Hello,
I have been using an implementation of GLSL shaders that consists of a lot of hard coding along with the vert/frag shader code.
I came across a java class for glsl shaders which seems to make loading shaders a snap. My only problem is that I can’t seem to finc much about converting java to c.
Anyway, here is an example. (Java Class code at the end)
The simple call for initializing the shader.
import GLShaders; //our shader wrapper
public int basicShader; //an integer reference to our shader
basicShader = GLShaders.loadShadersCode("basic.vert","basic.frag");
myTexture = TextureLoader.get().getTexture("anyTextureIWant.tga");
GL20.glUseProgram(basicShader); //start using this shader
GL13.glActiveTexture(GL13.GL_TEXTURE0);
GL11.glBindTexture(GL11.GL_TEXTURE_2D, myTexture.getTextureID());
GLShaders.sendUniform1i(basicShader, "myTexture",0);
Fog Vertex Shader
uniform vec3 CameraPosition;// the current camera position (x,y,z)
varying float Distance;// the distance we will send forward
void main()
{
vec4 a = gl_Vertex;
float dx = a.x - CameraPosition.x;
float dy = a.y - CameraPosition.y;
float dz = a.z - CameraPosition.z;
Distance = clamp((dx*dx)+(dy*dy)+(dz*dz),0.0,50000.0);
gl_TexCoord[0] = gl_MultiTexCoord0;
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}
Fog Fragment Shader
varying float Distance;
uniform sampler2D TheTexture;
void main (void)
{
vec4 color= texture2D(TheTexture, gl_TexCoord[0].st);
gl_FragColor = mix(color, vec4(0.5, 0.5, 0.5, 1), Distance/50000.0);
}
See how simple that is to use fog? It’s 95% smaller than the current code I’ve been using. Here is the java class that is actually used above.
package MyPackage;
/* *Author: Abdul Bezrati *Email: [email]abezrati@hotmail.com[/email] */
/* Fixed Memory leaks due to too many bytebuffers - TheSmit email: [email]TheSmit@warmtart.co.uk[/email] */
import org.lwjgl.opengl.ARBFragmentProgram;
import org.lwjgl.opengl.ARBVertexProgram;
import org.lwjgl.opengl.ARBShaderObjects;
import org.lwjgl.opengl.ARBFragmentShader;
import org.lwjgl.opengl.ARBVertexShader;
import org.lwjgl.opengl.GL11;
import java.io.FileInputStream;
import java.io.DataInputStream;
import java.io.InputStream;
import org.lwjgl.BufferUtils;
import java.nio.FloatBuffer;
import java.nio.ByteBuffer;
import java.nio.IntBuffer;
public class GLShaders{
static ByteBuffer buffer= BufferUtils.createByteBuffer(1024);;
private static boolean VPSupported = false, FPSupported = false, VSSupported = false, FSSupported = false;
private static IntBuffer logBuffer = BufferUtils.createIntBuffer(1);
static{ VPSupported = checkExtensionSupport("GL_ARB_vertex_program");
FPSupported = checkExtensionSupport("GL_ARB_fragment_program");
VSSupported = checkExtensionSupport("GL_ARB_vertex_shader");
FSSupported = checkExtensionSupport("GL_ARB_fragment_shader");
}
private static boolean checkExtensionSupport(String extension){
String supportedExtensions = GL11.glGetString(GL11.GL_EXTENSIONS);
return supportedExtensions.indexOf(extension) != -1;
}
public static int loadProgramCode(String filename, boolean isFragment){
if(isFragment && !FPSupported){
System.out.println("GL_ARB_fragment_program is not supported, skipping.");
return 0;
}
else if(!VPSupported){
System.out.println("GL_ARB_vertex_program is not supported, skipping.");
return 0;
}
ByteBuffer shaderPro = getProgramCode(filename);
IntBuffer id = BufferUtils.createIntBuffer(1);
if(isFragment){
ARBFragmentProgram.glGenProgramsARB(id);
ARBFragmentProgram.glBindProgramARB(ARBFragmentProgram.GL_FRAGMENT_PROGRAM_ARB , id.get(0));
ARBFragmentProgram.glProgramStringARB(ARBFragmentProgram.GL_FRAGMENT_PROGRAM_ARB, ARBFragmentProgram.GL_PROGRAM_FORMAT_ASCII_ARB, shaderPro);
System.out.println(GL11.glGetString(ARBFragmentProgram.GL_PROGRAM_ERROR_STRING_ARB));
}
else{
ARBVertexProgram.glGenProgramsARB(id);
ARBVertexProgram.glBindProgramARB(ARBVertexProgram.GL_VERTEX_PROGRAM_ARB , id.get(0));
ARBVertexProgram.glProgramStringARB(ARBVertexProgram.GL_VERTEX_PROGRAM_ARB, ARBVertexProgram.GL_PROGRAM_FORMAT_ASCII_ARB, shaderPro);
System.out.println(GL11.glGetString(ARBVertexProgram.GL_PROGRAM_ERROR_STRING_ARB));
}
return id.get(0);
}
public static int loadShadersCode(String vertexShaderFile, String fragmentShaderFile){
if(!FSSupported || !VSSupported){
System.out.println("GL_ARB_fragment_shader or GL_ARB_vertex_shader is not supported, skipping.");
return 0;
}
ByteBuffer vertexShader = getProgramCode(vertexShaderFile), fragmentShader = getProgramCode(fragmentShaderFile);
int vertexShaderID = 0, fragmentShaderID = 0, linkedShadersID = 0;
vertexShaderID = ARBShaderObjects.glCreateShaderObjectARB(ARBVertexShader.GL_VERTEX_SHADER_ARB);
ARBShaderObjects.glShaderSourceARB(vertexShaderID, vertexShader);
ARBShaderObjects.glCompileShaderARB(vertexShaderID);
printShaderObjectInfoLog(vertexShaderFile, vertexShaderID);
ARBShaderObjects.glGetObjectParameterARB(vertexShaderID, ARBShaderObjects.GL_OBJECT_COMPILE_STATUS_ARB, logBuffer);
if(logBuffer.get(0) == GL11.GL_FALSE ){
System.out.println("Error in vertex shader");
return 0;
}
fragmentShaderID = ARBShaderObjects.glCreateShaderObjectARB(ARBFragmentShader.GL_FRAGMENT_SHADER_ARB);
ARBShaderObjects.glShaderSourceARB(fragmentShaderID, fragmentShader);
ARBShaderObjects.glCompileShaderARB(fragmentShaderID);
printShaderObjectInfoLog(fragmentShaderFile, fragmentShaderID);
ARBShaderObjects.glGetObjectParameterARB(fragmentShaderID, ARBShaderObjects.GL_OBJECT_COMPILE_STATUS_ARB, logBuffer);
if(logBuffer.get(0) == GL11.GL_FALSE ){
System.out.println("Error in fragment shader");
return 0;
}
linkedShadersID = ARBShaderObjects.glCreateProgramObjectARB();
ARBShaderObjects.glAttachObjectARB(linkedShadersID, vertexShaderID);
ARBShaderObjects.glAttachObjectARB(linkedShadersID, fragmentShaderID);
ARBShaderObjects.glLinkProgramARB(linkedShadersID);
printShaderProgramInfoLog(linkedShadersID);
ARBShaderObjects.glGetObjectParameterARB(linkedShadersID, ARBShaderObjects.GL_OBJECT_LINK_STATUS_ARB, logBuffer);
if(logBuffer.get(0) == GL11.GL_FALSE ){
System.out.println("Error in linking shaders");
return 0;
}
System.out.println("Vertex and Fragment shaders linked OK.");
return linkedShadersID;
}
public static void sendUniform1i(int id, String name, int value){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform1iARB(location, value);
}
public static void sendUniform2i(int id, String name, int value1, int value2){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform2iARB(location, value1, value2);
}
public static void sendUniform3i(int id, String name, int value1, int value2, int value3){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform3iARB(location, value1, value2, value3);
}
public static void sendUniform4i(int id, String name, int value1, int value2, int value3, int value4){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform4iARB(location, value1, value2, value3, value4);
}
public static void sendUniform1f(int id, String name, float value){
int location = getUniformLocation(id, name); if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform1fARB(location, value);
}
public static void sendUniform2f(int id, String name, float value1, float value2){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform2fARB(location, value1, value2);
}
public static void sendUniform3f(int id, String name, float value1, float value2, float value3){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform3fARB(location, value1, value2, value3);
}
public static void sendUniform4f(int id, String name, float value1, float value2, float value3, float value4){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform4fARB(location, value1, value2, value3, value4);
}
public static void sendUniform1FB(int id, String name, FloatBuffer values){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform1ARB(location, values);
}
public static void sendUniform2FB(int id, String name, FloatBuffer values){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform2ARB(location, values);
}
public static void sendUniform3FB(int id, String name, FloatBuffer values){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform3ARB(location, values);
}
public static void sendUniform4FB(int id, String name, FloatBuffer values){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform4ARB(location, values);
}
public static void sendUniform1IB(int id, String name, IntBuffer values){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform1ARB(location, values);
}
public static void sendUniform2IB(int id, String name, IntBuffer values){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform2ARB(location, values);
}
public static void sendUniform3IB(int id, String name, IntBuffer values){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform3ARB(location, values);
}
public static void sendUniform4IB(int id, String name, IntBuffer values){
int location = getUniformLocation(id, name);
if(checkGLError(location, name)== 0) return;
ARBShaderObjects.glUniform4ARB(location, values);
}
private static int getUniformLocation(int id, String name) {
buffer.clear();
buffer.put(name.getBytes());
buffer.put((byte)0);
buffer.flip();
return ARBShaderObjects.glGetUniformLocationARB(id, buffer);
}
private static void printShaderObjectInfoLog(String file, int ID) {
ARBShaderObjects.glGetObjectParameterARB(ID, ARBShaderObjects.GL_OBJECT_INFO_LOG_LENGTH_ARB, logBuffer);
final int logLength = logBuffer.get(0);
if( logLength <= 1 ) return;
final ByteBuffer log = BufferUtils.createByteBuffer(logLength);
ARBShaderObjects.glGetInfoLogARB(ID, null, log);
byte[] byteArray = new byte[logLength];
log.get(byteArray);
System.out.println("
Info Log of Shader Object: " + file);
System.out.println("--------------------------");
System.out.println(new String(byteArray));
}
private static void printShaderProgramInfoLog(int ID) {
ARBShaderObjects.glGetObjectParameterARB(ID, ARBShaderObjects.GL_OBJECT_INFO_LOG_LENGTH_ARB, logBuffer);
final int logLength = logBuffer.get(0);
if(logLength <= 1 ) return;
final ByteBuffer log = BufferUtils.createByteBuffer(logLength);
ARBShaderObjects.glGetInfoLogARB(ID, null, log);
byte[] byteArray = new byte[logLength];
log.get(byteArray);
System.out.println("
Shader Program Info Log: ");
System.out.println("--------------------------");
System.out.println(new String(byteArray));
}
private static ByteBuffer getProgramCode(String filename){ ClassLoader fileLoader = GLShaders.class.getClassLoader();
InputStream fileInputStream = fileLoader.getResourceAsStream(filename);
byte[] shaderCode = null;
try{
if(fileInputStream == null) fileInputStream = new FileInputStream(filename);
DataInputStream dataStream = new DataInputStream(fileInputStream);
dataStream.readFully(shaderCode = new byte[fileInputStream.available()]);
fileInputStream.close();
dataStream.close();
}
catch(Exception e ){
System.out.println(e.getMessage());
}
ByteBuffer shaderPro = BufferUtils.createByteBuffer(shaderCode.length) .put(shaderCode);
shaderPro.flip();
return shaderPro;
}
private static int checkGLError(int location, String name){
if(location == -1){
System.out.println("Error: couldn't loacte " + name);
return 0;
}
return 1;
}
public static String getLogMessagePrograms(){
if((VPSupported && FPSupported)) return "Success";
if(VPSupported && !FPSupported) return "Error: Fragment Program is not supported";
return "Error: Fragment & Vertex Programs are not supported";
}
public static String getLogMessageShaders(){
if((VSSupported && FSSupported)) return "Success";
if(VSSupported && !FSSupported) return "Error: Fragment Shader is not supported";
return "Error: Fragment & Vertex Shaders are not supported";
}
}
So can all of this code be converted to C?
Thanks,
Chris
