y = 1.0, z = 1.0}, -- 4 {x = 1.0, y = -1.0, z = -1.0}, -- 5 {x = -1.0, y = -1.0, z = -1.0}, -- 6 {x = -1.0, y = 1.0, z = -1.0}, -- 7 {x = 1.0, y = 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[3], cube_vertexs[8], cube_vertexs[7]}, bottom = {cube_vertexs[1], cube_vertexs[2], cube_vertexs[5], cube_vertexs[6]}, left = {cube_vertexs[6], cube_vertexs[1], cube_vertexs[4], cube_vertexs[7]}, right = {cube_vertexs[2], cube_vertexs[5], cube_vertexs[8], cube_vertexs[3]} } local cubes = { { image_file = "tex.bmp", texture = 0, x = 0, y = 0, r = 1.0, coord = {} }, { image_file = "tex2.bmp", texture = 0, x = 0, y = 0, r = 1.0, 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 -- 顯示 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, 1.0, 0.0) glRotatef(rot_z, 0.0, 0.0, 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 -- 窗口大小改變 function reshape(w, h) if h == 0 then h = 1 end glViewport(0, 0, w, h) glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(45.0, w/h, 0.1, 100.0) glMatrixMode(GL_MODELVIEW) glLoadIdentity() end -- 鼠標點擊事件 function mouse(button, state, x, 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 -- 鼠標移動事件(鼠標按下時移動) 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 -- 鼠標移動事件(鼠標沒有按下時移動) function passive_motion(x, y) -- print(x, y) end -- 鍵盤事件 function keyboard(key, x, y) if key == 27 then EndProcess(0) end end

在linux下先安裝編譯lua(這中間還需要下載安裝readline5庫)，然後用 gcc -o luaGL luaGL.c -lglut -lGLU -lGL -llua -ldl -lm編譯即可，運行luaGL + 指定lua即可

在windows下在代碼中添加:

#pragma comment(lib, “opengl32.lib")

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

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

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

 

這些只是供大家參考，如果大家有興趣可以把完整的OpenGL庫都加進來（我想這樣的話，不如直接使用C語言了），我主要是爲了學習Lua的時候更有興趣，不然單寫些書上的例子程序太枯燥了，大家還可以試着把socket庫也添加進來（luasocket這個庫好像也可以），反正發揮你們的想象吧。

 

注: 因爲linux下的OpenGL沒有aux庫，所以寫了一個簡單的圖片解析庫pqimage，只解析bmp圖片，功能和auxDIBImageLoad一樣。