/t_backcompat/OpenGL/tutorial/lesson08.pl
Perl | 367 lines | 250 code | 82 blank | 35 comment | 28 complexity | f945af147d8f1641e385d18d8955506e MD5 | raw file
1#!/usr/bin/perl -w 2# This code was created by Jeff Molofee '99 3# (ported to SDL by Sam Lantinga '2000) 4# (ported to Perl/SDL by Wayne Keenan '2000) 5# 6# If you've found this code useful, please let me know. 7# 8# Visit me at www.demonews.com/hosted/nehe 9 10use strict; 11use Getopt::Long; 12use Data::Dumper; 13use Benchmark; 14 15use SDL; 16use SDLx::App; 17use SDL::OpenGL; 18use SDL::Event; 19use SDL::Surface; 20use SDL::Cursor; 21use SDL::OpenGL; 22 23my $arg_screen_width = 640; 24my $arg_screen_height = 512; 25my $arg_fullscreen = 0; 26 27GetOptions( 28 "width:i" => \$arg_screen_width, 29 "height:i" => \$arg_screen_height, 30 "fullscreen!" => \$arg_fullscreen, 31 32) or die $!; 33 34############################################################ 35 36my $light = 0; 37 38my $xrot = 0; # x rotation 39my $yrot = 0; # y rotation 40my $xspeed = 0; # x rotation speed 41my $yspeed = 0; # y rotation speed 42 43my $z = -5.0; # depth into the screen. 44 45my $filter = 1; # Which Filter To Use (nearest/linear/mipmapped) */ 46my $blend = 1; 47 48print STDERR "Use b to toggle blend, page up/down to zoom, and arrow keys to rotate\n"; 49 50main(); 51exit; 52 53sub main { 54 my $done = 0; 55 my $vidmode_flags = SDL_OPENGL; 56 57 $vidmode_flags |= SDL_FULLSCREEN if $arg_fullscreen; 58 59 my $app = SDLx::App->new( 60 -title => "Jeff Molofee's GL Code Tutorial ... NeHe '99", 61 -icon => "icon.png", 62 -flags => $vidmode_flags, 63 -width => $arg_screen_width, 64 -height => $arg_screen_height, 65 -opengl => 1, 66 ); 67 68 SDL::ShowCursor(0); 69 70 my $event = SDL::Event->new; 71 $event->set( SDL_SYSWMEVENT, SDL_IGNORE ); 72 73 InitGL( $arg_screen_width, $arg_screen_height ); 74 75 glEnable(GL_BLEND); # Turn Blending On 76 glEnable(GL_LIGHTING); 77 glDisable(GL_DEPTH_TEST); # Turn Depth Testing Off 78 79 while ( not $done ) { 80 81 DrawGLScene(); 82 83 $app->sync(); 84 85 $event->pump; 86 $event->poll; 87 88 $done = 1 if ( $event->type == SDL_QUIT ); 89 90 if ( $event->type == SDL_KEYDOWN ) { 91 my $key = $event->key_sym; 92 93 $done = 1 if ( $key == SDLK_ESCAPE ); 94 95 if ( $key == SDLK_f ) { 96 printf( "Filter was: %d\n", $filter ); 97 $filter = 1 + ( ($filter) % 3 ); 98 printf( "Filter is now: %d\n", $filter ); 99 $app->delay(100); 100 } 101 if ( $key == SDLK_b ) { 102 printf( "Blend was: %d\n", $blend ); 103 $blend = $blend ? 0 : 1; 104 printf( "Blend is now: %d\n", $blend ); 105 $app->delay(100); 106 if ($blend) { 107 glEnable(GL_BLEND); # Turn Blending On 108 glEnable(GL_LIGHTING); 109 glDisable(GL_DEPTH_TEST); # Turn Depth Testing Off 110 } else { 111 glDisable(GL_BLEND); # Turn Blending Off 112 glDisable(GL_LIGHTING); 113 glEnable(GL_DEPTH_TEST); # Turn Depth Testing On 114 } 115 } 116 117 #bit lax: 118 $z -= 0.02 if ( $key == SDLK_PAGEUP ); 119 $z += 0.02 if ( $key == SDLK_PAGEDOWN ); 120 $xspeed += 0.02 if ( $key == SDLK_UP ); 121 $xspeed -= 0.02 if ( $key == SDLK_DOWN ); 122 $yspeed -= 0.01 if ( $key == SDLK_LEFT ); 123 $yspeed += 0.01 if ( $key == SDLK_RIGHT ); 124 125 } 126 } 127} 128 129######################################################################### 130#Pretty much in original form, but 'Perlised' 131 132sub InitGL { 133 my ( $Width, $Height ) = @_; 134 135 glViewport( 0, 0, $Width, $Height ); 136 137 LoadGLTextures(); # Load The Texture(s) 138 139 glEnable(GL_TEXTURE_2D); # Enable Texture Mapping 140 141 glClearColor( 0.0, 0.0, 0.0, 0.0 ); # This Will Clear The Background Color To Black 142 glClearDepth(1.0); # Enables Clearing Of The Depth Buffer 143 glDepthFunc(GL_LESS); # The Type Of Depth Test To Do 144 glEnable(GL_DEPTH_TEST); # Enables Depth Testing 145 glShadeModel(GL_SMOOTH); # Enables Smooth Color Shading 146 147 glMatrixMode(GL_PROJECTION); 148 glLoadIdentity(); # Reset The Projection Matrix 149 150 gluPerspective( 45.0, $Width / $Height, 0.1, 100.0 ); # Calculate The Aspect Ratio Of The Window 151 152 glMatrixMode(GL_MODELVIEW); 153 154 my $LightAmbient = [ 0.5, 0.5, 0.5, 1.0 ]; # white ambient light at half intensity (rgba) */ 155 156 my $LightDiffuse = [ 1.0, 1.0, 1.0, 1.0 ]; # super bright, full intensity diffuse light. */ 157 158 my $LightPosition = [ 0.0, 0.0, 2.0, 1.0 ]; # position of light (x, y, z, (position of light)) */ 159 160 #setup light number 1 161 glLight( GL_LIGHT1, GL_AMBIENT, @$LightAmbient ); # add lighting. (ambient) 162 glLight( GL_LIGHT1, GL_DIFFUSE, @$LightDiffuse ); # add lighting. (diffuse). 163 glLight( GL_LIGHT1, GL_POSITION, @$LightPosition ); # set light position. 164 glEnable(GL_LIGHT1); # turn light 1 on. 165 #/* setup blending */ 166 glBlendFunc( GL_SRC_ALPHA, GL_ONE ); # Set The Blending Function For Translucency 167 glColor( 1.0, 1.0, 1.0, 0.5 ); 168 169} 170 171# The main drawing function. 172sub DrawGLScene { 173 glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); # Clear The Screen And The Depth Buffer 174 glLoadIdentity(); # Reset The View 175 176 glTranslate( 0.0, 0.0, $z ); # move z units out from the screen. 177 178 glRotate( $xrot, 1.0, 0.0, 0.0 ); # Rotate On The X Axis 179 glRotate( $yrot, 0.0, 1.0, 0.0 ); # Rotate On The Y Axis 180 181 glBindTexture( GL_TEXTURE_2D, $filter ); # choose the texture to use. 182 183 glBegin(GL_QUADS); # begin drawing a cube 184 185 # Front Face (note that the texture's corners have to match the quad's corners) 186 glNormal( 0.0, 0.0, 1.0 ); # front face points out of the screen on z. 187 glTexCoord( 0.0, 0.0 ); 188 glVertex( -1.0, -1.0, 1.0 ); # Bottom Left Of The Texture and Quad 189 glTexCoord( 1.0, 0.0 ); 190 glVertex( 1.0, -1.0, 1.0 ); # Bottom Right Of The Texture and Quad 191 glTexCoord( 1.0, 1.0 ); 192 glVertex( 1.0, 1.0, 1.0 ); # Top Right Of The Texture and Quad 193 glTexCoord( 0.0, 1.0 ); 194 glVertex( -1.0, 1.0, 1.0 ); # Top Left Of The Texture and Quad 195 196 # Back Face 197 glNormal( 0.0, 0.0, -1.0 ); # back face points into the screen on z. 198 glTexCoord( 1.0, 0.0 ); 199 glVertex( -1.0, -1.0, -1.0 ); # Bottom Right Of The Texture and Quad 200 glTexCoord( 1.0, 1.0 ); 201 glVertex( -1.0, 1.0, -1.0 ); # Top Right Of The Texture and Quad 202 glTexCoord( 0.0, 1.0 ); 203 glVertex( 1.0, 1.0, -1.0 ); # Top Left Of The Texture and Quad 204 glTexCoord( 0.0, 0.0 ); 205 glVertex( 1.0, -1.0, -1.0 ); # Bottom Left Of The Texture and Quad 206 207 # Top Face 208 glNormal( 0.0, 1.0, 0.0 ); # top face points up on y. 209 glTexCoord( 0.0, 1.0 ); 210 glVertex( -1.0, 1.0, -1.0 ); # Top Left Of The Texture and Quad 211 glTexCoord( 0.0, 0.0 ); 212 glVertex( -1.0, 1.0, 1.0 ); # Bottom Left Of The Texture and Quad 213 glTexCoord( 1.0, 0.0 ); 214 glVertex( 1.0, 1.0, 1.0 ); # Bottom Right Of The Texture and Quad 215 glTexCoord( 1.0, 1.0 ); 216 glVertex( 1.0, 1.0, -1.0 ); # Top Right Of The Texture and Quad 217 218 # Bottom Face 219 glNormal( 0.0, -1.0, 0.0 ); # bottom face points down on y. 220 glTexCoord( 1.0, 1.0 ); 221 glVertex( -1.0, -1.0, -1.0 ); # Top Right Of The Texture and Quad 222 glTexCoord( 0.0, 1.0 ); 223 glVertex( 1.0, -1.0, -1.0 ); # Top Left Of The Texture and Quad 224 glTexCoord( 0.0, 0.0 ); 225 glVertex( 1.0, -1.0, 1.0 ); # Bottom Left Of The Texture and Quad 226 glTexCoord( 1.0, 0.0 ); 227 glVertex( -1.0, -1.0, 1.0 ); # Bottom Right Of The Texture and Quad 228 229 # Right face 230 glNormal( 1.0, 0.0, 0.0 ); # right face points right on x. 231 glTexCoord( 1.0, 0.0 ); 232 glVertex( 1.0, -1.0, -1.0 ); # Bottom Right Of The Texture and Quad 233 glTexCoord( 1.0, 1.0 ); 234 glVertex( 1.0, 1.0, -1.0 ); # Top Right Of The Texture and Quad 235 glTexCoord( 0.0, 1.0 ); 236 glVertex( 1.0, 1.0, 1.0 ); # Top Left Of The Texture and Quad 237 glTexCoord( 0.0, 0.0 ); 238 glVertex( 1.0, -1.0, 1.0 ); # Bottom Left Of The Texture and Quad 239 240 # Left Face 241 glNormal( -1.0, 0.0, 0.0 ); # left face points left on x. 242 glTexCoord( 0.0, 0.0 ); 243 glVertex( -1.0, -1.0, -1.0 ); # Bottom Left Of The Texture and Quad 244 glTexCoord( 1.0, 0.0 ); 245 glVertex( -1.0, -1.0, 1.0 ); # Bottom Right Of The Texture and Quad 246 glTexCoord( 1.0, 1.0 ); 247 glVertex( -1.0, 1.0, 1.0 ); # Top Right Of The Texture and Quad 248 glTexCoord( 0.0, 1.0 ); 249 glVertex( -1.0, 1.0, -1.0 ); # Top Left Of The Texture and Quad 250 251 glEnd(); # done with the polygon. 252 253 $xrot += $xspeed; # X Axis Rotation 254 $yrot += $yspeed; # Y Axis Rotation 255 256} 257 258sub LoadGLTextures { 259 260 # Load Texture 261 262 my ( $pixels, $width, $height, $size ) = ImageLoad("Data/glass.bmp"); 263 264 # Create Texture 265 266 glGenTextures(3); 267 268 # texture 1 (poor quality scaling) 269 glBindTexture( GL_TEXTURE_2D, 1 ); # 2d texture (x and y size) 270 271 glTexParameter( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST ); # cheap scaling when image bigger than texture 272 glTexParameter( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST ); # cheap scaling when image smalled than texture 273 274 # 2d texture, level of detail 0 (normal), 3 components (red, green, blue), x size from image, y size from image, 275 # border 0 (normal), rgb color data, unsigned byte data, and finally the data itself. 276 #glTexImage2D(GL_TEXTURE_2D, 0, 3, image1->w, image1->h, 0, GL_RGB, GL_UNSIGNED_BYTE, image1->pixels); 277 278 glTexImage2D( GL_TEXTURE_2D, 279 0, #level (0 normal, heighr is form mip-mapping) 280 3, #internal format (3=GL_RGB) 281 $width, $height, 282 0, # border 283 GL_RGB, #format RGB color data 284 GL_UNSIGNED_BYTE, #unsigned bye data 285 $pixels 286 ); #ptr to texture data 287 288 # texture 2 (linear scaling) 289 glBindTexture( GL_TEXTURE_2D, 2 ); # 2d texture (x and y size) 290 glTexParameter( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR ); # scale linearly when image bigger than texture 291 glTexParameter( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR ); # scale linearly when image smalled than texture 292 #glTexImage2D(GL_TEXTURE_2D, 0, 3, image1->w, image1->h, 0, GL_RGB, GL_UNSIGNED_BYTE, image1->pixels); 293 294 glTexImage2D( GL_TEXTURE_2D, 295 0, #level (0 normal, heighr is form mip-mapping) 296 3, #internal format (3=GL_RGB) 297 $width, $height, 298 0, # border 299 GL_RGB, #format RGB color data 300 GL_UNSIGNED_BYTE, #unsigned bye data 301 $pixels 302 ); #ptr to texture data 303 304 # texture 3 (mipmapped scaling) 305 glBindTexture( GL_TEXTURE_2D, 3 ); # 2d texture (x and y size) 306 glTexParameter( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR ); # scale linearly when image bigger than texture 307 glTexParameter( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, 308 GL_LINEAR_MIPMAP_NEAREST 309 ); # scale linearly + mipmap when image smalled than texture 310 #glTexImage2D(GL_TEXTURE_2D, 0, 3, image1->w, image1->h, 0, GL_RGB, GL_UNSIGNED_BYTE, image1->pixels); 311 312 glTexImage2D( GL_TEXTURE_2D, 313 0, #level (0 normal, heighr is form mip-mapping) 314 3, #internal format (3=GL_RGB) 315 $width, $height, 316 0, # border 317 GL_RGB, #format RGB color data 318 GL_UNSIGNED_BYTE, #unsigned bye data 319 $pixels 320 ); #ptr to texture data 321 322 # 2d texture, 3 colors, width, height, RGB in that order, byte data, and the data. 323 gluBuild2DMipmaps( GL_TEXTURE_2D, 3, $width, $height, GL_RGB, 324 GL_UNSIGNED_BYTE, $pixels 325 ); 326 327 my $glerr = glGetError(); 328 die "Problem setting up 2d Texture (dimensions not a power of 2?)):" . gluErrorString($glerr) . "\n" 329 if $glerr; 330 331} 332 333#somthing needs to keep the ref count alive for objects which represents data in C space (they have no ref count): 334my @ref = (); 335 336sub ImageLoad { 337 my $filename = shift; 338 339 my $surface = SDL::Surface->new( -name => $filename ); #makes use of SDL: BMP loader. 340 341 my $width = $surface->width(); 342 my $height = $surface->height(); 343 my $bytespp = $surface->bytes_per_pixel(); 344 my $size = $width * $height * $bytespp; 345 346 my $surface_pixels = $surface->pixels(); 347 my $surface_size = $width * $height * $surface->bytes_per_pixel(); 348 my $raw_pixels = reverse $surface_pixels; 349 350 #do a conversion (the pixel data is accessable as a simple string) 351 352 my $pixels = $raw_pixels; 353 my $pre_conv = $pixels; 354 my $new_pixels = ""; 355 for ( my $y = 0; $y < $height; $y++ ) { 356 my $y_pos = $y * $width * $bytespp; #calculate offset into the image (a string) 357 my $row = substr( $pre_conv, $y_pos, $width * $bytespp ); #extract 1 pixel row 358 $row =~ s/\G(.)(.)(.)/$3$2$1/gms; #turn the BMP BGR order into OpenGL RGB order; 359 $new_pixels .= reverse $row; 360 } 361 362 $raw_pixels = $new_pixels; #put transformed data into C array. 363 push @ref, $raw_pixels, $surface; 364 365 #we could have created another SDL surface frm the '$raw_pixel's... oh well. 366 return ( $raw_pixels, $width, $height, $size ); 367}