Более аккуратное восстановление состояния

src/client/java/su/divan2000/veila/client/gl/FullscreenQuad.java

@@ -39,6 +39,7 @@ public final class FullscreenQuad {
         vbo = GL15.glGenBuffers();
 
         int previous = glGetInteger(GL_VERTEX_ARRAY_BINDING);
+        int previousArrayBuffer = GL11.glGetInteger(GL15.GL_ARRAY_BUFFER_BINDING);
 
         GL30.glBindVertexArray(vao);
 
@@ -56,6 +57,7 @@ public final class FullscreenQuad {
         );
 
         GL30.glBindVertexArray(previous);
+        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, previousArrayBuffer);
     }
 
     public static void draw() {

src/client/java/su/divan2000/veila/client/render/PostProcessingManager.java

@@ -41,6 +41,10 @@ public class PostProcessingManager {
     private static final FloatBuffer projectionBuffer = BufferUtils.createFloatBuffer(16);
     private static final FloatBuffer inverseProjectionBuffer = BufferUtils.createFloatBuffer(16);
 
+    private static final int[] previousViewport = new int[4];
+    private static final int[] previousTexture2D = new int[5];
+    private static final int[] previousTexture3D = new int[5];
+
     /*
      * Uniform locations - Raymarch Program
      */
@@ -171,11 +175,15 @@ public class PostProcessingManager {
         scaledWidth = (int)(width * scale);
         scaledHeight = (int)(height * scale);
 
+        int previousFramebuffer = GL11.glGetInteger(GL30.GL_FRAMEBUFFER_BINDING);
+        int previousActiveTexture = GL11.glGetInteger(GL13.GL_ACTIVE_TEXTURE);
+        GL13.glActiveTexture(GL13.GL_TEXTURE0);
+        int previousTexture0 = GL11.glGetInteger(GL11.GL_TEXTURE_BINDING_2D);
+
         scaledFBO = GL30.glGenFramebuffers();
         GL30.glBindFramebuffer(GL30.GL_FRAMEBUFFER, scaledFBO);
 
         scaledTexture = GL11.glGenTextures();
-        GL13.glActiveTexture(GL13.GL_TEXTURE0);
         GL11.glBindTexture(GL11.GL_TEXTURE_2D, scaledTexture);
         GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL30.GL_RGBA16F, scaledWidth, scaledHeight, 0, GL11.GL_RGBA, GL11.GL_FLOAT, 0);
         GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR);
@@ -196,7 +204,9 @@ public class PostProcessingManager {
 
         GL30.glFramebufferTexture2D(GL30.GL_FRAMEBUFFER, GL30.GL_COLOR_ATTACHMENT1, GL11.GL_TEXTURE_2D, scaledDepthTexture, 0);
 
-        GL30.glBindFramebuffer(GL30.GL_FRAMEBUFFER, 0);
+        GL11.glBindTexture(GL11.GL_TEXTURE_2D, previousTexture0);
+        GL13.glActiveTexture(previousActiveTexture);
+        GL30.glBindFramebuffer(GL30.GL_FRAMEBUFFER, previousFramebuffer);
     }
 
     public static void render(float tickDelta) {
@@ -208,6 +218,21 @@ public class PostProcessingManager {
         if (client.world == null)
             return;
 
+        int previousProgram = GL11.glGetInteger(GL20.GL_CURRENT_PROGRAM);
+        int previousActiveTexture = GL11.glGetInteger(GL13.GL_ACTIVE_TEXTURE);
+        int previousDrawFramebuffer = GL11.glGetInteger(GL30.GL_DRAW_FRAMEBUFFER_BINDING);
+        int previousReadFramebuffer = GL11.glGetInteger(GL30.GL_READ_FRAMEBUFFER_BINDING);
+        int previousDrawBuffer = GL11.glGetInteger(GL11.GL_DRAW_BUFFER);
+        GL11.glGetIntegerv(GL11.GL_VIEWPORT, previousViewport);
+
+        for (int unit = 0; unit <= 4; unit++) {
+            GL13.glActiveTexture(GL13.GL_TEXTURE0 + unit);
+            previousTexture2D[unit] = GL11.glGetInteger(GL11.GL_TEXTURE_BINDING_2D);
+            previousTexture3D[unit] = GL11.glGetInteger(GL12.GL_TEXTURE_BINDING_3D);
+        }
+        GL13.glActiveTexture(previousActiveTexture);
+
+        try {
             Framebuffer framebuffer = client.getFramebuffer();
 
             int width = framebuffer.textureWidth;
@@ -227,6 +252,7 @@ public class PostProcessingManager {
 
             DepthCopy.init(width, height);
             DepthCopy.copy(width, height);
+            updateProjectionMatrices();
 
             renderDepthDownsample(width, height);
 
@@ -237,7 +263,19 @@ public class PostProcessingManager {
             renderComposite(framebuffer, width, height);
 
             GL30.glBindFramebuffer(GL30.GL_READ_FRAMEBUFFER, 0);
-        GL13.glActiveTexture(GL13.GL_TEXTURE0);
+        } finally {
+            for (int unit = 4; unit >= 0; unit--) {
+                GL13.glActiveTexture(GL13.GL_TEXTURE0 + unit);
+                GL11.glBindTexture(GL11.GL_TEXTURE_2D, previousTexture2D[unit]);
+                GL11.glBindTexture(GL12.GL_TEXTURE_3D, previousTexture3D[unit]);
+            }
+            GL13.glActiveTexture(previousActiveTexture);
+            GL20.glUseProgram(previousProgram);
+            GL30.glBindFramebuffer(GL30.GL_DRAW_FRAMEBUFFER, previousDrawFramebuffer);
+            GL30.glBindFramebuffer(GL30.GL_READ_FRAMEBUFFER, previousReadFramebuffer);
+            GL11.glDrawBuffer(previousDrawBuffer);
+            GL11.glViewport(previousViewport[0], previousViewport[1], previousViewport[2], previousViewport[3]);
+        }
     }
 
     private static void renderDepthDownsample(int width, int height) {
@@ -259,7 +297,6 @@ public class PostProcessingManager {
 
         FullscreenQuad.draw();
 
-        GL11.glBindTexture(GL11.GL_TEXTURE_2D, 0);
         depthDownsampleProgram.unbind();
     }
 
@@ -306,7 +343,6 @@ public class PostProcessingManager {
                 FogSystem.ringChunkOffsetZ() * FogWorldVolume.CHUNK_SIZE);
 
         // Матрицы
-        updateProjectionMatrices();
         GL20.glUniformMatrix4fv(rm_projectionLocation, false, projectionBuffer);
         GL20.glUniformMatrix4fv(rm_inverseProjectionLocation, false, inverseProjectionBuffer);
         GL20.glUniformMatrix4fv(rm_viewLocation, false, viewBuffer);
@@ -372,7 +408,6 @@ public class PostProcessingManager {
         GL20.glUniform1i(comp_scaledDepthSamplerLocation, 3);
 
         // Матрицы для линеаризации depth
-        updateProjectionMatrices();
         GL20.glUniformMatrix4fv(comp_inverseProjectionLocation, false, inverseProjectionBuffer);
 
         // Screen size
@@ -382,14 +417,7 @@ public class PostProcessingManager {
         FullscreenQuad.draw();
 
         // Очистка
-        GL13.glActiveTexture(GL13.GL_TEXTURE3);
+        // restore state once in render() finalizer
-        GL11.glBindTexture(GL11.GL_TEXTURE_2D, 0);
-        GL13.glActiveTexture(GL13.GL_TEXTURE2);
-        GL11.glBindTexture(GL11.GL_TEXTURE_2D, 0);
-        GL13.glActiveTexture(GL13.GL_TEXTURE1);
-        GL11.glBindTexture(GL11.GL_TEXTURE_2D, 0);
-        GL13.glActiveTexture(GL13.GL_TEXTURE0);
-        GL11.glBindTexture(GL11.GL_TEXTURE_2D, 0);
 
         compositeProgram.unbind();
     }