我在下面的代码中定义了一个多维数据集。我想为6个面中的每一个指定颜色，如：
正面：color1
背面：color2
左脸：color3
右脸：color4
top face：color5
底面：color6
请注意，在OpenGL ES中，我们只有三角形而不是四边形。我正在寻找能够解决我问题的工作示例代码，因为工作示例代码的价值超过千言万语，就像他们对图片的说法一样。
这是立方体：
float vertices[] = { -width, -height, -depth, // 0
width, -height, -depth, // 1
width, height, -depth, // 2
-width, height, -depth, // 3
-width, -height, depth, // 4
width, -height, depth, // 5
width, height, depth, // 6
-width, height, depth // 7
};
short indices[] = { 0, 2, 1,
0, 3, 2,
1,2,6,
6,5,1,
4,5,6,
6,7,4,
2,3,6,
6,3,7,
0,7,3,
0,4,7,
0,1,5,
0,5,4
};
这是绘图代码：
gl.glFrontFace(GL10.GL_CCW);
// Enable face culling.
gl.glEnable(GL10.GL_CULL_FACE);
// What faces to remove with the face culling.
gl.glCullFace(GL10.GL_BACK);
// Enabled the vertices buffer for writing and to be used during
// rendering.
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
// Specifies the location and data format of an array of vertex
// coordinates to use when rendering.
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mVerticesBuffer);
// Bind the texture according to the set texture filter
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[filter]);
gl.glEnable(GL10.GL_TEXTURE_2D);
if (mColorBuffer != null) {
// Enable the color array buffer to be used during rendering.
gl.glEnableClientState(GL10.GL_COLOR_ARRAY);
gl.glColorPointer(4, GL10.GL_FLOAT, 0, mColorBuffer);
}
gl.glDrawElements(GL10.GL_TRIANGLES, mNumOfIndices,
GL10.GL_UNSIGNED_SHORT, mIndicesBuffer);
// ALL the DRAWING IS DONE NOW
// Disable the vertices buffer.
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
// Disable face culling.
gl.glDisable(GL10.GL_CULL_FACE);
答案 0 :(得分：3)
这是桌面GLUT代码，但核心逻辑应直接转换为OpenGL ES：
#include <GL/glut.h>
#include <cstdlib>
void glutTexturedCube(GLdouble size)
{
GLfloat color1[] = { 255, 0, 0 };
GLfloat color2[] = { 0, 255, 0 };
GLfloat color3[] = { 0, 0, 255 };
GLfloat color4[] = { 255, 255, 0 };
GLfloat color5[] = { 0, 255, 255 };
GLfloat color6[] = { 255, 255, 255 };
GLfloat color[] = {
color1[0], color1[1], color1[2],
color1[0], color1[1], color1[2],
color1[0], color1[1], color1[2],
color1[0], color1[1], color1[2],
color1[0], color1[1], color1[2],
color1[0], color1[1], color1[2],
color2[0], color2[1], color2[2],
color2[0], color2[1], color2[2],
color2[0], color2[1], color2[2],
color2[0], color2[1], color2[2],
color2[0], color2[1], color2[2],
color2[0], color2[1], color2[2],
color3[0], color3[1], color3[2],
color3[0], color3[1], color3[2],
color3[0], color3[1], color3[2],
color3[0], color3[1], color3[2],
color3[0], color3[1], color3[2],
color3[0], color3[1], color3[2],
color4[0], color4[1], color4[2],
color4[0], color4[1], color4[2],
color4[0], color4[1], color4[2],
color4[0], color4[1], color4[2],
color4[0], color4[1], color4[2],
color4[0], color4[1], color4[2],
color5[0], color5[1], color5[2],
color5[0], color5[1], color5[2],
color5[0], color5[1], color5[2],
color5[0], color5[1], color5[2],
color5[0], color5[1], color5[2],
color5[0], color5[1], color5[2],
color6[0], color6[1], color6[2],
color6[0], color6[1], color6[2],
color6[0], color6[1], color6[2],
color6[0], color6[1], color6[2],
color6[0], color6[1], color6[2],
color6[0], color6[1], color6[2],
};
GLfloat vert[] = {
// top (+z)
-1, -1, 1,
1, -1, 1,
-1, 1, 1,
-1, 1, 1,
1, -1, 1,
1, 1, 1,
// bottom (-z)
-1, -1, -1,
-1, 1, -1,
1, -1, -1,
1, -1, -1,
-1, 1, -1,
1, 1, -1,
// right (+x)
1, -1, -1,
1, 1, -1,
1, -1, 1,
1, -1, 1,
1, 1, -1,
1, 1, 1,
// left (-x)
-1, -1, -1,
-1, -1, 1,
-1, 1, -1,
-1, 1, -1,
-1, -1, 1,
-1, 1, 1,
// front (+y)
-1, -1, -1,
1, -1, -1,
-1, -1, 1,
-1, -1, 1,
1, -1, -1,
1, -1, 1,
// back (-y)
-1, 1, -1,
-1, 1, 1,
1, 1, -1,
1, 1, -1,
-1, 1, 1,
1, 1, 1,
};
GLushort idxs[] = {
0, 1, 2,
3, 4, 5,
6, 7, 8,
9,10,11,
12,13,14,
15,16,17,
18,19,20,
21,22,23,
24,25,26,
27,28,29,
30,31,32,
33,34,35
};
glEnableClientState(GL_COLOR_ARRAY);
glEnableClientState(GL_VERTEX_ARRAY);
glColorPointer(3, GL_FLOAT, 0, color);
glVertexPointer(3, GL_FLOAT, 0, vert);
glPushMatrix();
glColor4f(1, 1, 1, 1);
glScaled(size, size, size);
glDrawElements(GL_TRIANGLES, sizeof(idxs)/sizeof(idxs[0]), GL_UNSIGNED_SHORT, idxs);
glPopMatrix();
glDisableClientState(GL_COLOR_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);
}
static GLuint texName;
void init(void)
{
glClearColor(0,0,0,0);
glEnable(GL_DEPTH_TEST);
glShadeModel(GL_SMOOTH);
glEnable(GL_CULL_FACE);
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// projection
glMatrixMode(GL_PROJECTION); glLoadIdentity();
int viewport[4]; glGetIntegerv(GL_VIEWPORT, viewport);
gluPerspective(60.0, (GLdouble)viewport[2]/(GLdouble)viewport[3], 1.0, 100.0 );
// view transform
glMatrixMode(GL_MODELVIEW); glLoadIdentity();
glTranslatef(0,0,-4);
// render
glPushMatrix();
const float ANGLE_SPEED = 30; // degrees/sec
float angle = ANGLE_SPEED * (glutGet(GLUT_ELAPSED_TIME) / 1000.0f);
glRotatef(angle*0.5f, 1, 0, 0);
glRotatef(angle, 0, 1, 0);
glRotatef(angle*0.7f, 0, 0, 1);
glutTexturedCube(1);
glutSwapBuffers();
}
void reshape(int w, int h)
{
glViewport(0, 0, (GLsizei) w, (GLsizei) h);
}
void keyboard (unsigned char key, int x, int y)
{
switch (key)
{
case 27: exit(0); break;
default: break;
}
}
void idle()
{
glutPostRedisplay();
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH);
glutInitWindowSize(640, 480);
glutInitWindowPosition(100, 100);
glutCreateWindow (argv[0]);
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutKeyboardFunc(keyboard);
glutIdleFunc(idle);
init();
glutMainLoop();
return 0;
}