我可以找到关于将纹理映射到指定顶点等的多边形的教程，但没有关于如何将纹理应用于使用glut（glutSolidCube）绘制的立方体（或其他东西）的内容。
我正在做类似的事情：
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);
这样做我将纹理应用于立方体，但整个立方体获得纹理中第一个字节的颜色！
使用glutSolidCube时，有没有办法将纹理映射到实体立方体（和其他实体）？
答案 0 :(得分：16)
不，因为glutSolidCube()不会生成纹理坐标。幸运的是，glutSolidCube()很容易实现，并添加纹理坐标。以下是来自 http://www.opengl.org/resources/libraries/glut/的glutSolidCube()及相关函数的源代码：
/* 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);
}
只需添加对glTexCoord*系列函数的一些调用。 NeHe有一个关于如何开始使用OpenGL进行纹理映射的好教程。
答案 1 :(得分：14)
实际上有一种解决方案......
你可以像这样使用生成纹理坐标
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);
答案 2 :(得分：4)
[glutSolidCube生成]适合照明的法线，但不生成纹理坐标（茶壶除外）。
答案 3 :(得分：0)
如果每个现代设计都希望避免使用glBegin\End和GL_TEXTURE_GEN_S\T
void drawBox() {
static glm::vec3 n[6] =
{
{-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 int 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}
};
glm::vec3 v[8];
int i;
v[0][0] = v[1][0] = v[2][0] = v[3][0] = -1;
v[4][0] = v[5][0] = v[6][0] = v[7][0] = 1;
v[0][1] = v[1][1] = v[4][1] = v[5][1] = -1;
v[2][1] = v[3][1] = v[6][1] = v[7][1] = 1;
v[0][2] = v[3][2] = v[4][2] = v[7][2] = -1;
v[1][2] = v[2][2] = v[5][2] = v[6][2] = 1;
auto& surface = surfaces[0];
for ( i = 0; i < 6; i++ ) {
for ( int j = 0; j < 4; j++ )
surface.normals.push_back( n[i] );
auto i1 = i * 4;
surface.indices.push_back( i1 + 0 );
surface.indices.push_back( i1 + 1 );
surface.indices.push_back( i1 + 3 );
surface.indices.push_back( i1 + 1 );
surface.indices.push_back( i1 + 2 );
surface.indices.push_back( i1 + 3 );
surface.vertices.push_back( v[faces[i][0]] );
surface.vertices.push_back( v[faces[i][1]] );
surface.vertices.push_back( v[faces[i][2]] );
surface.vertices.push_back( v[faces[i][3]] );
surface.texCoords.push_back( { 0, 0 } );
surface.texCoords.push_back( { 0, 1 } );
surface.texCoords.push_back( { 1, 0 } );
surface.texCoords.push_back( { 1, 1 } );
}
}