Basic ShaderProgram util class

src/main/java/com/gtnewhorizon/gtnhlib/GTNHLib.java

@@ -18,7 +18,7 @@ public class GTNHLib {
     public static final String MODID = "gtnhlib";
     public static final String MODNAME = "GTNH Lib";
     public static final String GROUPNAME = "com.gtnewhorizon.gtnhlib";
-    private static final Logger LOG = LogManager.getLogger(GTNHLib.MODID);
+    public static final Logger LOG = LogManager.getLogger(GTNHLib.MODID);
 
     @SidedProxy(clientSide = GTNHLib.GROUPNAME + ".ClientProxy", serverSide = GTNHLib.GROUPNAME + ".CommonProxy")
     public static CommonProxy proxy;

src/main/java/com/gtnewhorizon/gtnhlib/client/renderer/shader/ShaderProgram.java

@@ -0,0 +1,159 @@
+package com.gtnewhorizon.gtnhlib.client.renderer.shader;
+
+import java.io.BufferedReader;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.OpenGlHelper;
+import net.minecraft.util.ResourceLocation;
+
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL20;
+
+import com.gtnewhorizon.gtnhlib.GTNHLib;
+
+@SuppressWarnings("unused")
+public class ShaderProgram {
+
+    final private int program;
+
+    public ShaderProgram(String domain, String vertShaderFilename, String fragShaderFilename) {
+        int program;
+        try {
+            program = createProgram(domain, vertShaderFilename, fragShaderFilename);
+        } catch (Exception e) {
+            GTNHLib.LOG.error("Could not initialize shader program!", e);
+            program = 0;
+        }
+        this.program = program;
+    }
+
+    private static String getProgramLogInfo(int obj) {
+        return GL20.glGetProgramInfoLog(obj, GL20.glGetProgrami(obj, GL20.GL_INFO_LOG_LENGTH));
+    }
+
+    private static String getShaderLogInfo(int obj) {
+        return GL20.glGetShaderInfoLog(obj, GL20.glGetShaderi(obj, GL20.GL_INFO_LOG_LENGTH));
+    }
+
+    private static int createProgram(String domain, String vertShaderFilename, String fragShaderFilename) {
+        if (!OpenGlHelper.shadersSupported) {
+            return 0;
+        }
+
+        final int program = GL20.glCreateProgram();
+
+        final int vertShader = loadAndCompileShader(program, domain, vertShaderFilename, GL20.GL_VERTEX_SHADER);
+        final int fragShader = loadAndCompileShader(program, domain, fragShaderFilename, GL20.GL_FRAGMENT_SHADER);
+
+        if (vertShader != 0) GL20.glAttachShader(program, vertShader);
+        if (fragShader != 0) GL20.glAttachShader(program, fragShader);
+
+        GL20.glLinkProgram(program);
+
+        if (GL20.glGetProgrami(program, GL20.GL_LINK_STATUS) == GL11.GL_FALSE) {
+            GTNHLib.LOG.error("Could not link shader: {}", getProgramLogInfo(program));
+            GL20.glDeleteProgram(program);
+            return 0;
+        }
+
+        GL20.glValidateProgram(program);
+
+        if (GL20.glGetProgrami(program, GL20.GL_VALIDATE_STATUS) == GL11.GL_FALSE) {
+            GTNHLib.LOG.error("Could not validate shader: {}", getProgramLogInfo(program));
+            GL20.glDeleteProgram(program);
+            return 0;
+        }
+        return program;
+    }
+
+    private static int loadAndCompileShader(int program, String domain, String filename, int shaderType) {
+        if (filename == null) {
+            return 0;
+        }
+
+        final int shader = GL20.glCreateShader(shaderType);
+
+        if (shader == 0) {
+            GTNHLib.LOG.error(
+                    "Could not create shader of type {} from {}: {}",
+                    shaderType,
+                    filename,
+                    getProgramLogInfo(program));
+            return 0;
+        }
+
+        final String code = loadFile(new ResourceLocation(domain, filename));
+        if (code == null) {
+            GL20.glDeleteShader(shader);
+            return 0;
+        }
+
+        GL20.glShaderSource(shader, code);
+        GL20.glCompileShader(shader);
+
+        if (GL20.glGetShaderi(shader, GL20.GL_COMPILE_STATUS) == GL11.GL_FALSE) {
+            GTNHLib.LOG.error("Could not compile shader {}: {}", filename, getShaderLogInfo(shader));
+            GL20.glDeleteShader(shader);
+            return 0;
+        }
+
+        return shader;
+    }
+
+    private static String loadFile(ResourceLocation resourceLocation) {
+        try {
+            final StringBuilder code = new StringBuilder();
+            final InputStream inputStream = Minecraft.getMinecraft().getResourceManager().getResource(resourceLocation)
+                    .getInputStream();
+            final BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
+
+            String line;
+            while ((line = reader.readLine()) != null) {
+                code.append(line);
+                code.append('\n');
+            }
+            reader.close();
+
+            return code.toString();
+        } catch (Exception e) {
+            GTNHLib.LOG.error("Could not load shader file!", e);
+        }
+
+        return null;
+    }
+
+    public int getProgram() {
+        return this.program;
+    }
+
+    public void use() {
+        GL20.glUseProgram(this.program);
+    }
+
+    public static void clear() {
+        GL20.glUseProgram(0);
+    }
+
+    public int getUniformLocation(String name) {
+        final int index = GL20.glGetUniformLocation(this.program, name);
+
+        if (index < 0) {
+            throw new NullPointerException("No uniform exists with name: " + name);
+        }
+
+        return index;
+    }
+
+    public int getAttribLocation(String name) {
+        final int index = GL20.glGetAttribLocation(this.program, name);
+
+        if (index < 0) {
+            throw new NullPointerException("No attribute exists with name: " + name);
+        }
+
+        return index;
+    }
+
+}