From 5f551d6888fb64cfac15a80b1a0554467b3208ca Mon Sep 17 00:00:00 2001
From: InfiniteCoder <info@infinitecoder.org>
Date: Sat, 24 Feb 2024 00:21:17 +0300
Subject: [PATCH] Multiple Hitboxes

---
 src/content/ContentLoader.cpp  |  9 +++++++++
 src/frontend/WorldRenderer.cpp | 34 ++++++++++++++++++++++------------
 src/voxels/Block.h             |  1 +
 src/voxels/Chunks.cpp          | 15 ++++++++++-----
 4 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/src/content/ContentLoader.cpp b/src/content/ContentLoader.cpp
index 00a325d8..75629b57 100644
--- a/src/content/ContentLoader.cpp
+++ b/src/content/ContentLoader.cpp
@@ -151,6 +151,15 @@ void ContentLoader::loadBlock(Block& def, std::string name, fs::path file) {
         aabb.a = glm::vec3(boxarr->num(0), boxarr->num(1), boxarr->num(2));
         aabb.b = glm::vec3(boxarr->num(3), boxarr->num(4), boxarr->num(5));
         aabb.b += aabb.a;
+        def.hitboxExplicit = true;
+    } else if (def.modelBoxes.empty()) {
+        def.hitboxExplicit = true;
+    } else {
+        def.hitbox = def.modelBoxes[0];
+        for (const auto& box : def.modelBoxes) {
+            def.hitbox.a = glm::min(def.hitbox.a, box.a);
+            def.hitbox.b = glm::max(def.hitbox.b, box.b);
+        }
     }
 
     // block light emission [r, g, b] where r,g,b in range [0..15]
diff --git a/src/frontend/WorldRenderer.cpp b/src/frontend/WorldRenderer.cpp
index 2e25d6f4..4408c5eb 100644
--- a/src/frontend/WorldRenderer.cpp
+++ b/src/frontend/WorldRenderer.cpp
@@ -190,20 +190,30 @@ void WorldRenderer::draw(const GfxContext& pctx, Camera* camera, bool hudVisible
 			const vec3 pos = PlayerController::selectedBlockPosition;
 			const vec3 point = PlayerController::selectedPointPosition;
 			const vec3 norm = PlayerController::selectedBlockNormal;
-			AABB hitbox = block->hitbox;
+
+            std::vector<AABB> hitboxes;
+            if (!block->hitboxExplicit) {
+                hitboxes = block->modelBoxes;
+            } else {
+                hitboxes = { block->hitbox };
+            }
 			if (block->rotatable) {
-				auto states = PlayerController::selectedBlockStates;
-				block->rotations.variants[states].transform(hitbox);
+                auto states = PlayerController::selectedBlockStates;
+                for (auto& hitbox: hitboxes) {
+                    block->rotations.variants[states].transform(hitbox);
+                }
 			}
 
-			const vec3 center = pos + hitbox.center();
-			const vec3 size = hitbox.size();
-			linesShader->use();
-			linesShader->uniformMatrix("u_projview", camera->getProjView());
-			lineBatch->lineWidth(2.0f);
-			lineBatch->box(center, size + vec3(0.02), vec4(0.f, 0.f, 0.f, 0.5f));
-			if (level->player->debug)
-				lineBatch->line(point, point+norm*0.5f, vec4(1.0f, 0.0f, 1.0f, 1.0f));
+            linesShader->use();
+            linesShader->uniformMatrix("u_projview", camera->getProjView());
+            lineBatch->lineWidth(2.0f);
+            for (auto& hitbox: hitboxes) {
+                const vec3 center = pos + hitbox.center();
+                const vec3 size = hitbox.size();
+                lineBatch->box(center, size + vec3(0.02), vec4(0.f, 0.f, 0.f, 0.5f));
+                if (level->player->debug)
+                    lineBatch->line(point, point+norm*0.5f, vec4(1.0f, 0.0f, 1.0f, 1.0f));
+            }
 			lineBatch->render();
 		}
 		skybox->unbind();
@@ -289,4 +299,4 @@ void WorldRenderer::drawBorders(int sx, int sy, int sz, int ex, int ey, int ez)
 	lineBatch->render();
 }
 
-float WorldRenderer::fog = 0.0f;
\ No newline at end of file
+float WorldRenderer::fog = 0.0f;
diff --git a/src/voxels/Block.h b/src/voxels/Block.h
index e51fc3b4..da2f4d13 100644
--- a/src/voxels/Block.h
+++ b/src/voxels/Block.h
@@ -94,6 +94,7 @@ public:
     bool grounded = false;
     bool hidden = false;
 	AABB hitbox;
+    bool hitboxExplicit = false;
 	BlockRotProfile rotations;
     std::string pickingItem = name+BLOCK_ITEM_SUFFIX;
     std::string scriptName = name.substr(name.find(':')+1);
diff --git a/src/voxels/Chunks.cpp b/src/voxels/Chunks.cpp
index f29b59a0..fa0b46b1 100644
--- a/src/voxels/Chunks.cpp
+++ b/src/voxels/Chunks.cpp
@@ -15,6 +15,7 @@
 
 #include <math.h>
 #include <limits.h>
+#include <vector>
 
 Chunks::Chunks(int w, int d, 
 			   int ox, int oz, 
@@ -52,7 +53,7 @@ const AABB* Chunks::isObstacleAt(float x, float y, float z){
 	int ix = floor(x);
 	int iy = floor(y);
 	int iz = floor(z);
-	voxel* v = get(ix,iy,iz);
+	voxel* v = get(ix, iy, iz);
 	if (v == nullptr)
 		return &contentIds->getBlockDef(0)->hitbox;
 	const Block* def = contentIds->getBlockDef(v->id);
@@ -62,10 +63,14 @@ const AABB* Chunks::isObstacleAt(float x, float y, float z){
 							 : def->hitbox;
 		if (def->rt.solid) {
 			return &hitbox;
-		} else {
-			if (hitbox.contains({x - ix, y - iy, z - iz}))
-				return &hitbox;
-			return nullptr;
+		} else if (def->hitboxExplicit) {
+            if (hitbox.contains({x - ix, y - iy, z - iz}))
+                return &hitbox;
+        } else {
+            for (const auto& hitbox : def->modelBoxes) {
+			    if (hitbox.contains({x - ix, y - iy, z - iz}))
+                    return &hitbox;
+            }
 		}
 	}
 	return nullptr;