/*
????fog.c
????Nate?Robins?1997

????Tool?for?teaching?about?OpenGL?fog.
????
*/


#include?
#include?
#include?
#include?
#include?
#include?“glm.h“


typedef?struct?_cell?{
????int?id;
????int?x?y;
????float?min?max;
????float?value;
????float?step;
????char*?info;
????char*?format;
}?cell;


cell?color[4]?=?{
????{?1?180?40?0.0?1.0?0.7?0.005
????????“Specifies?red?component?of?fog?color.“?“%.2f“?}
????{?2?240?40?0.0?1.0?0.7?0.005?
????“Specifies?green?component?of?fog?color.“?“%.2f“?}
????{?3?300?40?0.0?1.0?0.7?0.005?
????“Specifies?blue?component?of?fog?color.“?“%.2f“?}
????{?4?360?40?0.0?1.0?1.0?0.005?
????“Specifies?alpha?component?of?fog?color.“?“%.2f“?}
};

cell?density?=?{?5?260?120??0.0?3.0?1.0?0.01?
“Specifies?the?near?distance.“?“%.2f“?};
cell?fstart??=?{?6?240?120?-3.0?3.0?0.5?0.01?
“Specifies?the?far?distance.“?“%.2f“?};
cell?fend????=?{?7?240?160?-3.0?3.0?2.0?0.01
“Specifies?the?fog?density.“?“%.2f“?};

GLenum?mode?=?GL_LINEAR;

GLboolean?clear?=?GL_TRUE;
GLMmodel*?pmodel?=?NULL;


GLfloat?eye[3]?=?{?0.5?0.25?1.5?};
GLfloat?at[3]??=?{?0.0?-0.25?0.0?};
GLfloat?up[3]??=?{?0.0?1.0?0.0?};

void?redisplay_all（void）;
GLuint?window?world?screen?command;
GLuint?sub_width?=?256?sub_height?=?256;
GLint?selection?=?0;


GLvoid?*font_style?=?GLUT_BITMAP_TIMES_ROMAN_10;

void
setfont（char*?name?int?size）
{
????font_style?=?GLUT_BITMAP_HELVETICA_10;
????if?（strcmp（name?“helvetica“）?==?0）?{
????????if?（size?==?12）?
????????????font_style?=?GLUT_BITMAP_HELVETICA_12;
????????else?if?（size?==?18）
????????????font_style?=?GLUT_BITMAP_HELVETICA_18;
????}?else?if?（strcmp（name?“times?roman“）?==?0）?{
????????font_style?=?GLUT_BITMAP_TIMES_ROMAN_10;
????????if?（size?==?24）
????????????font_style?=?GLUT_BITMAP_TIMES_ROMAN_24;
????}?else?if?（strcmp（name?“8x13“）?==?0）?{
????????font_style?=?GLUT_BITMAP_8_BY_13;
????}?else?if?（strcmp（name?“9x15“）?==?0）?{
????????font_style?=?GLUT_BITMAP_9_BY_15;
????}
}

void?
drawstr（GLuint?x?GLuint?y?char*?format?...）
{
????va_list?args;
????char?buffer[255]?*s;
????
????va_start（args?format）;
????vsprintf（buffer?format?args）;
????va_end（args）;
????
????glRasterPos2i（x?y）;
????for?（s?=?buffer;?*s;?s++）
????????glutBitmapCharacter（font_style?*s）;
}

void
cell_draw（cell*?cell）
{
????glColor3ub（0?255?128）;
????if?（selection?==?cell->id）?{
????????glColor3ub（255?255?0）;
????????drawstr（10?240?cell->info）;
????????glColor3ub（255?0?0）;
????}
????
????drawstr（cell->x?cell->y?cell->format?cell->value）;
}

int
cell_hit（cell*?cell?int?x?int?y）
{
????if?（x?>?cell->x?&&?x?x?+?60?&&
????????y?>?cell->y-30?&&?y?y+10）
????????return?cell->id;
????return?0;
}

void
cell_update（cell*?cell?int?update）
{
????if?（selection?!=?cell->id）
????????return;
????
????cell->value?+=?update?*?cell->step;
????
????if?（cell->value?min）
????????cell->value?=?cell->min;
????else?if?（cel

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2005-11-07?04:19??tutors\data\
?????目錄???????????0??2005-11-07?04:19??tutors\tutors.vc6\
?????目錄???????????0??2005-11-07?04:27??tutors\tutors.vsnetproj\
?????目錄???????????0??2005-11-07?04:19??tutors\tutors.xcodeproj\
?????文件???????12754??2005-11-07?04:19??tutors\fog.c
?????文件???????73728??2005-11-07?04:27??tutors\fog.exe
?????文件???????66463??2005-11-07?04:19??tutors\glm.c
?????文件???????10176??2005-11-07?04:19??tutors\glm.h
?????文件??????237568??2001-11-08?09:27??tutors\glut32.dll
?????文件???????42283??2005-11-07?04:19??tutors\lightmaterial.c
?????文件???????98304??2005-11-07?04:27??tutors\lightmaterial.exe
?????文件???????20769??2005-11-07?04:19??tutors\lightposition.c
?????文件???????77824??2005-11-07?04:27??tutors\lightposition.exe
?????文件????????1542??2005-11-07?04:19??tutors\Makefile
?????文件????????3256??2005-11-07?04:19??tutors\materials.h
?????文件???????24516??2005-11-07?04:19??tutors\projection.c
?????文件???????77824??2005-11-07?04:27??tutors\projection.exe
?????文件???????56171??2005-11-07?04:19??tutors\shapes.c
?????文件???????73728??2005-11-07?04:27??tutors\shapes.exe
?????文件???????35888??2005-11-07?04:19??tutors\texture.c
?????文件???????81920??2005-11-07?04:27??tutors\texture.exe
?????文件???????19117??2005-11-07?04:19??tutors\transformation.c
?????文件???????77824??2005-11-07?04:27??tutors\transformation.exe
?????文件????????1747??2005-11-07?04:19??tutors\data\al.mtl
?????文件??????186752??2005-11-07?04:19??tutors\data\al.obj
?????文件???????49181??2005-11-07?04:19??tutors\data\checker.ppm
?????文件?????????342??2005-11-07?04:19??tutors\data\dolphins.mtl
?????文件???????50315??2005-11-07?04:19??tutors\data\dolphins.obj
?????文件?????????536??2005-11-07?04:19??tutors\data\f-16.mtl
?????文件??????284767??2005-11-07?04:19??tutors\data\f-16.obj
?????文件???????49183??2005-11-07?04:19??tutors\data\fishermen.ppm
............此處省略30個文件信息