激活/使用GL_TEXTURE1在OpenGL ES 2.0的Android版 [英] Activating/using GL_TEXTURE1 at OpenGL ES 2.0 for Android
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问题描述
我试图用GL_TEXTURE1纹理单元绘制一个简单的形状。我知道如何使用标准GL_TEXTURE0画它，但是当它改变的东西是行不通的。
我想，从我下面的code，我不得不改变如下：
glActiveTexture（GL_TEXTURE1）;
glUniform1i（uTextureLocation，1）;
什么我失踪？
code：
公共类RendererClass实现渲染器{
上下文语境;
FloatBuffer verticesInBuffer;
INT aPositionLocation;
INT aTextureLocation;
INT uTextureLocation;
INT方案;
公共RendererClass（上下文的背景下）{
this.context =背景;
}
@覆盖
公共无效onSurfaceCreated（GL10为arg0，EGLConfig配置）{
GLES20.glClearColor（1.0F，0.0，0.0，0.0）;
浮动[]顶点= {
-0.5f，0.5F，0.5F，0.5F，
-1.0F，0.0，0.0，0.0，
0.0，0.0，1.0F，0.0，
0.0，1.0F，1.0F，1.0F，
-1.0F，1.0F，0.0，1.0F，
-1.0F，0.0，0.0，0.0
};
verticesInBuffer = ByteBuffer.allocateDirect(vertices.length*4).order(ByteOrder.nativeOrder()).asFloatBuffer().put(vertices);
字符串VSS =属性vec4 a_Position; +
属性VEC2 a_Texture; +
不同VEC2 v_Texture; +
无效的主要（）{+
v_Texture = a_Texture; +
GL_POSITION = a_Position; +
};
字符串FSS =precision mediump浮动; +
不同VEC2 v_Texture; +
统一sampler2D u_Texture; +
无效的主要（）{+
gl_FragColor =的Texture2D（u_Texture，v_Texture）; +
};
INT VS = glCreateShader（GL_VERTEX_SHADER）;
INT FS = glCreateShader（GL_FRAGMENT_SHADER）;
glShaderSource（VS，VSS）;
glShaderSource（FS，FSS）;
glCompileShader（VS）;
glCompileShader（FS）;
程序= glCreateProgram（）;
glAttachShader（程序，VS）;
glAttachShader（程序，FS）;
glLinkProgram（节目）;
aPositionLocation = glGetAttribLocation（节目a_Position）;
// *****质地的东西开始此处＆lt; /＆LT; /＆LT; /＆LT; /
// FASE 1
glActiveTexture（GL_TEXTURE0）;
INT [] genTextures =新INT [1];
glGenTextures（1，genTextures，0）;
glBindTexture（GL_TEXTURE_2D，genTextures [0]）;
glTexParameteri（GL_TEXTURE_2D，GL_TEXTURE_MIN_FILTER，GL_LINEAR_MIPMAP_LINEAR）;
glTexParameteri（GL_TEXTURE_2D，GL_TEXTURE_MAG_FILTER，GL_NEAREST）;
// FASE 2
BitmapFactory.Options选项=新BitmapFactory.Options（）;
options.inScaled = FALSE;
位图bitmap1 = BitmapFactory.de codeResource（context.getResources（），R.drawable.res_for_test_1，期权）;
// FASE 3
texImage2D（GL_TEXTURE_2D，0，bitmap1，0）;
glGenerateMipmap（GL_TEXTURE_2D）;
// FASE 4
aTextureLocation = glGetAttribLocation（节目a_Texture）;
uTextureLocation = glGetUniformLocation（节目u_Texture）;
glUniform1i（uTextureLocation，0）;
verticesInBuffer.position（2）;
glEnableVertexAttribArray（aTextureLocation）;
glVertexAttribPointer（aTextureLocation，2，GL_FLOAT，假的，16，verticesInBuffer）;
// *****质地的东西两端此处＆lt; /＆LT; /＆LT; /＆LT; /
}
@覆盖
公共无效onSurfaceChanged（GL10为arg0，诠释的宽度，高度INT）{
GLES20.glViewport（0，0，宽度，高度）;
}
@覆盖
公共无效onDrawFrame（GL10 glUnused）{
GLES20.glClear（GLES20.GL_COLOR_BUFFER_BIT）;
glUseProgram（节目）;
verticesInBuffer.position（0）;
glEnableVertexAttribArray（aPositionLocation）;
glVertexAttribPointer（aPositionLocation，2，GL_FLOAT，假的，16，verticesInBuffer）;
（4,8，GL_TRIANGLE_FAN，0,6）;
}
}
解决方案
您需要指定活动纹理单元和分配previously载入纹理。
为了方便起见，我创建了一个辅助功能，做了这一切。它激活特定纹理单元，与给定的ID分配纹理，并把着色器的这个值 sampler2D 统一的：
保护无效setTexture2D（INT textureUnit，诠释textureID，诠释uniformID）{
GLES20.glActiveTexture（GLES20.GL_TEXTURE0 + textureUnit）;
GLES20.glBindTexture（GLES20.GL_TEXTURE_2D，textureID）;
GLES20.glUniform1i（uniformID，textureUnit）;
}
然后调用它是这样的：
setTexture2D（0，textureID，uniformID）;
I'm trying to use the GL_TEXTURE1 texture unit to draw a simple shape. I know how to draw it using the standard GL_TEXTURE0, but when changing it something is not working.
I thought that from my code below, I just had to change the following:
glActiveTexture(GL_TEXTURE1);
glUniform1i(uTextureLocation, 1);
What I'm missing?
Code:
public class RendererClass implements Renderer {
Context context;
FloatBuffer verticesInBuffer;
int aPositionLocation;
int aTextureLocation;
int uTextureLocation;
int program;
public RendererClass(Context context){
this.context = context;
}
@Override
public void onSurfaceCreated(GL10 arg0, EGLConfig config) {
GLES20.glClearColor(1.0f, 0.0f, 0.0f, 0.0f);
float[] vertices = {
-0.5f, 0.5f, 0.5f, 0.5f,
-1.0f, 0.0f, 0.0f, 0.0f,
0.0f, 0.0f, 1.0f, 0.0f,
0.0f, 1.0f, 1.0f, 1.0f,
-1.0f, 1.0f, 0.0f, 1.0f,
-1.0f, 0.0f, 0.0f, 0.0f
};
verticesInBuffer = ByteBuffer.allocateDirect(vertices.length*4).order(ByteOrder.nativeOrder()).asFloatBuffer().put(vertices);
String vss = "attribute vec4 a_Position;" +
"attribute vec2 a_Texture;" +
"varying vec2 v_Texture;" +
"void main(){" +
" v_Texture = a_Texture;" +
" gl_Position = a_Position;" +
"}";
String fss = "precision mediump float;" +
"varying vec2 v_Texture;" +
"uniform sampler2D u_Texture;" +
"void main(){" +
" gl_FragColor = texture2D(u_Texture, v_Texture);" +
"}";
int vs = glCreateShader(GL_VERTEX_SHADER);
int fs = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(vs, vss);
glShaderSource(fs, fss);
glCompileShader(vs);
glCompileShader(fs);
program = glCreateProgram();
glAttachShader(program, vs);
glAttachShader(program, fs);
glLinkProgram(program);
aPositionLocation = glGetAttribLocation(program, "a_Position");
// ***** Texture stuff starts here </</</</
// Fase 1
glActiveTexture(GL_TEXTURE0);
int[] genTextures = new int[1];
glGenTextures(1, genTextures, 0);
glBindTexture(GL_TEXTURE_2D, genTextures[0]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
// Fase 2
BitmapFactory.Options options = new BitmapFactory.Options();
options.inScaled = false;
Bitmap bitmap1 = BitmapFactory.decodeResource(context.getResources(), R.drawable.res_for_test_1, options);
// Fase 3
texImage2D(GL_TEXTURE_2D, 0, bitmap1, 0);
glGenerateMipmap(GL_TEXTURE_2D);
// Fase 4
aTextureLocation = glGetAttribLocation(program, "a_Texture");
uTextureLocation = glGetUniformLocation(program, "u_Texture");
glUniform1i(uTextureLocation, 0);
verticesInBuffer.position(2);
glEnableVertexAttribArray(aTextureLocation);
glVertexAttribPointer(aTextureLocation, 2, GL_FLOAT, false, 16, verticesInBuffer);
// ***** Texture stuff ends here </</</</
}
@Override
public void onSurfaceChanged(GL10 arg0, int width, int height) {
GLES20.glViewport(0, 0, width, height);
}
@Override
public void onDrawFrame(GL10 glUnused) {
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
glUseProgram(program);
verticesInBuffer.position(0);
glEnableVertexAttribArray(aPositionLocation);
glVertexAttribPointer(aPositionLocation, 2, GL_FLOAT, false, 16, verticesInBuffer);
glDrawArrays(GL_TRIANGLE_FAN, 0, 6);
}
}
解决方案
You need to specify active texture unit and assign a previously loaded texture to it.
For convenience, I've created a helper function which does all of this. It activates given texture unit, assigns texture with given ID to it and puts this value to sampler2D uniform of shader:
protected void setTexture2D(int textureUnit, int textureID, int uniformID) {
GLES20.glActiveTexture(GLES20.GL_TEXTURE0 + textureUnit);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureID);
GLES20.glUniform1i(uniformID, textureUnit);
}
And then call it like this:
setTexture2D(0, textureID, uniformID);
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