Occlusion Checking

docs/CHANGELOG.md

@@ -52,6 +52,7 @@
     * `Increase Render Chunk Size` (Enabled By Default)
     * `Proper Entity Shading` (Enabled By Default)
     * `Fix Sugar Position In Hand` (Enabled By Default)
+    * `Chunk OpenGL Occlusion Checking` (Disabled By Default)
   * Existing Functionality (All Enabled By Default)
     * `Fix Screen Rendering When Hiding HUD`
     * `Sanitize Usernames`

launcher/src/client/available-feature-flags

@@ -112,4 +112,5 @@ TRUE Render Entity Shadows
 TRUE Render Vignette
 TRUE Increase Render Chunk Size
 TRUE Proper Entity Shading
-TRUE Fix Sugar Position In Hand
+TRUE Fix Sugar Position In Hand
+FALSE Chunk OpenGL Occlusion Checking

mods/src/misc/graphics.cpp

@@ -501,6 +501,63 @@ static int safe_log2(const int x) {
     return z;
 }
 
+// Occlusion Checking
+static int num_occlusion_ids;
+static GLuint *occlusion_ids;
+static LevelRenderer *LevelRenderer_injection(LevelRenderer_constructor_t original, LevelRenderer *self, Minecraft *minecraft) {
+    // Call Original Method
+    original(self, minecraft);
+    // Setup
+    self->occlusion_check = true;
+    num_occlusion_ids = self->num_buffers / 3;
+    occlusion_ids = new GLuint[num_occlusion_ids];
+    media_glGenQueries(num_occlusion_ids, occlusion_ids);
+    return self;
+}
+static void LevelRenderer_allChanged_Chunk_setDirty_injection(Chunk *self) {
+    self->occlusion_id = int(occlusion_ids[self->id]);
+    // Call Original Method
+    self->setDirty();
+}
+static void check_query_result(Chunk *chunk) {
+    if (chunk->occlusion_querying) {
+        GLuint val;
+        media_glGetQueryObjectuiv(chunk->occlusion_id, GL_QUERY_RESULT_AVAILABLE, &val);
+        if (val != 0) {
+            chunk->occlusion_querying = false;
+            media_glGetQueryObjectuiv(chunk->occlusion_id, GL_QUERY_RESULT, &val);
+            chunk->occlusion_visible = val != 0;
+        }
+    }
+}
+static int LevelRenderer_render_LevelRenderer_renderChunks_injection(LevelRenderer *self, const int start, const int end, const int a, const float b) {
+    for (int i = start; i < end; i++) {
+        Chunk *chunk = self->chunks[i];
+        check_query_result(chunk);
+        chunk->occlusion_visible = true;
+    }
+    // Call Original Method
+    return self->renderChunks(start, end, a, b);
+}
+static bool LevelRenderer_render_Chunk_isEmpty_injection(Chunk *self) {
+    check_query_result(self);
+    // Call Original Method
+    return self->isEmpty();
+}
+static void Chunk_renderBB_injection(__attribute__((unused)) Chunk_renderBB_t original, Chunk *self) {
+    media_glBeginQuery(GL_SAMPLES_PASSED, self->occlusion_id);
+    AABB aabb = {
+        .x1 = self->aabb.x1 - float(self->x),
+        .y1 = self->aabb.y1 - float(self->y),
+        .z1 = self->aabb.z1 - float(self->z),
+        .x2 = self->aabb.x2 - float(self->x),
+        .y2 = self->aabb.y2 - float(self->y),
+        .z2 = self->aabb.z2 - float(self->z)
+    };
+    EntityRenderer::renderFlat(aabb);
+    media_glEndQuery(GL_SAMPLES_PASSED);
+}
+
 // Init
 void _init_misc_graphics() {
     // Disable V-Sync
@@ -651,6 +708,15 @@ void _init_misc_graphics() {
         patch((void *) 0x4f20c, render_chunk_patch_seven);
     }
 
+    // Occlusion Checking
+    if(feature_has("Chunk OpenGL Occlusion Checking", server_disabled)) {
+        overwrite_calls(LevelRenderer_constructor, LevelRenderer_injection);
+        overwrite_call((void *) 0x4fce4, (void *) LevelRenderer_allChanged_Chunk_setDirty_injection);
+        overwrite_call((void *) 0x4f8d4, (void *) LevelRenderer_render_LevelRenderer_renderChunks_injection);
+        overwrite_call((void *) 0x4f960, (void *) LevelRenderer_render_Chunk_isEmpty_injection);
+        overwrite_calls(Chunk_renderBB, Chunk_renderBB_injection);
+    }
+
     // Don't Render Game In Headless Mode
     if (reborn_is_headless()) {
         overwrite_calls(GameRenderer_render, nop<GameRenderer_render_t, GameRenderer *, float>);

mods/src/multidraw/glue.cpp

@@ -94,13 +94,13 @@ static void multidraw_renderSameAsLast(const LevelRenderer *self, const float b)
     media_glDisableClientState(GL_TEXTURE_COORD_ARRAY);
     media_glPopMatrix();
 }
-static int LevelRenderer_renderChunks_injection(__attribute__((unused)) LevelRenderer_renderChunks_t original, LevelRenderer *self, const int start, const int end, const int a, const float b) {
+static int LevelRenderer_renderChunks_injection(__attribute__((unused)) LevelRenderer_renderChunks_t original, const LevelRenderer *self, const int start, const int end, const int a, const float b) {
     // Batch
     multidraw_total = 0;
     for (int i = start; i < end; i++) {
         Chunk *chunk = self->chunks[i];
         // Check If Chunk Is Visible
-        if (!chunk->field_1c[a] && chunk->visible) {
+        if (!chunk->field_1c[a] && chunk->visible && (!self->occlusion_check || chunk->occlusion_visible)) {
             const RenderChunk *render_chunk = chunk->getRenderChunk(a);
             // Get Data Block
             const int chunk_id = int(render_chunk->buffer - MULTIDRAW_BASE);

symbols/src/entity/EntityRenderer.def

@@ -10,3 +10,4 @@ property float shadow_strength = 0x8;
 
 // Globals
 static-property EntityRenderDispatcher *entityRenderDispatcher = 0x137bc0;
+static-method void renderFlat(const AABB &aabb) = 0x627c8;

symbols/src/level/renderer/Chunk.def

@@ -3,7 +3,15 @@ property int y = 0x8;
 property int z = 0xc;
 property bool field_1c[3] = 0x1c;
 property bool visible = 0x4c;
+property bool occlusion_visible = 0x4d;
+property bool occlusion_querying = 0x4e;
+property int occlusion_id = 0x50;
+property AABB aabb = 0x30;
+property int id = 0x48;
 
 method float distanceToSqr(const Entity *entity) = 0x47ba0;
 method int getList(int a) = 0x47e48;
 method RenderChunk *getRenderChunk(int a) = 0x47e74;
+method void renderBB() = 0x47ed8;
+method void setDirty() = 0x47ef0;
+method bool isEmpty() = 0x47edc;

symbols/src/level/renderer/LevelRenderer.def

@@ -1,3 +1,7 @@
+vtable 0x107438;
+
+constructor (Minecraft *minecraft) = 0x4e5f8;
+
 method void tick() = 0x4da1c;
 method int render(Mob *mob, int param_1, float delta) = 0x4f710;
 method void render_AABB(const AABB &box) = 0x4d740;
@@ -10,4 +14,6 @@ method void renderEntities(Vec3 pos, void *unknown, float a) = 0x500ec;
 
 property Minecraft *minecraft = 0xb4;
 property RenderList render_list = 0x34;
-property Chunk **chunks = 0x98;
+property Chunk **chunks = 0x98;
+property bool occlusion_check = 0xb8;
+property int num_buffers = 0xd0;