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glutSolidCubeにテクスチャを適用する方法

頂点などを指定するポリゴンへのテクスチャのマッピングに関するチュートリアルはありますが、glut(glutSolidCube)で描画された立方体(またはその他のもの)にテクスチャを適用する方法については何もありません。

私は次のようなことをしています:

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);

これを行うと、テクスチャをキューブに適用できますが、キューブ全体がテクスチャの最初のバイトの色になります。

GlutSolidCubeを使用するときに、テクスチャをソリッドキューブ(および他のソリッド)にマッピングする方法はありますか?

16
JohnIdol

いいえ、glutSolidCube()はテクスチャ座標を生成しないためです。ただし、幸いなことに、glutSolidCube()は簡単に実装でき、テクスチャ座標を追加できます。 http://www.opengl.org/resources/libraries/glut/ からのglutSolidCube()および関連する関数のソースコードは次のとおりです。

/* 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);
}

glTexCoord * 関数ファミリーにいくつかの呼び出しを追加するだけです。 NeHe は、OpenGLを使用したテクスチャマッピングの開始方法に関する優れたチュートリアルがあります。

16
Adam Rosenfield

実際には1つの解決策があります...

このようなテクスチャ座標の生成を使用できます

    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);
15
Humayun

GLUT APIドキュメント によると:

[glutSolidCubeは]照明に適した法線を生成しますが、テクスチャ座標は生成しません(ティーポットを除く)。

4
strager