AABB block hitboxes

src/content/Content.cpp

@@ -1,9 +1,11 @@
 #include "Content.h"
 
 #include <stdexcept>
+#include <glm/glm.hpp>
 
 #include "../voxels/Block.h"
 
+using glm::vec3;
 using std::vector;
 using std::string;
 using std::unordered_map;
@@ -21,6 +23,24 @@ Content* ContentBuilder::build() {
     for (const string& name : blockIds) {
         Block* def = blockDefs[name];
         def->id = blockDefsIndices.size();
+        def->rt.emissive = *((uint32_t*)def->emission);
+        
+        // build hitbox grid 3d for raycasts
+        const AABB& hitbox = def->hitbox;
+        for (uint gy = 0; gy < BLOCK_AABB_GRID; gy++) {
+            for (uint gz = 0; gz < BLOCK_AABB_GRID; gz++) {
+                for (uint gx = 0; gx < BLOCK_AABB_GRID; gx++) {
+                    float x = gx / float(BLOCK_AABB_GRID);
+                    float y = gy / float(BLOCK_AABB_GRID);
+                    float z = gz / float(BLOCK_AABB_GRID);
+                    bool flag = hitbox.inside({x, y, z});
+                    if (!flag)
+                        def->rt.solid = false;
+                    def->rt.hitboxGrid[gy][gz][gx] = flag;
+                }
+            }
+        }
+
         blockDefsIndices.push_back(def);
     }
     ContentIndices* indices = new ContentIndices(blockDefsIndices);

src/definitions.cpp

@@ -1,11 +1,15 @@
 #include "definitions.h"
 
+#include <glm/glm.hpp>
+
 #include "content/Content.h"
 #include "window/Window.h"
 #include "window/Events.h"
 #include "window/input.h"
 #include "voxels/Block.h"
 
+using glm::vec3;
+
 // All in-game definitions (blocks, items, etc..)
 void setup_definitions(ContentBuilder* builder) {
 	Block* block = new Block("core:air", "air");
@@ -71,7 +75,7 @@ void setup_definitions(ContentBuilder* builder) {
 	block->lightPassing = true;
 	block->obstacle = false;
 	block->model = BlockModel::xsprite;
-	block->hitboxScale = 0.7f;
+	block->hitbox.scale(vec3(0.7f), vec3(0.5f, 0.0f, 0.5f));
 	builder->add(block);
 
 	block = new Block("base:flower", "flower");
@@ -79,6 +83,7 @@ void setup_definitions(ContentBuilder* builder) {
 	block->lightPassing = true;
 	block->obstacle = false;
 	block->model = BlockModel::xsprite;
+	block->hitbox.scale(vec3(0.7f));
 	builder->add(block);
 
 	block = new Block("base:brick", "brick");

src/frontend/world_render.cpp

@@ -31,6 +31,7 @@
 #include "graphics/Skybox.h"
 
 using glm::vec3;
+using glm::vec4;
 using std::string;
 using std::shared_ptr;
 
@@ -168,9 +169,11 @@ void WorldRenderer::draw(const GfxContext& pctx, Camera* camera, bool occlusion)
 			linesShader->use();
 			linesShader->uniformMatrix("u_projview", camera->getProjView());
 			lineBatch->lineWidth(2.0f);
-			float size = block->hitboxScale;
-			lineBatch->box(pos.x+0.5f, pos.y+size*0.5f, pos.z+0.5f, 
-						   size, size, size, 0, 0, 0, 0.5f);
+
+			const AABB& hitbox = block->hitbox;
+			const vec3 center = pos + hitbox.center();
+			const vec3 size = hitbox.size();
+			lineBatch->box(center, size, vec4(0.0f, 0.0f, 0.0f, 0.5f));
 			lineBatch->render();
 		}
 		skybox->unbind();

src/graphics/LineBatch.h

@@ -2,6 +2,7 @@
 #define GRAPHICS_LINEBATCH_H_
 
 #include <stdlib.h>
+#include <glm/glm.hpp>
 
 class Mesh;
 
@@ -19,6 +20,11 @@ public:
 	void box(float x, float y, float z, float w, float h, float d,
 			float r, float g, float b, float a);
 
+	inline void box(glm::vec3 xyz, glm::vec3 whd, glm::vec4 rgba) {
+		return box(xyz.x, xyz.y, xyz.z, whd.x, whd.y, whd.z,
+				   rgba.r, rgba.g, rgba.b, rgba.a);
+	}
+
 	void render();
 	void lineWidth(float width);
 };

src/maths/aabb.h

@@ -5,13 +5,20 @@
 
 // Axis Aligned Bounding Box
 struct AABB {
-	glm::vec3 a;
-    glm::vec3 b;
+	glm::vec3 a {0.0f};
+    glm::vec3 b {1.0f};
 
+    /* Get AABB point with minimal x,y,z */
     inline glm::vec3 min() const {
         return glm::min(a, b);
     }
 
+    /* Get AABB point with minimal x,y,z */
+    inline glm::vec3 max() const {
+        return glm::max(a, b);
+    }
+
+    /* Get AABB dimensions: width, height, depth */
     inline glm::vec3 size() const {
         return glm::vec3(
             fabs(b.x - a.x),
@@ -20,6 +27,27 @@ struct AABB {
         );
     }
 
+    inline glm::vec3 center() const {
+        return (a + b) * 0.5f;
+    }
+
+    /* Multiply AABB size from center */
+    inline void scale(const glm::vec3 mul) {
+        glm::vec3 center = (a + b) * 0.5f;
+        a = (a - center) * mul + center;
+        b = (b - center) * mul + center;
+    }
+
+    /* Multiply AABB size from given origin */
+    inline void scale(const glm::vec3 mul, const glm::vec3 orig) {
+        glm::vec3 beg = min();
+        glm::vec3 end = max();
+        glm::vec3 center = glm::mix(beg, end, orig);
+        a = (a - center) * mul + center;
+        b = (b - center) * mul + center;
+    }
+
+    /* Check if given point is inside */
     inline bool inside(const glm::vec3 pos) const {
         const glm::vec3 p = min();
         const glm::vec3 s = size();

src/voxels/Block.h

@@ -3,6 +3,8 @@
 
 #include <string>
 
+#include "../maths/aabb.h"
+
 #define FACE_MX 0
 #define FACE_PX 1
 #define FACE_MY 2
@@ -10,6 +12,8 @@
 #define FACE_MZ 4
 #define FACE_PZ 5
 
+#define BLOCK_AABB_GRID 16
+
 enum class BlockModel {
 	none, block, xsprite
 };
@@ -29,7 +33,13 @@ public:
 	bool selectable = true;
 	bool breakable = true;
 	bool rotatable = false;
-	float hitboxScale = 1;
+	AABB hitbox;
+
+	struct {
+		bool solid = true;
+		bool emissive = false;
+		bool hitboxGrid[BLOCK_AABB_GRID][BLOCK_AABB_GRID][BLOCK_AABB_GRID];
+	} rt;
 
 	Block(std::string name, std::string texture);
 };

src/voxels/Chunks.cpp

@@ -159,6 +159,7 @@ void Chunks::set(int x, int y, int z, int id, uint8_t states){
 		chunk->setModified(true);
 }
 
+#include <iostream>
 voxel* Chunks::rayCast(vec3 start, 
 					   vec3 dir, 
 					   float maxDist, 
@@ -207,20 +208,16 @@ voxel* Chunks::rayCast(vec3 start,
 			end.z = pz + t * dz;
 			
 			// TODO: replace this dumb solution with something better
-			if (def && def->hitboxScale < 1.0f) {
-				const float sz = def->hitboxScale;
-				const int subs = 16;
+			if (def && !def->rt.solid) {
+				const AABB& box = def->hitbox;
+				const int subs = BLOCK_AABB_GRID;
+				iend = vec3(ix, iy, iz);
+				end -= iend;
 				for (int i = 0; i < subs; i++) {
 					end.x += dx / float(subs);
 					end.y += dy / float(subs);
 					end.z += dz / float(subs);
-					if (end.x - ix >= 0.5f - sz * 0.5f && end.x - ix <= 0.5f + sz * 0.5f &&
-					    end.y - iy >= 0.0f && end.y - iy <= sz &&
-						end.z - iz >= 0.5f - sz * 0.5f && end.z - iz <= 0.5f + sz * 0.5f) {
-						iend.x = ix;
-						iend.y = iy;
-						iend.z = iz;
-
+					if (box.inside(end)) {
 						norm.x = norm.y = norm.z = 0.0f;
 						if (steppedIndex == 0) norm.x = -stepx;
 						if (steppedIndex == 1) norm.y = -stepy;