diff options
Diffstat (limited to 'progs/demos')
| -rw-r--r-- | progs/demos/lodbias.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/progs/demos/lodbias.c b/progs/demos/lodbias.c new file mode 100644 index 00000000000..e36acc67cdf --- /dev/null +++ b/progs/demos/lodbias.c @@ -0,0 +1,217 @@ +/* + * GL_EXT_texture_lod_bias demo + * + * Thanks to Michael Vance for implementing this extension in Mesa. + * + * Brian Paul + * 20 March 2000 + * + * Copyright (C) 2000 Brian Paul All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN + * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + + +#include <stdlib.h> +#include <stdio.h> +#include <math.h> +#include <GL/glut.h> +#include <GL/glext.h> + +#include "../util/readtex.c" /* I know, this is a hack. */ + +#define TEXTURE_FILE "../images/girl.rgb" + +static GLfloat Xrot = 0, Yrot = -30, Zrot = 0; +static GLboolean Anim = GL_TRUE; +static GLint Bias = 0, DeltaBias = 10; /* ints avoid fp precision problem */ +static GLint BiasMin = -200, BiasMax = 300; + + + +static void +PrintString(const char *s) +{ + while (*s) { + glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s); + s++; + } +} + +static void Idle( void ) +{ + Bias += DeltaBias; + if (Bias < BiasMin) { + Bias = BiasMin; + DeltaBias = 10; + } + else if (Bias > BiasMax) { + Bias = BiasMax; + DeltaBias = -10; + } + + glutPostRedisplay(); +} + + +static void Display( void ) +{ + char str[100]; + + glClear( GL_COLOR_BUFFER_BIT ); + + glMatrixMode( GL_PROJECTION ); + glLoadIdentity(); + glOrtho(-1, 1, -1, 1, -1, 1); + glMatrixMode( GL_MODELVIEW ); + glLoadIdentity(); + + glDisable(GL_TEXTURE_2D); + glColor3f(1,1,1); + glRasterPos3f(-0.9, -0.9, 0.0); + sprintf(str, "Texture LOD Bias = %4.1f", Bias * 0.01); + PrintString(str); + + glMatrixMode( GL_PROJECTION ); + glLoadIdentity(); + glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 25.0 ); + glMatrixMode( GL_MODELVIEW ); + glLoadIdentity(); + glTranslatef( 0.0, 0.0, -8.0 ); + + glPushMatrix(); + glRotatef(Xrot, 1, 0, 0); + glRotatef(Yrot, 0, 1, 0); + glRotatef(Zrot, 0, 0, 1); + + glEnable(GL_TEXTURE_2D); + glTexEnvf(GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, 0.01 * Bias); + + glBegin(GL_POLYGON); + glTexCoord2f(0, 0); glVertex2f(-1, -1); + glTexCoord2f(2, 0); glVertex2f( 1, -1); + glTexCoord2f(2, 2); glVertex2f( 1, 1); + glTexCoord2f(0, 2); glVertex2f(-1, 1); + glEnd(); + + glPopMatrix(); + + glutSwapBuffers(); +} + + +static void Reshape( int width, int height ) +{ + glViewport( 0, 0, width, height ); +} + + +static void Key( unsigned char key, int x, int y ) +{ + const GLfloat step = 3.0; + (void) x; + (void) y; + switch (key) { + case 'a': + Anim = !Anim; + if (Anim) + glutIdleFunc(Idle); + else + glutIdleFunc(NULL); + break; + case 'z': + Zrot -= step; + break; + case 'Z': + Zrot += step; + break; + case 'b': + Bias -= 10; + break; + case 'B': + Bias += 10; + break; + case 27: + exit(0); + break; + } + glutPostRedisplay(); +} + + +static void SpecialKey( int key, int x, int y ) +{ + const GLfloat step = 3.0; + (void) x; + (void) y; + switch (key) { + case GLUT_KEY_UP: + Xrot -= step; + break; + case GLUT_KEY_DOWN: + Xrot += step; + break; + case GLUT_KEY_LEFT: + Yrot -= step; + break; + case GLUT_KEY_RIGHT: + Yrot += step; + break; + } + glutPostRedisplay(); +} + + +static void Init( void ) +{ + const char *exten = (const char *) glGetString(GL_EXTENSIONS); + if (!strstr(exten, "GL_EXT_texture_lod_bias")) { + printf("Sorry, GL_EXT_texture_lod_bias not supported by this renderer.\n"); + exit(1); + } + + glPixelStorei(GL_UNPACK_ALIGNMENT, 1); + if (!LoadRGBMipmaps(TEXTURE_FILE, GL_RGB)) { + printf("Error: could not load texture image %s\n", TEXTURE_FILE); + exit(1); + } + + /* mipmapping required for this extension */ + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); + glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); +} + + +int main( int argc, char *argv[] ) +{ + glutInit( &argc, argv ); + glutInitWindowPosition( 0, 0 ); + glutInitWindowSize( 350, 350 ); + glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE ); + glutCreateWindow(argv[0]); + glutReshapeFunc( Reshape ); + glutKeyboardFunc( Key ); + glutSpecialFunc( SpecialKey ); + glutDisplayFunc( Display ); + if (Anim) + glutIdleFunc(Idle); + Init(); + glutMainLoop(); + return 0; +} |