好的，我正在努力让教程在这里工作：http://lwjgl.org/wiki/index.php?title=GLSL_Shaders_with_LWJGL
我的问题是为什么我的着色器在这个例子中没有做任何事情？我对GLSL很新。
这是主类的代码
import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.util.glu.GLU;
/*
* Sets up the Display, the GL context, and runs the main game
loop.
*
* @author Stephen Jones
*/
public class GLSLTest{
Box box;
private boolean done=false; //game runs until done is set to true
public GLSLTest(){
init();
while(!done){
if(Display.isCloseRequested())
done=true;
render();
Display.update();
}
Display.destroy();
}
private void render(){
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT |
GL11.GL_DEPTH_BUFFER_BIT);
GL11.glLoadIdentity();
box.draw();
}
private void init(){
int w=1024;
int h=768;
try{
Display.setDisplayMode(new DisplayMode(w, h));
Display.setVSyncEnabled(true);
Display.setTitle("Shader Setup");
Display.create();
}catch(Exception e){
System.out.println("Error setting up display");
System.exit(0);
}
GL11.glViewport(0,0,w,h);
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GLU.gluPerspective(45.0f, ((float)w/(float)h),0.1f,100.0f);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glLoadIdentity();
GL11.glShadeModel(GL11.GL_SMOOTH);
GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
GL11.glClearDepth(1.0f);
GL11.glEnable(GL11.GL_DEPTH_TEST);
GL11.glDepthFunc(GL11.GL_LEQUAL);
GL11.glHint(GL11.GL_PERSPECTIVE_CORRECTION_HINT,
GL11.GL_NICEST);
box = new Box();
}
public static void main(String[] args){
new GLSLTest();
}
}
以下是Box类的代码：
import org.lwjgl.opengl.GL11;
import java.io.BufferedReader;
import java.io.FileReader;
import java.nio.ByteBuffer;
import java.nio.IntBuffer;
import org.lwjgl.BufferUtils;
import org.lwjgl.opengl.ARBShaderObjects;
import org.lwjgl.opengl.ARBVertexShader;
import org.lwjgl.opengl.ARBFragmentShader;
import org.lwjgl.opengl.Util;
/**
* The vertex and fragment shaders are setup when the box object is
* constructed. They are applied to the GL state prior to the box
* being drawn, and released from that state after drawing.
* @author Stephen Jones
*/
public class Box {
/*
* if the shaders are setup ok we can use shaders, otherwise we just
* use default settings
*/
private boolean useShader=true;
/*
* program shader, to which is attached a vertex and fragment shaders.
* They are set to 0 as a check because GL will assign unique int
* values to each
*/
private int shader=0;
private int vertShader=0;
private int fragShader=0;
public Box(){
/*
* create the shader program. If OK, create vertex
* and fragment shaders
*/
shader=ARBShaderObjects.glCreateProgramObjectARB();
if(shader!=0){
vertShader=createVertShader("screen.vert");
fragShader=createFragShader("screen.frag");
}
else useShader=false;
/*
* if the vertex and fragment shaders setup sucessfully,
* attach them to the shader program, link the sahder program
* (into the GL context I suppose), and validate
*/
if(vertShader !=0 && fragShader !=0){
ARBShaderObjects.glAttachObjectARB(shader, vertShader);
ARBShaderObjects.glAttachObjectARB(shader, fragShader);
ARBShaderObjects.glLinkProgramARB(shader);
ARBShaderObjects.glValidateProgramARB(shader);
useShader=printLogInfo(shader);
}else useShader=false;
}
/*
* If the shader was setup succesfully, we use the shader. Otherwise
* we run normal drawing code.
*/
public void draw(){
if(useShader) {
ARBShaderObjects.glUseProgramObjectARB(shader);
}
GL11.glLoadIdentity();
GL11.glTranslatef(0.0f, 0.0f, -10.0f);
GL11.glColor3f(1.0f, 1.0f, 1.0f);//white
GL11.glBegin(GL11.GL_QUADS);
GL11.glVertex3f(-1.0f, 1.0f, 0.0f);
GL11.glVertex3f(1.0f, 1.0f, 0.0f);
GL11.glVertex3f(1.0f, -1.0f, 0.0f);
GL11.glVertex3f(-1.0f, -1.0f, 0.0f);
GL11.glEnd();
//release the shader
ARBShaderObjects.glUseProgramObjectARB(0);
}
/*
* With the exception of syntax, setting up vertex and fragment shaders
* is the same.
* @param the name and path to the vertex shader
*/
private int createVertShader(String filename){
//vertShader will be non zero if succefully created
vertShader=ARBShaderObjects.glCreateShaderObjectARB(ARBVertexShader.GL_VERTEX_SHADER_ARB);
//if created, convert the vertex shader code to a String
if(vertShader==0){return 0;}
String vertexCode="";
String line;
try{
BufferedReader reader=new BufferedReader(new FileReader(filename));
while((line=reader.readLine())!=null){
vertexCode+=line + "\n";
}
}catch(Exception e){
System.out.println("Fail reading vertex shading code");
return 0;
}
/*
* associate the vertex code String with the created vertex shader
* and compile
*/
ARBShaderObjects.glShaderSourceARB(vertShader, vertexCode);
ARBShaderObjects.glCompileShaderARB(vertShader);
//if there was a problem compiling, reset vertShader to zero
if(!printLogInfo(vertShader)){
vertShader=0;
}
//if zero we won't be using the shader
return vertShader;
}
//same as per the vertex shader except for method syntax
private int createFragShader(String filename){
fragShader=ARBShaderObjects.glCreateShaderObjectARB(ARBFragmentShader.GL_FRAGMENT_SHADER_ARB);
if(fragShader==0){return 0;}
String fragCode="";
String line;
try{
BufferedReader reader=new BufferedReader(new FileReader(filename));
while((line=reader.readLine())!=null){
fragCode+=line + "\n";
}
}catch(Exception e){
System.out.println("Fail reading fragment shading code");
return 0;
}
ARBShaderObjects.glShaderSourceARB(fragShader, fragCode);
ARBShaderObjects.glCompileShaderARB(fragShader);
if(!printLogInfo(fragShader)){
fragShader=0;
}
return fragShader;
}
private static boolean printLogInfo(int obj){
IntBuffer iVal = BufferUtils.createIntBuffer(1);
ARBShaderObjects.glGetObjectParameterARB(obj,
ARBShaderObjects.GL_OBJECT_INFO_LOG_LENGTH_ARB, iVal);
int length = iVal.get();
if (length > 1) {
// We have some info we need to output.
ByteBuffer infoLog = BufferUtils.createByteBuffer(length);
iVal.flip();
ARBShaderObjects.glGetInfoLogARB(obj, iVal, infoLog);
byte[] infoBytes = new byte[length];
infoLog.get(infoBytes);
String out = new String(infoBytes);
System.out.println("Info log:\n"+out);
}
else return true;
return false;
}
}
以下是片段着色器的代码
varying vec4 vertColor;
void main(){
gl_FragColor = vertColor;
}
和顶点着色器：
varying vec4 vertColor;
void main(){
gl_Position = gl_ModelViewProjectionMatrix*gl_Vertex;
vertColor = vec4(0.6, 0.3, 0.4, 1.0);
}
这是我运行代码时得到的输出：
Info log:
Vertex shader was successfully compiled to run on hardware.
Info log:
Fragment shader was successfully compiled to run on hardware.
答案 0 :(得分：3)
问题是由于您在Info日志中看到了任何内容，即它正在产生成功的消息，这是一些OpenGL驱动程序倾向于这样做的方式。 printLogInfo也作为验证函数加倍，如果有任何日志信息则返回false，这告诉createVertShader和createFragShader将你的完美好的着色器id归零并返回失败。这真的不是一个好的设计，原因完全是这样的（我知道它来自其他人，所以我知道我不会亲自把你甩掉）。
此程序的快速解决方法是简单地使printLogInfo始终返回true。您最终需要做的是使用glGetShader（id，param）检查返回状态，如下所示：
glCompileShader(obj)
if (glGetShader(obj, GL_COMPILE_STATUS) == GL_FALSE
... handle error here ...
然后进行链接和验证：
glLinkProgram(obj)
if (glGetProgram(obj, GL_LINK_STATUS) == GL_FALSE
... handle error here ...
glValidateProgram(obj)
if (glGetProgram(obj, GL_VALIDATE_STATUS) == GL_FALSE
... handle error here ...
我不知道这些的ARB_ *等价物，对不起，但你可能应该使用OpenGL 2.0 API而不是ARB扩展来实现这个基本功能。任何仍然只支持着色器作为扩展的东西，无论如何都可能不值得使用着色器。
答案 1 :(得分：0)
着色器正在做他们应该做的事情。
不要考虑在视频游戏中听到的着色器，着色器只是直接访问GPU的一种方式。
您没有看到颜色差异的原因是由于未输出颜色这一事实，请尝试更改gl_fragColor的片段着色器中设置的内容。
如果您正在寻找有关着色器驱动的opengl的更多信息，我建议您查看在线图书
如果你谷歌那个标题，它应该是第一个结果。
希望这有帮助！