Drop-in palette lookup post-processing

Directly usable for devs

src/lwjgl/java/net/minestom/demo/largeframebuffers/Demo.java

@@ -16,6 +16,7 @@ import net.minestom.server.map.MapColors;
 import net.minestom.server.map.framebuffers.LargeDirectFramebuffer;
 import net.minestom.server.map.framebuffers.LargeGLFWFramebuffer;
 import net.minestom.server.map.framebuffers.LargeGraphics2DFramebuffer;
+import net.minestom.server.map.framebuffers.MapColorRenderer;
 import net.minestom.server.network.packet.server.play.MapDataPacket;
 import net.minestom.server.utils.Position;
 import net.minestom.server.utils.time.TimeUnit;
@@ -43,17 +44,16 @@ public class Demo {
         LargeGraphics2DFramebuffer graphics2DFramebuffer = new LargeGraphics2DFramebuffer(512, 512);
         LargeGLFWFramebuffer glfwFramebuffer = new LargeGLFWFramebuffer(512, 512);
 
-        glfwFramebuffer.useMapColors();
-
         glfwFramebuffer.changeRenderingThreadToCurrent();
         OpenGLRendering.init();
+        MapColorRenderer renderer = new MapColorRenderer(glfwFramebuffer, OpenGLRendering::render);
         glfwFramebuffer.unbindContextFromThread();
 
      //   renderingLoop(0, directFramebuffer, Demo::directRendering);
      //   renderingLoop(101, graphics2DFramebuffer, Demo::graphics2DRendering);
         renderingLoop(201, glfwFramebuffer, f -> {});
 
-        glfwFramebuffer.setupRenderLoop(15, TimeUnit.MILLISECOND, () -> OpenGLRendering.render(glfwFramebuffer));
+        glfwFramebuffer.setupRenderLoop(15, TimeUnit.MILLISECOND, renderer);
 
         for (int x = -2; x <= 2; x++) {
             for (int z = -2; z <= 2; z++) {

src/lwjgl/java/net/minestom/demo/largeframebuffers/OpenGLRendering.java

@@ -1,14 +1,14 @@
 package net.minestom.demo.largeframebuffers;
 
-import net.minestom.server.map.MapColors;
-import net.minestom.server.map.framebuffers.LargeGLFWFramebuffer;
 import org.joml.Matrix4f;
 import org.lwjgl.BufferUtils;
 import org.lwjgl.opengl.GLUtil;
 
 import javax.imageio.ImageIO;
 import java.awt.image.BufferedImage;
-import java.io.*;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
 import java.nio.ByteBuffer;
 import java.util.stream.Collectors;
 
@@ -64,13 +64,11 @@ public final  class OpenGLRendering {
     private static int projectionUniform;
     private static int viewUniform;
     private static int modelUniform;
-    private static int paletteTexture;
     private static int boxTexture;
 
     static void init() {
         GLUtil.setupDebugMessageCallback();
 
-        paletteTexture = loadTexture("palette");
         boxTexture = loadTexture("box");
 
         vbo = glGenBuffers();
@@ -81,15 +79,6 @@ public final  class OpenGLRendering {
         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
         glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices, GL_STATIC_DRAW);
 
-        glBindBuffer(GL_ARRAY_BUFFER, vbo);
-
-        glEnableVertexAttribArray(0);
-        glVertexAttribPointer(0, 3, GL_FLOAT, false, VERTEX_SIZE, 0); // position
-        glEnableVertexAttribArray(1);
-        glVertexAttribPointer(1, 2, GL_FLOAT, false, VERTEX_SIZE, 3*4); // color
-
-        glBindBuffer(GL_ARRAY_BUFFER, 0);
-
         // prepare matrices and shader
         renderShader = glCreateProgram();
         projectionMatrix = new Matrix4f().setPerspective((float) (Math.PI/4f), 1f, 0.001f, 100f);
@@ -107,8 +96,6 @@ public final  class OpenGLRendering {
         projectionUniform = glGetUniformLocation(renderShader, "projection");
         viewUniform = glGetUniformLocation(renderShader, "view");
         modelUniform = glGetUniformLocation(renderShader, "model");
-        int paletteSizeUniform = glGetUniformLocation(renderShader, "paletteSize");
-        int paletteUniform = glGetUniformLocation(renderShader, "palette");
         int boxUniform = glGetUniformLocation(renderShader, "box");
 
         glUseProgram(renderShader); {
@@ -116,9 +103,8 @@ public final  class OpenGLRendering {
             uploadMatrix(viewUniform, viewMatrix);
 
             glUniform1i(boxUniform, 0); // texture unit 0
-            glUniform1i(paletteUniform, 1); // texture unit 1
-            glUniform1f(paletteSizeUniform, 236);
         }
+        glUseProgram(0);
     }
 
     private static int loadTexture(String filename) {
@@ -166,7 +152,6 @@ public final  class OpenGLRendering {
     private static int createShader(String filename, int type) {
         int shader = glCreateShader(type);
         try(BufferedReader reader = new BufferedReader(new InputStreamReader(OpenGLRendering.class.getResourceAsStream(filename)))) {
-            StringBuffer buffer = new StringBuffer();
             String source = reader.lines().collect(Collectors.joining("\n"));
             glShaderSource(shader, source);
             glCompileShader(shader);
@@ -180,7 +165,7 @@ public final  class OpenGLRendering {
 
     private static int frame = 0;
 
-    static void render(LargeGLFWFramebuffer framebuffer) {
+    static void render() {
         if(frame % 100 == 0) {
             long time = System.currentTimeMillis();
             long dt = time-lastTime;
@@ -192,23 +177,24 @@ public final  class OpenGLRendering {
         frame++;
 
 
-        glClearColor(MapColors.COLOR_BLACK.multiply53()/255.0f, 0f, 0f, 1f);
+        glClearColor(0f, 0f, 0f, 1f);
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
         glEnable(GL_DEPTH_TEST);
 
         modelMatrix.rotateY((float) (Math.PI/60f));
 
-        // TODO: render texture
         glUseProgram(renderShader); {
-            glActiveTexture(GL_TEXTURE1);
-            glBindTexture(GL_TEXTURE_2D, paletteTexture);
-
             glActiveTexture(GL_TEXTURE0);
             glBindTexture(GL_TEXTURE_2D, boxTexture);
 
             uploadMatrix(modelUniform, modelMatrix);
             glBindBuffer(GL_ARRAY_BUFFER, vbo);
+            glEnableVertexAttribArray(0);
+            glVertexAttribPointer(0, 3, GL_FLOAT, false, VERTEX_SIZE, 0); // position
+            glEnableVertexAttribArray(1);
+            glVertexAttribPointer(1, 2, GL_FLOAT, false, VERTEX_SIZE, 3*4); // color
+
             glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
             glDrawElements(GL_TRIANGLES, indices.length, GL_UNSIGNED_INT, 0);
         }

src/lwjgl/java/net/minestom/server/map/framebuffers/MapColorRenderer.java

@@ -0,0 +1,257 @@
+package net.minestom.server.map.framebuffers;
+
+import org.lwjgl.BufferUtils;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.ByteBuffer;
+import java.util.stream.Collectors;
+
+import static org.lwjgl.opengl.GL30.*;
+
+/**
+ * Helper class designed to help OpenGL users to convert their RGB values to map colors inside a post processing pass
+ * with a shader provided by Minestom.
+ *
+ * When rendering to a {@link GLFWFramebuffer} or a {@link LargeGLFWFramebuffer}, wrap your rendering in a MapColorRenderer to render to the GLFW with map colors.
+ *
+ * {@link MapColorRenderer} sets up an OpenGL framebuffer with the size of the underlying framebuffer and renders to it.
+ * The initialization of the framebuffer is done in the constructor.
+ * Therefore, the constructor call should be done inside the thread linked to the OpenGL context. The context can
+ * be moved through {@link GLFWCapableBuffer#changeRenderingThreadToCurrent()} and {@link GLFWCapableBuffer#unbindContextFromThread()}
+ *
+ * <hr/>
+ * Resources created in constructor are:
+ * <li>
+ *     <ul>Framebuffer</ul>
+ *     <ul>Color texture (if default fbo initialization chosen)</ul>
+ *     <ul>Depth24 Stencil8 render buffer (if default fbo initialization chosen)</ul>
+ *     <ul>Post processing shader program</ul>
+ *     <ul>Palette texture</ul>
+ *     <ul>Screen quad VAO</ul>
+ *     <ul>Screen quad index buffer</ul>
+ * </li>
+ *
+ * The constructor also puts the given buffer in map color mode.
+ */
+public class MapColorRenderer implements Runnable {
+
+    private final int fboID;
+    private final GLFWCapableBuffer framebuffer;
+    private final Runnable renderCode;
+    private final int colorTextureID;
+    private final int width;
+    private final int height;
+    private final int renderShader;
+    private final int screenQuadIndices;
+    private int paletteTexture;
+    private float paletteSize;
+    private final int screenQuadVAO;
+
+    public MapColorRenderer(GLFWCapableBuffer framebuffer, Runnable renderCode) {
+        this(framebuffer, renderCode, MapColorRenderer.defaultFramebuffer(framebuffer.width(), framebuffer.height()));
+    }
+
+    public MapColorRenderer(GLFWCapableBuffer framebuffer, Runnable renderCode, FboInitialization fboInitialization) {
+        this.framebuffer = framebuffer;
+        this.framebuffer.useMapColors();
+
+        this.renderCode = renderCode;
+        this.width = framebuffer.width();
+        this.height = framebuffer.height();
+
+        this.fboID = glGenFramebuffers();
+        glBindFramebuffer(GL_FRAMEBUFFER, fboID);
+        this.colorTextureID = fboInitialization.initFbo(fboID);
+
+        if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
+            throw new RuntimeException("Framebuffer is not complete!");
+        }
+        glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+        // create post-process shader
+        this.renderShader = glCreateProgram();
+        int vertexShader = createShader("/shaders/mapcolorconvert.vertex.glsl", GL_VERTEX_SHADER);
+        int fragmentShader = createShader("/shaders/mapcolorconvert.fragment.glsl", GL_FRAGMENT_SHADER);
+        glAttachShader(renderShader, vertexShader);
+        glAttachShader(renderShader, fragmentShader);
+        glLinkProgram(renderShader);
+        if(glGetProgrami(renderShader, GL_LINK_STATUS) == 0) {
+            throw new RuntimeException("Link error: "+glGetProgramInfoLog(renderShader));
+        }
+
+        loadPalette("palette");
+
+        // create screen quad VAO
+        screenQuadVAO = glGenBuffers();
+        glBindBuffer(GL_ARRAY_BUFFER, screenQuadVAO);
+        glBufferData(GL_ARRAY_BUFFER, new float[] {
+                -1f, -1f,
+                1f, -1f,
+                1f, 1f,
+                -1f, 1f
+        }, GL_STATIC_DRAW);
+        glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+        screenQuadIndices = glGenBuffers();
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, screenQuadIndices);
+        glBufferData(GL_ELEMENT_ARRAY_BUFFER, new int[] {0,1,2, 2,3,0}, GL_STATIC_DRAW);
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+
+        int paletteSizeUniform = glGetUniformLocation(renderShader, "paletteSize");
+        int paletteUniform = glGetUniformLocation(renderShader, "palette");
+        int frameUniform = glGetUniformLocation(renderShader, "frame");
+
+        glUseProgram(renderShader); {
+            glUniform1i(frameUniform, 0); // texture unit 0
+            glUniform1i(paletteUniform, 1); // texture unit 1
+            glUniform1f(paletteSizeUniform, paletteSize);
+        }
+        glUseProgram(0);
+    }
+
+    private static FboInitialization defaultFramebuffer(int width, int height) {
+        return fboId -> defaultFramebufferInit(fboId, width, height);
+    }
+
+    private static int defaultFramebufferInit(int fbo, int width, int height) {
+        // color
+        int colorTexture = glGenTextures();
+        glBindTexture(GL_TEXTURE_2D, colorTexture);
+
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0L);
+
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+        // attach to framebuffer
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colorTexture, 0);
+        glBindTexture(GL_TEXTURE_2D, 0);
+
+        // depth
+        int depthStencilBuffer = glGenRenderbuffers();
+        glBindRenderbuffer(GL_RENDERBUFFER, depthStencilBuffer);
+        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, width, height);
+        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, depthStencilBuffer);
+        glBindRenderbuffer(GL_RENDERBUFFER, 0);
+        return colorTexture;
+    }
+
+    @Override
+    public void run() {
+        glViewport(0, 0, width, height);
+        // run user code inside of framebuffer
+        glBindFramebuffer(GL_FRAMEBUFFER, fboID);
+        renderCode.run();
+
+        // run post processing to display on screen
+        glBindFramebuffer(GL_FRAMEBUFFER, 0);
+        glClearColor(0f, 0f, 0f, 1f); // 0 on RED channel makes maps use NONE
+        glClear(GL_COLOR_BUFFER_BIT);
+        glDisable(GL_DEPTH_TEST);
+
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, colorTextureID);
+
+        glActiveTexture(GL_TEXTURE1);
+        glBindTexture(GL_TEXTURE_2D, paletteTexture);
+
+        glUseProgram(renderShader); {
+            // render post processing quad
+            glBindBuffer(GL_ARRAY_BUFFER, screenQuadVAO);
+            glEnableVertexAttribArray(0);
+            glVertexAttribPointer(0, 2, GL_FLOAT, false, 2*4, 0); // position
+
+            glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, screenQuadIndices);
+            glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
+        };
+
+        glUseProgram(0);
+        glBindBuffer(GL_ARRAY_BUFFER, 0);
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+
+        glActiveTexture(GL_TEXTURE1);
+        glBindTexture(GL_TEXTURE_2D, 0);
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, 0);
+    }
+
+    /**
+     * Frees OpenGL resources used by this renderer.
+     * You should NOT render with this renderer after this call.
+     */
+    public void cleanupResources() {
+        glDeleteFramebuffers(fboID);
+        glDeleteProgram(renderShader);
+        glDeleteTextures(paletteTexture);
+        // TODO: more cleanup
+    }
+
+    private void loadPalette(String filename) {
+        int tex = glGenTextures();
+        glBindTexture(GL_TEXTURE_2D, tex);
+        BufferedImage image;
+        try {
+            image = ImageIO.read(MapColorRenderer.class.getResourceAsStream("/textures/"+filename+".png"));
+        } catch (IOException e) {
+            e.printStackTrace();
+            throw new RuntimeException("Missing image "+filename, e);
+        }
+        ByteBuffer pixels = BufferUtils.createByteBuffer(image.getWidth()*image.getHeight()*4);
+        for (int y = 0; y < image.getHeight(); y++) {
+            for (int x = 0; x < image.getWidth(); x++) {
+                int rgb = image.getRGB(x, y);
+                int alpha = (rgb >> 24) & 0xFF;
+                int red = (rgb >> 16) & 0xFF;
+                int green = (rgb >> 8) & 0xFF;
+                int blue = rgb & 0xFF;
+                pixels.put((byte) red);
+                pixels.put((byte) green);
+                pixels.put((byte) blue);
+                pixels.put((byte) alpha);
+            }
+        }
+        pixels.flip();
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, image.getWidth(), image.getHeight(), 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+
+        // closest neighbor required here, as pixels can have very different rgb values, and interpolation will break palette lookup
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+        glBindTexture(GL_TEXTURE_2D, 0);
+
+        this.paletteTexture = tex;
+        this.paletteSize = image.getWidth();
+    }
+
+    private static int createShader(String filename, int type) {
+        int shader = glCreateShader(type);
+        try(BufferedReader reader = new BufferedReader(new InputStreamReader(MapColorRenderer.class.getResourceAsStream(filename)))) {
+            String source = reader.lines().collect(Collectors.joining("\n"));
+            glShaderSource(shader, source);
+            glCompileShader(shader);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return shader;
+    }
+
+    @FunctionalInterface
+    public interface FboInitialization {
+
+        /**
+         * Initializes the given framebuffer
+         * @param fboId
+         * @return the texture ID of the color texture, used for post processing.
+         */
+        int initFbo(int fboId);
+    }
+
+}
+
+
+

src/lwjgl/resources/shaders/fragment.glsl

@@ -5,29 +5,8 @@ in vec2 uv;
 out vec4 fragColor;
 
 uniform sampler2D box;
-uniform sampler2D palette;
-uniform float paletteSize;
 
 void main() {
     vec3 vertexColor = texture(box, uv).rgb;
-
-
-    // render in map colors
-    int closest = 0;
-    uint closestDistance = uint(2147483647);
-    for(int i = 4; i < paletteSize; i++) {
-        vec3 mapColor = texture(palette, vec2((i+0.5f)/paletteSize, 0.0)).rgb;
-        int dr = int((mapColor.r - vertexColor.r)*255);
-        int dg = int((mapColor.g - vertexColor.g)*255);
-        int db = int((mapColor.b - vertexColor.b)*255);
-
-        uint d = uint(dr*dr)+uint(dg*dg)+uint(db*db);
-        if(d < closestDistance) {
-            closestDistance = d;
-            closest = i;
-        }
-    }
-
-    fragColor = vec4(closest/255.0, closest/255.0, closest/255.0, 1.0);
-    //fragColor = vec4(vertexColor, 1.0);
+    fragColor = vec4(vertexColor, 1.0);
 }

src/lwjgl/resources/shaders/mapcolorconvert.fragment.glsl

@@ -0,0 +1,30 @@
+#version 330
+
+in vec2 fragCoords;
+out vec4 fragColor;
+
+uniform sampler2D frame;
+uniform sampler2D palette;
+uniform float paletteSize;
+
+void main() {
+    vec3 fragmentColor = texture(frame, fragCoords).rgb;
+
+    // render in map colors
+    int closest = 0;
+    uint closestDistance = uint(2147483647);
+    for(int i = 4; i < paletteSize; i++) {
+        vec3 mapColor = texture(palette, vec2((i+0.5f)/paletteSize, 0.0)).rgb;
+        int dr = int((mapColor.r - fragmentColor.r)*255);
+        int dg = int((mapColor.g - fragmentColor.g)*255);
+        int db = int((mapColor.b - fragmentColor.b)*255);
+
+        uint d = uint(dr*dr)+uint(dg*dg)+uint(db*db);
+        if(d < closestDistance) {
+            closestDistance = d;
+            closest = i;
+        }
+    }
+
+    fragColor = vec4(closest/255.0, closest/255.0, closest/255.0, 1.0);
+}

src/lwjgl/resources/shaders/mapcolorconvert.vertex.glsl

@@ -0,0 +1,10 @@
+#version 330
+
+layout(location = 0) in vec2 pos;
+
+out vec2 fragCoords;
+
+void main() {
+    fragCoords = (pos+vec2(1.0))/2.0;
+    gl_Position = vec4(pos, 0.0, 1.0);
+}