我有这个程序：
package com.laytonlabs.android.levelup.shapes;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.ShortBuffer;
import java.util.ArrayList;
import android.opengl.GLES20;
import com.laytonlabs.android.levelup.MyGLRenderer;
import com.laytonlabs.android.levelup.Vec2;
import com.laytonlabs.android.levelup.game.Cell;
/**
* A two-dimensional square for use as a drawn object in OpenGL ES 2.0.
*/
public abstract class Shape {
private final String TAG = "Shape";
private final String vertexShaderCode =
// This matrix member variable provides a hook to manipulate
// the coordinates of the objects that use this vertex shader
"uniform mat4 uMVPMatrix;" +
"attribute vec4 vPosition;" +
"void main() {" +
// The matrix must be included as a modifier of gl_Position.
// Note that the uMVPMatrix factor *must be first* in order
// for the matrix multiplication product to be correct.
" gl_Position = uMVPMatrix * vPosition;" +
"}";
private final String fragmentShaderCode =
"precision mediump float;" +
"uniform vec4 vColor;" +
"void main() {" +
" gl_FragColor = vColor;" +
"}";
private final FloatBuffer vertexBuffer;
private final ShortBuffer drawListBuffer;
private final int mProgram;
private int mPositionHandle;
private int mColorHandle;
private int mMVPMatrixHandle;
protected float[] shapeCoords;
private final int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex
// number of coordinates per vertex in this array
static final int COORDS_PER_VERTEX = 3;
//These will be initiated by the abstract class
private final float[] ORIGINAL_COORDS;
private final short[] DRAW_ORDER; // order to draw vertices
//#RGB: white (255, 255, 255)
private final float[] COLOR;
//Sets the scale of the shape and where the X centre is.
private final float SCALE;
private final float CENTRE_X;
private final float CENTRE_Y;
public abstract float getCentreX();
public abstract float getCentreY();
public float[] getNestedTextColor() {
return null;
}
public void setNestedTextColor(float[] textColor) {}
public Cell getCell() {
return null;
}
public ArrayList<Shape> getShapes() {
return null;
}
public void setShapes(float scale, String nestedText) {}
public void setShapes(float scale, String nestedText, float[] textColor) {}
public boolean intersects(Vec2 touchCoords) {
return false;
}
public float getMinX() {return getMin(getArraySubset(0));}
public float getMaxX() {return getMax(getArraySubset(0));}
public float getMinY() {return getMin(getArraySubset(1));}
public float getMaxY() {return getMax(getArraySubset(1));}
private float getMin(float[] values) {
float minVal = 1000f;
for (float value : values) {
if (value < minVal) {
minVal = value;
}
}
return minVal;
}
private float getMax(float[] values) {
float maxVal = -1000f;
for (float value : values) {
if (value > maxVal) {
maxVal = value;
}
}
return maxVal;
}
private float[] getArraySubset(int offset) {
if (shapeCoords == null || shapeCoords.length == 0) {
return null;
}
float[] subsetArray = new float[shapeCoords.length / COORDS_PER_VERTEX];
int subsetIndex = 0;
for (int i = offset; i < shapeCoords.length; i=(i+COORDS_PER_VERTEX)) {
subsetArray[subsetIndex] = shapeCoords[i];
subsetIndex++;
}
return subsetArray;
}
/**
* Sets up the drawing object data for use in an OpenGL ES context.
*/
public Shape(float[] originalCoords, short[] drawOrder, float[] color,
float scale, float centreX, float centreY) {
this.ORIGINAL_COORDS = originalCoords;
this.DRAW_ORDER = drawOrder;
this.COLOR = color;
this.SCALE = scale;
this.CENTRE_X = centreX;
this.CENTRE_Y = centreY;
this.shapeCoords = ORIGINAL_COORDS.clone();
adjustShape(scale, centreX, centreY);
//Resize based on the scale
//adjustSize(scale);
// initialize vertex byte buffer for shape coordinates
ByteBuffer bb = ByteBuffer.allocateDirect(
// (# of coordinate values * 4 bytes per float)
shapeCoords.length * 4);
bb.order(ByteOrder.nativeOrder());
vertexBuffer = bb.asFloatBuffer();
vertexBuffer.put(shapeCoords);
vertexBuffer.position(0);
// initialize byte buffer for the draw list
ByteBuffer dlb = ByteBuffer.allocateDirect(
// (# of coordinate values * 2 bytes per short)
DRAW_ORDER.length * 2);
dlb.order(ByteOrder.nativeOrder());
drawListBuffer = dlb.asShortBuffer();
drawListBuffer.put(DRAW_ORDER);
drawListBuffer.position(0);
// prepare shaders and OpenGL program
int vertexShader = MyGLRenderer.loadShader(
GLES20.GL_VERTEX_SHADER,
vertexShaderCode);
int fragmentShader = MyGLRenderer.loadShader(
GLES20.GL_FRAGMENT_SHADER,
fragmentShaderCode);
mProgram = GLES20.glCreateProgram(); // create empty OpenGL Program
GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader to program
GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program
GLES20.glLinkProgram(mProgram); // create OpenGL program executables
}
//Adjust the original scale of the shape and position
private void adjustShape(float scale, float centreX, float centreY) {
for (int i = 0; i < shapeCoords.length; i++) {
//Apply the scale
shapeCoords[i] = (ORIGINAL_COORDS[i] * scale);
//Apply the x offset
shapeCoords[i] += (i % 3 == 0 ? centreX : 0);
//Apply the y offset
shapeCoords[i] += (i % 3 == 1 ? centreY : 0);
}
}
/**
* Encapsulates the OpenGL ES instructions for drawing this shape.
*
* @param mvpMatrix - The Model View Project matrix in which to draw
* this shape.
*/
public void draw(float[] mvpMatrix) {
// Add program to OpenGL environment
GLES20.glUseProgram(mProgram);
// get handle to vertex shader's vPosition member
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
// Enable a handle to the triangle vertices
GLES20.glEnableVertexAttribArray(mPositionHandle);
// Prepare the triangle coordinate data
GLES20.glVertexAttribPointer(
mPositionHandle, COORDS_PER_VERTEX,
GLES20.GL_FLOAT, false,
vertexStride, vertexBuffer);
// get handle to fragment shader's vColor member
mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");
// Set color for drawing the triangle
GLES20.glUniform4fv(mColorHandle, 1, COLOR, 0);
// get handle to shape's transformation matrix
mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
MyGLRenderer.checkGlError("glGetUniformLocation");
// Apply the projection and view transformation
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mvpMatrix, 0);
MyGLRenderer.checkGlError("glUniformMatrix4fv");
// Draw the square
GLES20.glDrawElements(
GLES20.GL_TRIANGLES, DRAW_ORDER.length,
GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
// Disable vertex array
GLES20.glDisableVertexAttribArray(mPositionHandle);
}
}
我使用此命令#include <iostream>
#include <fstream>
using namespace std;
int main (int argc, char** argv)
{
ifstream infile("argv[1]");
int testNumber = 0;
infile >> testNumber;
cout << testNumber << '\n';
}
./program myfile.txt包含一些由空格和新行分隔的整数
我希望程序输出文件中的第一个数字，但它总是打印myfile.txt。我做错了什么？
答案 0 :(得分：3)
ifstream infile("argv[1]");
查找名为argv[1]的文件，而不是myfile.txt。要使用程序参数，请删除引号：
ifstream infile(argv[1]);