nice try, but it crashes the gpu AND I get <1 fps :(

assets/raytracelight.frag

@@ -61,12 +61,18 @@ vec2[TRAVERSE_SIZE] traceRay(int arraySize, vec2 from, vec2 to) {
 
 void main() {
 
+    // this code will produce y-flipped image. It's your job to flip it again (e.g. using y-flipped fullscreen quad)
+
+    // Nice try, but it kills GPU :(
+    // reason: looks like traceRayCount() returns value greater than TRAVERSE_SIZE.
+    //         even if I make traceRayCount() to return constant 3, I get less than 1 fps on GTX 970.
+
     vec4 outColor = vec4(0.0,0.0,0.0,0.0);
 
     // 1. pick a light source
     for (int y = 0; y < int(outSize.y); y++) {
         for (int x = 0; x < int(outSize.x); x++) {
-            vec2 from = vec2(x, y);
+            vec2 from = vec2(x + 0.5, y + 0.5); // +0.5 is used because gl_FragCoord does
             vec2 to = gl_FragCoord.xy;
             vec2 delta = to - from;
             int traceCount = traceRayCount(delta);
@@ -94,10 +100,9 @@ void main() {
     }
 
     gl_FragColor = outColor * multiplier;
-    gl_FragColor = vec4(0,1,0,1);
+    //gl_FragColor = vec4(0,1,0,1);
 
-    gl_FragColor = vec4(texture2D(lights, gl_FragCoord.xy / outSize)) * multiplier;
+    //gl_FragColor = sampleFrom(lights, gl_FragCoord.xy) * multiplier;
 
-    // FIXME (gl_FragCoord / outSize) != v_texCoords
 
 }

src/net/torvald/terrarum/AppLoader.java

@@ -496,7 +496,7 @@ public class AppLoader implements ApplicationListener {
         logoBatch.setProjectionMatrix(camera.combined);
     }
 
-    private void updateFullscreenQuad(int WIDTH, int HEIGHT) {
+    private void updateFullscreenQuad(int WIDTH, int HEIGHT) { // NOT y-flipped quads!
         fullscreenQuad.setVertices(new float[]{
                 0f, 0f, 0f, 1f, 1f, 1f, 1f, 0f, 1f,
                 WIDTH, 0f, 0f, 1f, 1f, 1f, 1f, 1f, 1f,
@@ -650,16 +650,19 @@ public class AppLoader implements ApplicationListener {
      * Return config from config set. If the config does not exist, default value will be returned.
      * @param key
      * *
-     * @return Config from config set or default config if it does not exist.
+     * @return Config from config set or default config if it does not exist. If the default value is undefined, will return false.
-     * *
-     * @throws NullPointerException if the specified config simply does not exist.
      */
     public static boolean getConfigBoolean(String key) {
-        Object cfg = getConfigMaster(key);
+        try {
-        if (cfg instanceof JsonPrimitive)
+            Object cfg = getConfigMaster(key);
-        return ((JsonPrimitive) cfg).getAsBoolean();
+            if (cfg instanceof JsonPrimitive)
-        else
+                return ((JsonPrimitive) cfg).getAsBoolean();
-        return ((boolean) cfg);
+            else
+                return ((boolean) cfg);
+        }
+        catch (NullPointerException keyNotFound) {
+            return false;
+        }
     }
 
     public static int[] getConfigIntArray(String key) {

src/net/torvald/terrarum/DefaultConfig.kt

@@ -24,7 +24,6 @@ object DefaultConfig {
         jsonObject.addProperty("notificationshowuptime", 6500)
         jsonObject.addProperty("multithread", true) // experimental!
         jsonObject.addProperty("multithreadedlight", false) // experimental!
-        jsonObject.addProperty("gpulightcalc", true) // experimental!
 
 
 

src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt

@@ -105,10 +105,6 @@ object LightmapRenderer {
 
         if (SHADER_LIGHTING) {
             lightCalcShader = AppLoader.loadShader("assets/4096.vert", "assets/raytracelight.frag")
-            lightCalcShader.setUniformf("outSize", LIGHTMAP_WIDTH.toFloat(), LIGHTMAP_HEIGHT.toFloat())
-            lightCalcShader.setUniformi("shades", SHADEMAP_UNIT)
-            lightCalcShader.setUniformi("lights", LIGHTMAP_UNIT)
-            lightCalcShader.setUniformi("u_texture", 0)
 
             texturedLightMap = FrameBuffer(Pixmap.Format.RGBA8888, LIGHTMAP_WIDTH, LIGHTMAP_HEIGHT, false)
             //texturedLightMap = Texture(LIGHTMAP_WIDTH, LIGHTMAP_HEIGHT, Pixmap.Format.RGBA8888)
@@ -133,11 +129,11 @@ object LightmapRenderer {
                     VertexAttribute.ColorUnpacked(),
                     VertexAttribute.TexCoords(0)
             )
-            texturedLightQuad.setVertices(floatArrayOf(
+            texturedLightQuad.setVertices(floatArrayOf( // y-flipped quads!
-                    0f, 0f, 0f, 1f, 1f, 1f, 1f, 0f, 1f,
+                    0f, 0f, 0f, 1f, 1f, 1f, 1f, 0f, 0f,
-                    LIGHTMAP_WIDTH.toFloat(), 0f, 0f, 1f, 1f, 1f, 1f, 1f, 1f,
+                    LIGHTMAP_WIDTH.toFloat(), 0f, 0f, 1f, 1f, 1f, 1f, 1f, 0f,
-                    LIGHTMAP_WIDTH.toFloat(), LIGHTMAP_HEIGHT.toFloat(), 0f, 1f, 1f, 1f, 1f, 1f, 0f,
+                    LIGHTMAP_WIDTH.toFloat(), LIGHTMAP_HEIGHT.toFloat(), 0f, 1f, 1f, 1f, 1f, 1f, 1f,
-                    0f, LIGHTMAP_HEIGHT.toFloat(), 0f, 1f, 1f, 1f, 1f, 0f, 0f))
+                    0f, LIGHTMAP_HEIGHT.toFloat(), 0f, 1f, 1f, 1f, 1f, 0f, 1f))
             texturedLightQuad.setIndices(shortArrayOf(0, 1, 2, 2, 3, 0))
 
             texturedLightCamera = OrthographicCamera(LIGHTMAP_WIDTH.toFloat(), LIGHTMAP_HEIGHT.toFloat())
@@ -433,7 +429,11 @@ object LightmapRenderer {
                     texturedLightSources.bind(LIGHTMAP_UNIT)
 
                     lightCalcShader.begin()
+                    // it seems that every time shader ends, uniforms reset themselves.
                     lightCalcShader.setUniformMatrix("u_projTrans", texturedLightCamera.combined)
+                    lightCalcShader.setUniformf("outSize", LIGHTMAP_WIDTH.toFloat(), LIGHTMAP_HEIGHT.toFloat())
+                    lightCalcShader.setUniformi("shades", SHADEMAP_UNIT)
+                    lightCalcShader.setUniformi("lights", LIGHTMAP_UNIT)
                     texturedLightQuad.render(lightCalcShader, GL20.GL_TRIANGLES)
                     lightCalcShader.end()
                 }