我正在尝试用opengl制作2D游戏。我制作了绘制网格的类。我制作了自己的Matrix4f类。我有3D opengl的经验。 当我将我的matrix4f传递给着色器时，它不会绘制。但是当我将它从三角形出现在屏幕上的位置乘以它时。我从我的3D游戏引擎尝试了我的Matrix4f，但它不能正常工作。 / p>
Matrix4f类
package com.game.main.maths;
import java.nio.FloatBuffer;
import com.game.main.util.Util;
public class Matrix4f {
private float[][] m;
public Matrix4f() {
m = new float[4][4];
initIdentity();
}
public Matrix4f initIdentity() {
for (int x = 0; x < 4; x++)
for (int y = 0; y < 4; y++) {
if (x == y)
m[x][y] = 1.0f;
else
m[x][y] = 0;
}
return this;
}
public Matrix4f translate(float x, float y, float z) {
initIdentity();
m[0][3] = x;
m[1][3] = y;
m[2][3] = z;
return this;
}
public Matrix4f translate(Vector3f pos) {
initIdentity();
m[0][3] = pos.getX();
m[1][3] = pos.getY();
m[2][3] = pos.getZ();
return this;
}
public Matrix4f rotate(float angle) {
initIdentity();
float rad = (float) Math.toRadians(angle);
float cos = (float) Math.cos(rad);
float sin = (float) Math.sin(rad);
m[0][0] = cos;
m[1][0] = sin;
m[0][1] = -sin;
m[1][1] = cos;
return this;
}
public Matrix4f initOrthographic(float left, float right, float bottom,
float top, float near, float far) {
initIdentity();
m[0][0] = 2.0f / (right - left);
m[1][1] = 2.0f / (top - bottom);
m[2][2] = 2.0f / (near - far);
m[0][3] = (left + right) / (left - right);
m[1][3] = (bottom + top) / (bottom - top);
m[2][3] = (near + far) / (far - near);
return this;
}
public Matrix4f mul(Matrix4f matrix) {
Matrix4f result = new Matrix4f();
for (int y = 0; y < 4; y++) {
for (int x = 0; x < 4; x++) {
float sum = 0.0f;
for (int index = 0; index < 4; index++)
sum += m[index][y] * matrix.get(x, index);
result.set(x, y, sum);
}
}
return result;
}
public float[][] getM() {
return m;
}
public float get(int x, int y) {
return m[x][y];
}
public void setM(float[][] m) {
this.m = m;
}
public void set(int x, int y, float value) {
m[x][y] = value;
}
public FloatBuffer toFloatBuffer() {
return Util.createFlippedBufferBuffer(this);
}
}
着色器类功能
public void setUniform(String uniformName, Matrix4f matrix){
int uniformLocation = getUniformLocation(uniformName);
glUniformMatrix4(uniformLocation, false, matrix.toFloatBuffer());
}
Util class
package com.game.main.util;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import com.game.main.graphics.Vertex;
import com.game.main.maths.Matrix4f;
public class Util {
public static FloatBuffer createFlippedBuffer(float[] data){
FloatBuffer buffer = ByteBuffer.allocateDirect(data.length * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
buffer.put(data).flip();
return buffer;
}
public static IntBuffer createFlippedBuffer(int[] data){
IntBuffer buffer = ByteBuffer.allocateDirect(data.length * 4).order(ByteOrder.nativeOrder()).asIntBuffer();
buffer.put(data).flip();
return buffer;
}
public static IntBuffer createIntBuffer(int size){
IntBuffer buffer = ByteBuffer.allocateDirect(size * 4).order(ByteOrder.nativeOrder()).asIntBuffer();
return buffer;
}
public static FloatBuffer createFloatBuffer(int size){
FloatBuffer buffer = ByteBuffer.allocateDirect(size * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
return buffer;
}
public static FloatBuffer createFlippedBufferBuffer(Matrix4f matrix){
FloatBuffer buffer = createFloatBuffer(4 * 4);
for(int x = 0; x < 4; x++)
for(int y = 0; y < 4; y++)
buffer.put(matrix.get(x, y));
buffer.flip();
return buffer;
}
public static FloatBuffer createFlippedBuffer(Vertex[] vertecies){
FloatBuffer buffer = createFloatBuffer(vertecies.length * Vertex.SIZE);
for(int i = 0; i < vertecies.length; i++){
buffer.put(vertecies[i].getPos().getX());
buffer.put(vertecies[i].getPos().getY());
buffer.put(vertecies[i].getPos().getZ());
buffer.put(vertecies[i].getTexCoord().getX());
buffer.put(vertecies[i].getTexCoord().getY());
}
buffer.flip();
return buffer;
}
}
初始化矩阵均匀
Matrix4f matrix = new Matrix4f().initOrthographic(0, 800, 0, 600, -1.0f, 1.0f);
Shader.Object.setUniform("mat", matrix);
顶点着色器
#version 330
layout(location = 0) in vec3 pos;
uniform mat4 mat;
void main(){
gl_Position = mat * vec4(pos, 1.0f);
}
网格类
package com.game.main.graphics;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL15.*;
import static org.lwjgl.opengl.GL20.*;
import com.game.main.util.Util;
public class Mesh {
private int vbo, ibo, size;
public Mesh(Vertex[] vertecies, int[] indices){
vbo = glGenBuffers();
ibo = glGenBuffers();
size = indices.length;
createMesh(vertecies, indices);
}
private void createMesh(Vertex[] vertecies, int[] indices){
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, Util.createFlippedBuffer(vertecies), GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(0, 3, GL_FLOAT, false, 5 * 4, 0);
glVertexAttribPointer(1, 2, GL_FLOAT, false, 5 * 4, 0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, Util.createFlippedBuffer(indices), GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}
public void bind(){
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
}
public void unbind(){
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}
public void drawWithBinding()
{
bind();
glDrawElements(GL_TRIANGLES, size, GL_UNSIGNED_INT, 0);
unbind();
}
public void draw(){
glDrawElements(GL_TRIANGLES, size, GL_UNSIGNED_INT, 0);
}
public void destroy(){
glDeleteBuffers(ibo);
glDeleteBuffers(vbo);
}
}
顶点类
package com.game.main.graphics;
import com.game.main.maths.Vector2f;
import com.game.main.maths.Vector3f;
public class Vertex {
private Vector3f pos = new Vector3f();
private Vector2f texCoord = new Vector2f();
public static final int SIZE = 5;
public Vertex(Vector3f pos){
this(pos, new Vector2f());
}
public Vertex(Vector3f pos, Vector2f texCoord){
this.pos = pos;
this.texCoord = texCoord;
}
public Vector3f getPos() {
return pos;
}
public void setPos(Vector3f pos) {
this.pos = pos;
}
public Vector2f getTexCoord() {
return texCoord;
}
public void setTexCoord(Vector2f texCoord) {
this.texCoord = texCoord;
}
}
转置代码
public Matrix4f transpose() {
float m00 = get(0, 0);
float m01 = get(1, 0);
float m02 = get(2, 0);
float m03 = get(3, 0);
float m10 = get(0, 1);
float m11 = get(1, 1);
float m12 = get(2, 1);
float m13 = get(3, 1);
float m20 = get(0, 2);
float m21 = get(1, 2);
float m22 = get(2, 2);
float m23 = get(3, 2);
float m30 = get(0, 3);
float m31 = get(1, 3);
float m32 = get(2, 3);
float m33 = get(3, 3);
set(0, 0, m00);
set(0, 1, m01);
set(0, 2, m02);
set(0, 3, m03);
set(1, 0, m10);
set(1, 1, m11);
set(1, 2, m12);
set(1, 3, m13);
set(2, 0, m20);
set(2, 1, m21);
set(2, 2, m22);
set(2, 3, m23);
set(3, 0, m30);
set(3, 1, m31);
set(3, 2, m32);
set(3, 3, m33);
return this;
}
游戏课
package com.game.main;
import static org.lwjgl.opengl.GL11.*;
import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import com.game.main.graphics.Mesh;
import com.game.main.graphics.Shader;
import com.game.main.graphics.Vertex;
import com.game.main.maths.Matrix4f;
import com.game.main.maths.Vector3f;
public class Game{
private boolean running = false;
private Mesh mesh;
public Game(int width, int height){
try {
Display.setDisplayMode(new DisplayMode(800, 600));
Display.setTitle("2D Game");
Display.create();
} catch (LWJGLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Matrix4f matrix = new Matrix4f().initOrthographic(-1, 1, -1, 1, -1.0f, 1.0f);
Shader.Object.setUniform("mat", matrix);
Vertex[] vertecies = new Vertex[]{
new Vertex(new Vector3f(0.5f, 0.5f, 0)),
new Vertex(new Vector3f(0.5f, 0,0)),
new Vertex(new Vector3f(0, 0.5f,0)),
new Vertex(new Vector3f(0.5f, 0,0))
};
/*float[] vertecies = new float[]{
-10f, -10f * 9.0f / 16.0f, 1,
-10f, 10f * 9.0f / 16.0f,1,
0, 10f * 9.0f / 1.0f,1,
0, -10f * 9.0f / 6.0f,1
};*/
int[] ind = new int[]{
0, 1, 2,
2, 3, 0
};
mesh = new Mesh(vertecies, ind);
}
private void init(){
glEnable(GL_DEPTH_TEST);
}
public void start(){
if(running)
return;
running = true;
gameLoop();
}
public void stop(){
if(!running)
return;
running = false;
}
private void gameLoop(){
init();
long timer = System.currentTimeMillis();
long lastTime = System.nanoTime();
double delta = 0;
int frames = 0, updates = 0;
while(running){
long now = System.nanoTime();
delta += (now - lastTime) / (1000000000.0 / 60.0);
lastTime = now;
while(delta >= 1){
if(Display.isCloseRequested())
stop();
update();
updates++;
delta--;
}
render();
frames++;
if(System.currentTimeMillis() - timer >= 1000){
timer += 1000;
Display.setTitle("Frames: "+frames+" Updates: "+updates);
frames = updates = 0;
}
}
destroy();
}
private void update(){
}
private void render(){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
Shader.Object.bind();
mesh.drawWithBinding();
Shader.Object.unbind();
Display.update();
}
private void destroy(){
mesh.destroy();
Display.destroy();
}
}
答案 0 :(得分：1)
似乎问题在于设置矩阵是否均匀。 OpenGL是一个状态机，并不记得统一的值。更重要的是，在着色器正在使用时必须调用 glUniformMatrix4 。
目前，矩阵只在初始化时设置（在Game构造函数中），当它需要在render()时。
Shader.Object.bind(); //glUseProgram(programHandle)
Shader.Object.setUniform(...) //glUniformMatrix4
mesh.drawWithBinding(); //glDrawElements
Shader.Object.unbind(); //glUseProgram(0), but not necessary unless you want fixed function rendering
如果没有设置mat，那么它可能是一个零矩阵，阻止绘图。
除上述内容外，还有其他两个潜在问题：
查看屏幕左下方，查看该像素是否已开启。我怀疑一切都在运作，just really small。如果以下工作：
gl_Position = vec4(pos, 1.0f);
基本上乘以单位矩阵并且几乎ortho(-1,1,-1,1,-1,1)（除了正交调用给出mat[2][2]=-1），然后我猜测你的网格大约是单位立方体的大小。
介绍mat = initOrthographic(0, 800, 0, 600, -1.0f, 1.0f)看起来像是以像素为单位给出顶点的场景。原点将位于左下角，如果网格适合单位立方体，则最多可绘制一个像素。
请参阅@ Jerem关于行/列主要矩阵的答案。
答案 1 :(得分：0)
看起来你的矩阵是行主要的。在将其发送到着色器之前，您需要对其进行转置。
请注意，在glUniformMatrix4f中有一个名为transpose的布尔参数，但你不能在opengl中使用它 - 文档说它必须是假的 - 你必须自己转置它。