我试图用OpenGL ES 2.0绘制文本和正方形。 每个人都可以在任何位置。投影问题 - 绘图文本和正方形
但到目前为止,我只能看到这取决于投影模式其中的一个,我选择:
- 我只看到了广场上,如果我用“Matrix.setLookAtM”使相机(0,-3 ,0)看(0,0,0)
- 我只看到文本,如果我使用 “Matrix.orthoM” 为具有正交投影从 “Texample2Renderer.java”
CF代码在底部。
我想看到两者,它怎么可能?我正在考虑修改Square类以使其适用于正交投影模式,但我不知道如何去做。
对于文本,我使用这个代码(有很多的代码,所以我更喜欢后回购):
https://github.com/d3alek/Texample2
而且为方形,我使用这个代码:
public class Square {
// number of coordinates per vertex in this array
static final int COORDS_PER_VERTEX = 3;
static float squareCoords[] = {
-0.5f, 0.5f, 0.0f, // top left
-0.5f, -0.5f, 0.0f, // bottom left
0.5f, -0.5f, 0.0f, // bottom right
0.5f, 0.5f, 0.0f}; // top right
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 final short drawOrder[] = {0, 1, 2, 0, 2, 3}; // order to draw vertices
private final int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex
float color[] = {0.2f, 0.709803922f, 0.898039216f, 1.0f};
private int mPositionHandle;
private int mColorHandle;
private int mMVPMatrixHandle;
/**
* Sets up the drawing object data for use in an OpenGL ES context.
*/
public Square() {
// BUFFER FOR SQUARE COORDS
// initialize vertex byte buffer for shape coordinates
ByteBuffer bb = ByteBuffer.allocateDirect(
// (# of coordinate values * 4 bytes per float)
squareCoords.length * 4);
bb.order(ByteOrder.nativeOrder());
vertexBuffer = bb.asFloatBuffer();
vertexBuffer.put(squareCoords);
vertexBuffer.position(0);
// BUFFER FOR DRAW ORDER
// initialize byte buffer for the draw list
ByteBuffer dlb = ByteBuffer.allocateDirect(
// (# of coordinate values * 2 bytes per short)
drawOrder.length * 2);
dlb.order(ByteOrder.nativeOrder());
drawListBuffer = dlb.asShortBuffer();
drawListBuffer.put(drawOrder);
drawListBuffer.position(0);
// prepare shaders and OpenGL program
int vertexShader = Utilities.loadShader(
GLES20.GL_VERTEX_SHADER,
vertexShaderCode);
int fragmentShader = Utilities.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
}
/**
* 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");
//Utilities.checkEglErrorEGL14Android("glGetUniformLocation");
// Apply the projection and view transformation
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mvpMatrix, 0);
//Utilities.checkEglErrorEGL14Android("glUniformMatrix4fv");
// Draw the square
GLES20.glDrawElements(
GLES20.GL_TRIANGLES, drawOrder.length,
GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
// Disable vertex array
GLES20.glDisableVertexAttribArray(mPositionHandle);
}
}
Texample2Renderer.java:
public class Texample2Renderer implements GLSurfaceView.Renderer {
private static final String TAG = "TexampleRenderer";
private Square square;
private GLText glText; // A GLText Instance
private Context context; // Context (from Activity)
private int width = 100; // Updated to the Current Width + Height in onSurfaceChanged()
private int height = 100;
private float[] mProjMatrix = new float[16];
private float[] mVMatrix = new float[16];
private float[] mVPMatrix = new float[16];
private boolean usesOrtho = false;
public Texample2Renderer(Context context) {
super();
this.context = context; // Save Specified Context
}
public void onSurfaceCreated(GL10 unused, EGLConfig config) {
// Set the background frame color
GLES20.glClearColor(0.4f, 0.3f, 0.6f, 1.0f);
// Create the GLText
glText = new GLText(context.getAssets());
square = new Square();
// Load the font from file (set size + padding), creates the texture
// NOTE: after a successful call to this the font is ready for rendering!
glText.load("Roboto-Regular.ttf", 20*3, 2, 2); // Create Font (Height: 14 Pixels/X+Y Padding 2 Pixels)
// enable texture + alpha blending
GLES20.glEnable(GLES20.GL_BLEND);
GLES20.glBlendFunc(GLES20.GL_ONE, GLES20.GL_ONE_MINUS_SRC_ALPHA);
}
public void onSurfaceChanged(GL10 unused, int width, int height) { // gl.glViewport(0, 0, width, height);
GLES20.glViewport(0, 0, width, height);
float ratio = (float) width/height;
// Take into account device orientation
if (width > height) {
Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 1, 10);
}
else {
Matrix.frustumM(mProjMatrix, 0, -1, 1, -1/ratio, 1/ratio, 1, 10);
}
// Save width and height
this.width = width; // Save Current Width
this.height = height; // Save Current Height
if(usesOrtho) {
int useForOrtho = Math.min(width, height);
//TODO: Is this wrong?
Matrix.orthoM(mVMatrix, 0,
-useForOrtho/2,
useForOrtho/2,
-useForOrtho/2,
useForOrtho/2, 0.1f, 100f);
}
}
public void onDrawFrame(GL10 unused) {
// Redraw background color
int clearMask = GLES20.GL_COLOR_BUFFER_BIT;
GLES20.glClear(clearMask);
if(!usesOrtho)
Matrix.setLookAtM(mVMatrix,
0, // offset
0, 0, -3f, // eye (camera's position)
0f, 0f, 0f, // center (where to look at)
0f, 1.0f, 0.0f); // up
Matrix.multiplyMM(mVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);
if(square != null)
square.draw(mVPMatrix);
// TEST: render the entire font texture
glText.drawTexture(width/2, height/2, mVPMatrix); // Draw the Entire Texture
// TEST: render some strings with the font
glText.begin(1.0f, 1.0f, 1.0f, 1.0f, mVPMatrix); // Begin Text Rendering (Set Color WHITE)
glText.drawC("Test String 3D!", 0f, 0f, 0f, 0, -30, 0);
// glText.drawC("Test String :)", 0, 0, 0); // Draw Test String
glText.draw("Diagonal 1", 40, 40, 40); // Draw Test String
glText.draw("Column 1", 100, 100, 90); // Draw Test String
glText.end(); // End Text Rendering
glText.begin(0.0f, 0.0f, 1.0f, 1.0f, mVPMatrix); // Begin Text Rendering (Set Color BLUE)
glText.draw("More Lines...", 50, 200); // Draw Test String
glText.draw("The End.", 50, 200 + glText.getCharHeight(), 180); // Draw Test String
glText.end(); // End Text Rendering
}
}
我刚刚改性的用Texample2Renderer.java中的代码绘制一个正方形。我还添加了一个布尔值来在投影模式之间切换。
任何帮助将不胜感激,多谢提前!