opengl - texture - Cómo aplicar textura a glutSolidCube

texture in opengl c++

Question

Puedo encontrar tutoriales sobre el mapeo de texturas a polígonos especificando vértices, etc., pero nada sobre cómo aplicar una textura a un cubo (u otro material) dibujado con exceso (glutSolidCube).

Estoy haciendo algo como:

glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, decal);
glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, repeat);
glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, repeat);
glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, nearest);
glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, nearest);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glTexImage2D(GL_TEXTURE_2D, 0, 4, myImageWidth, myImageHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid *)myImage);
//...
glEnable(GL_TEXTURE_2D);
//now draw the cube
glutSolidCube(N);

Al hacer esto obtengo la textura para aplicar al cubo, ¡pero todo el cubo obtiene el color del primer byte en la textura!

¿Hay alguna manera de mapear una textura en un cubo sólido (y otros sólidos) cuando se utiliza glutSolidCube?

Answer 1

De acuerdo con la documentación de API GLUT :

[glutSolidCube genera] normales apropiadas para iluminación pero no generan coordenadas de textura (excepto para la tetera).

Answer 2

No, ya que glutSolidCube() no genera coordenadas de textura. Afortunadamente, sin embargo, glutSolidCube() es fácil de implementar y agrega coordenadas de textura. Aquí está el código fuente de glutSolidCube() y las funciones asociadas, de http://www.opengl.org/resources/libraries/glut/ :

/* Copyright (c) Mark J. Kilgard, 1994, 1997. */
/**
(c) Copyright 1993, Silicon Graphics, Inc.
ALL RIGHTS RESERVED
Permission to use, copy, modify, and distribute this software
for any purpose and without fee is hereby granted, provided
that the above copyright notice appear in all copies and that
both the copyright notice and this permission notice appear in
supporting documentation, and that the name of Silicon
Graphics, Inc. not be used in advertising or publicity
pertaining to distribution of the software without specific,
written prior permission.
THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU
"AS-IS" AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR
OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO
EVENT SHALL SILICON GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE
ELSE FOR ANY DIRECT, SPECIAL, INCIDENTAL, INDIRECT OR
CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER,
INCLUDING WITHOUT LIMITATION, LOSS OF PROFIT, LOSS OF USE,
SAVINGS OR REVENUE, OR THE CLAIMS OF THIRD PARTIES, WHETHER OR
NOT SILICON GRAPHICS, INC. HAS BEEN ADVISED OF THE POSSIBILITY
OF SUCH LOSS, HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
ARISING OUT OF OR IN CONNECTION WITH THE POSSESSION, USE OR
PERFORMANCE OF THIS SOFTWARE.
US Government Users Restricted Rights
Use, duplication, or disclosure by the Government is subject to
restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
(c)(1)(ii) of the Rights in Technical Data and Computer
Software clause at DFARS 252.227-7013 and/or in similar or
successor clauses in the FAR or the DOD or NASA FAR
Supplement. Unpublished-- rights reserved under the copyright
laws of the United States. Contractor/manufacturer is Silicon
Graphics, Inc., 2011 N. Shoreline Blvd., Mountain View, CA
94039-7311.
OpenGL(TM) is a trademark of Silicon Graphics, Inc.
*/
static void
drawBox(GLfloat size, GLenum type)
{
static GLfloat n[6][3] =
{
{-1.0, 0.0, 0.0},
{0.0, 1.0, 0.0},
{1.0, 0.0, 0.0},
{0.0, -1.0, 0.0},
{0.0, 0.0, 1.0},
{0.0, 0.0, -1.0}
};
static GLint faces[6][4] =
{
{0, 1, 2, 3},
{3, 2, 6, 7},
{7, 6, 5, 4},
{4, 5, 1, 0},
{5, 6, 2, 1},
{7, 4, 0, 3}
};
GLfloat v[8][3];
GLint i;
v[0][0] = v[1][0] = v[2][0] = v[3][0] = -size / 2;
v[4][0] = v[5][0] = v[6][0] = v[7][0] = size / 2;
v[0][1] = v[1][1] = v[4][1] = v[5][1] = -size / 2;
v[2][1] = v[3][1] = v[6][1] = v[7][1] = size / 2;
v[0][2] = v[3][2] = v[4][2] = v[7][2] = -size / 2;
v[1][2] = v[2][2] = v[5][2] = v[6][2] = size / 2;
for (i = 5; i >= 0; i--) {
glBegin(type);
glNormal3fv(&n[i][0]);
glVertex3fv(&v[faces[i][0]][0]);
glVertex3fv(&v[faces[i][1]][0]);
glVertex3fv(&v[faces[i][2]][0]);
glVertex3fv(&v[faces[i][3]][0]);
glEnd();
}
}
void APIENTRY
glutSolidCube(GLdouble size)
{
drawBox(size, GL_QUADS);
}

Solo agregue algunas llamadas a la familia de funciones glTexCoord * . NeHe tiene un buen tutorial sobre cómo comenzar a mapear texturas con OpenGL.

Answer 3

En realidad, hay una solución ...

puedes usar generar coordenadas de textura como esta

 glEnable(GL_TEXTURE_GEN_S); //enable texture coordinate generation
glEnable(GL_TEXTURE_GEN_T);
glBindTexture(GL_TEXTURE_2D, theTexture[2]);
glutSolidCube(2);
glDisable(GL_TEXTURE_GEN_S); //enable texture coordinate generation
glDisable(GL_TEXTURE_GEN_T);