package se.embargo.onebit.shader;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import se.embargo.core.graphics.ShaderProgram;
import se.embargo.onebit.R;
import android.graphics.SurfaceTexture;
import android.hardware.Camera;
import android.opengl.GLES11Ext;
import android.opengl.GLES20;
import android.opengl.Matrix;
import android.util.Log;
public class PreviewShader implements IRenderStage, SurfaceTexture.OnFrameAvailableListener {
public static final int SHADER_SOURCE_ID = R.raw.image_vertex_shader;
private static final String TAG = "PreviewShader";
private static final int FLOAT_SIZE_BYTES = 4;
private static final int TRIANGLE_VERTICES_DATA_STRIDE_BYTES = 5 * FLOAT_SIZE_BYTES;
private static final int TRIANGLE_VERTICES_DATA_POS_OFFSET = 0;
private static final int TRIANGLE_VERTICES_DATA_UV_OFFSET = 3;
private ShaderProgram _program;
private final float[] _vertices = {
// X, Y, Z, U, V
-1.0f, 1.0f, 0.0f, 0.0f, 1.0f, // Top left
1.0f, 1.0f, 0.0f, 1.0f, 1.0f, // Top right
-1.0f, -1.0f, 0.0f, 0.0f, 0.0f, // Bottom left
1.0f, -1.0f, 0.0f, 1.0f, 0.0f // Bottom right
};
private FloatBuffer _vertexbuf;
private int _previewTextureHandle, _previewTextureLocation;
private SurfaceTexture _previewTexture;
private boolean _updateSurface = false;
private int muMVPMatrixHandle;
private int maPositionHandle;
private int maTextureCoordHandle;
private int muSTMatrixHandle;
private int muCRatioHandle;
private float[] mMVPMatrix = new float[16];
private float[] mVMatrix = new float[16];
private float[] mSTMatrix = new float[16];
private float[] mProjMatrix = new float[16];
private float _cRatio;
/**
* @param program Shader program built from SHADER_SOURCE_ID
* @param size Size of camera preview frames
*/
public PreviewShader(ShaderProgram program, Camera.Size previewSize, int surfaceWidth, int surfaceHeight) {
_program = program;
_cRatio = (float)previewSize.width / previewSize.height;
// Allocate buffer to hold vertices
_vertexbuf = ByteBuffer.allocateDirect(_vertices.length * FLOAT_SIZE_BYTES).order(ByteOrder.nativeOrder()).asFloatBuffer();
_vertexbuf.put(_vertices).position(0);
// Find handles to shader parameters
maPositionHandle = _program.getAttributeLocation("aPosition");
maTextureCoordHandle = _program.getAttributeLocation("aTextureCoord");
muMVPMatrixHandle = _program.getUniformLocation("uMVPMatrix");
muSTMatrixHandle = _program.getUniformLocation("uSTMatrix");
muCRatioHandle = _program.getUniformLocation("uCRatio");
_previewTextureLocation = _program.getUniformLocation("sTexture");
// Create the external texture which the camera preview is written to
int[] textures = new int[1];
GLES20.glGenTextures(textures.length, textures, 0);
_previewTextureHandle = textures[0];
_previewTexture = new SurfaceTexture(_previewTextureHandle);
_previewTexture.setOnFrameAvailableListener(this);
GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, _previewTextureHandle);
checkGlError("glBindTexture");
// No mip-mapping with camera source
GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
// Clamp to edge is only option
GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
/*
Bitmap bm = BitmapFactory.decodeResource(_context.getResources(), R.raw.david);
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bm, 0);
*/
// Set the viewpoint
Matrix.setLookAtM(mVMatrix, 0, 0, 0, 1.45f, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
Matrix.setIdentityM(mSTMatrix, 0);
// Set the screen ratio projection
float ratio = (float)surfaceWidth / surfaceHeight;
Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 1f, 10);
// Apply the screen ratio projection
Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);
}
public SurfaceTexture getPreviewTexture() {
return _previewTexture;
}
@Override
public void draw() {
// Check if a new frame is available
synchronized (this) {
if (_updateSurface) {
_previewTexture.updateTexImage();
_previewTexture.getTransformMatrix(mSTMatrix);
_updateSurface = false;
}
}
// Transfer the screen ratio projection
GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, mMVPMatrix, 0);
GLES20.glUniformMatrix4fv(muSTMatrixHandle, 1, false, mSTMatrix, 0);
GLES20.glUniform1f(muCRatioHandle, _cRatio);
// Bind the preview texture
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, _previewTextureHandle);
GLES20.glUniform1i(_previewTextureLocation, 0);
checkGlError("glBindTexture");
// Prepare the triangles
_vertexbuf.position(TRIANGLE_VERTICES_DATA_POS_OFFSET);
GLES20.glVertexAttribPointer(
maPositionHandle, 3, GLES20.GL_FLOAT, false,
TRIANGLE_VERTICES_DATA_STRIDE_BYTES, _vertexbuf);
checkGlError("glVertexAttribPointer maPosition");
GLES20.glEnableVertexAttribArray(maPositionHandle);
checkGlError("glEnableVertexAttribArray maPositionHandle");
_vertexbuf.position(TRIANGLE_VERTICES_DATA_UV_OFFSET);
GLES20.glVertexAttribPointer(
maTextureCoordHandle, 2, GLES20.GL_FLOAT, false,
TRIANGLE_VERTICES_DATA_STRIDE_BYTES, _vertexbuf);
checkGlError("glVertexAttribPointer maTextureHandle");
GLES20.glEnableVertexAttribArray(maTextureCoordHandle);
checkGlError("glEnableVertexAttribArray maTextureHandle");
// Draw two triangles to form a square
GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 3);
GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 1, 3);
checkGlError("glDrawArrays");
}
@Override
public synchronized void onFrameAvailable(SurfaceTexture surfaceTexture) {
_updateSurface = true;
}
private void checkGlError(String op) {
int error;
while ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR) {
Log.e(TAG, op + ": glError " + error);
throw new RuntimeException(op + ": glError " + error);
}
}
}
