glGenTextures — generate texture names
C Specification
void glGenTextures(GLsizei n, GLuint * textures);
Parameters
n - Specifies the number of texture names to be generated.
textures - Specifies an array in which the generated texture names are stored.
Description
glGenTextures returns n texture names in textures.
There is no guarantee that the names form a contiguous set of integers;
however, it is guaranteed that none of the returned names was in use
immediately before the call to glGenTextures.
The generated textures have no dimensionality; they assume the dimensionality
of the texture target to which they are first bound
(see glBindTexture).
Texture names returned by a call to glGenTextures are not returned by
subsequent calls, unless they are first deleted with
glDeleteTextures.
Notes
glGenTextures is available only if the GL version is 1.1 or greater.
Errors
GL_INVALID_VALUE is generated if n is negative.
GL_INVALID_OPERATION is generated if glGenTextures is executed
between the execution of glBegin and the corresponding
execution of glEnd.
Associated Gets
glIsTexture
See Also
glBindTexture,
glCopyTexImage1D,
glCopyTexImage2D,
glDeleteTextures,
glGet,
glGetTexParameter,
glTexImage1D,
glTexImage2D,
glTexImage3D,
glTexParameter
Copyright
Copyright © 1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
http://oss.sgi.com/projects/FreeB/.
Examples of glGenTextures
public class Text3d {private IntBuffer mVertexBuffer;
private IntBuffer mColorBuffer;
private ByteBuffer mIndexBuffer;
private FloatBuffer mfTexBuffer;
private int mTextureID;
public Text3d(){
int one = 50;
int vertices[] = {
0, one, 0,
one, one, 0,
0, 0, 0,
one, 0, 0,
};
float tex[] = {
0.0f ,0.0f,
1.0f,0.0f,
0.0f ,1.0f,
1.0f,1.0f,
};
one = 100000;
int colors[] = {
one, one, one, one,
one, one, one, one,
one, one, one, one,
one, one, one, one,
};
byte indices[] = {
0, 1, 2,
1, 3, 2,
};
ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length*4);
vbb.order(ByteOrder.nativeOrder());
mVertexBuffer = vbb.asIntBuffer();
mVertexBuffer.put(vertices);
mVertexBuffer.position(0);
ByteBuffer tbb = ByteBuffer.allocateDirect(tex.length*4);
tbb.order(ByteOrder.nativeOrder());
mfTexBuffer = tbb.asFloatBuffer();
mfTexBuffer.put(tex);
mfTexBuffer.position(0);
ByteBuffer cbb = ByteBuffer.allocateDirect(colors.length*4);
cbb.order(ByteOrder.nativeOrder());
mColorBuffer = cbb.asIntBuffer();
mColorBuffer.put(colors);
mColorBuffer.position(0);
mIndexBuffer = ByteBuffer.allocateDirect(indices.length);
mIndexBuffer.put(indices);
mIndexBuffer.position(0);
}
public void TexCreate(GL10 gl,Context mContext)
{
int[] textures = new int[1];
gl.glGenTextures(1, textures, 0);
mTextureID = textures[0];
gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureID);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
GL10.GL_NEAREST);
gl.glTexParameterf(GL10.GL_TEXTURE_2D,
GL10.GL_TEXTURE_MAG_FILTER,
GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S,
GL10.GL_CLAMP_TO_EDGE);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T,
GL10.GL_CLAMP_TO_EDGE);
gl.glTexEnvf(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE,
GL10.GL_REPLACE);
Bitmap mBitmap;
Canvas mCanvas;
Bitmap.Config config = Bitmap.Config.ARGB_8888;
mBitmap = Bitmap.createBitmap(128, 128, config);
mCanvas = new Canvas(mBitmap);
mBitmap.eraseColor(0);
mCanvas.drawColor(0x00ffffff);
Paint Pnt = new Paint();
Pnt.setColor(0xff00ff00);
Pnt.setTextSize(128);
Pnt.setAntiAlias(false);
Pnt.setTextScaleX(1);
mCanvas.drawText("B", 0, 128, Pnt);
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, mBitmap, 0);
mBitmap.recycle();
}
public void draw(GL10 gl)
{
gl.glFrontFace(GL10.GL_CW);
gl.glEnable(GL10.GL_TEXTURE_2D);
gl.glColor4f(1f, 1f, 1f, 1f);
gl.glTexEnvx(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE,
GL10.GL_MODULATE);
gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureID);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
gl.glActiveTexture(GL10.GL_TEXTURE0);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, mfTexBuffer);
gl.glVertexPointer(3, GL10.GL_FIXED, 0, mVertexBuffer);
gl.glColorPointer(4, GL10.GL_FIXED, 0, mColorBuffer);
gl.glDrawElements(GL10.GL_TRIANGLES, 6, GL10.GL_UNSIGNED_BYTE, mIndexBuffer);
}
}
