feat: improved performance and fixed bugs

polygon.hpp

@@ -5,37 +5,50 @@
 struct polygon {
 
     vec3 points[3];
-    vec3 delta[3];
+    decimal delta[9];
     bool skip = false;
 
+    decimal bounding[4]; // min x, max x, min y, max y
+
     polygon(const vec3 &v1, const vec3 &v2, const vec3 &v3)
-        : points{v1, v2, v3} {}
-    polygon() : points{} {}
+        : points{v1, v2, v3}, delta{} {}
+    polygon() : points{}, delta{} {}
 
     void calcDelta() {
 
         for (int i = 0; i < 3; i++) {
             int n = (i + 1) % 3;
 
-            vec3 d = points[n] - points[i];
-            delta[i] = vec3(d.y(), -d.x(), d.z());
-            if (delta[i].isSmall()) {
-                skip = true;
-                return;
-            }
+            delta[i * 3] = points[i].y() - points[n].y();
+            delta[i * 3 + 1] = points[n].x() - points[i].x();
+            delta[i * 3 + 2] =
+                points[i].x() * points[n].y() - points[i].y() * points[n].x();
+        }
+        bounding[0] = points[0].x();
+        bounding[1] = points[0].x();
+        bounding[2] = points[0].y();
+        bounding[3] = points[0].y();
+        for (int i = 1; i < 3; i++) {
+            if (bounding[0] > points[i].x())
+                bounding[0] = points[i].x();
+            if (bounding[1] < points[i].x())
+                bounding[1] = points[i].x();
+            if (bounding[2] > points[i].y())
+                bounding[2] = points[i].y();
+            if (bounding[3] < points[i].y())
+                bounding[3] = points[i].y();
         }
     }
 
-    bool contains(const vec3 &p) {
-        if (skip)
-            return false;
+    const bool contains(const vec3 &p) {
+        // if (skip)
+        //    return false;
         for (int i = 0; i < 3; i++) {
-            int n = (i + 1) % 3;
-
-            vec3 s = p - points[n];
-            if (s.isSmall())
-                return false;
-            if (s * delta[i] <= decimal(0.0))
+            vec3 d = p;
+            if ((((d.x().i >> SHIFT_AMOUNT) * delta[i * 3].i +
+                  (d.y().i >> SHIFT_AMOUNT) * delta[i * 3 + 1].i +
+                  delta[i * 3 + 2].i) >>
+                 SHIFT_AMOUNT) > 0)
                 return false;
         }
         return true;

renderer.hpp

@@ -6,8 +6,11 @@
 #include "model.hpp"
 #include "polygon.hpp"
 #include "rendertarget.hpp"
+#include <cstring>
 #include <memory.h>
 
+#define SCREEN_SPACE_SIZE 8.0
+
 class Renderer {
 
   public:
@@ -16,47 +19,61 @@ class Renderer {
     bool clearTarget = true;
     Renderer() : clearTarget(false) {}
 
-    void toScreenSpace(polygon *p) {
-        for (int i = 0; i < 3; i++) {
-            p->points[i].x() =
-                p->points[i].x() / p->points[i].z() * decimal(8.0) +
-                decimal(8.0);
-            p->points[i].y() =
-                p->points[i].y() / p->points[i].z() * decimal(8.0) +
-                decimal(8.0);
-            p->points[i].z() = decimal(1.0);
-        }
+    void toScreenSpace(vec3 *p) {
+        p->x() = p->x() / p->z() * decimal(SCREEN_SPACE_SIZE) +
+                 decimal(SCREEN_SPACE_SIZE);
+        p->y() = p->y() / p->z() * decimal(SCREEN_SPACE_SIZE) +
+                 decimal(SCREEN_SPACE_SIZE);
+        p->z() = decimal(1.0);
     }
 
     void render(const model *model) {
-        decimal widthScale = decimal(16.0) / decimal((float)target->width);
-        decimal heightScale = decimal(16.0) / decimal((float)target->height);
-        // std::cout << widthScale << std::endl;
+        decimal widthScale =
+            decimal(SCREEN_SPACE_SIZE * 2) / decimal((float)target->width);
+        decimal heightScale =
+            decimal(SCREEN_SPACE_SIZE * 2) / decimal((float)target->height);
+
+        decimal invWidthScale =
+            decimal((float)(target->width / SCREEN_SPACE_SIZE / 2));
+        decimal invHeightScale =
+            decimal((float)(target->height / SCREEN_SPACE_SIZE / 2));
 
         if (clearTarget) {
             memset((wchar_t *)target->pixels, 0,
                    target->height * target->width * sizeof(target[0]));
         }
 
+        vec3 verts[model->verts.size()] = {};
+
+        std::copy(model->verts.begin(), model->verts.end(), verts);
+
+        for (int i = 0; i < model->verts.size(); i++) {
+            toScreenSpace(verts + i);
+        }
+
         polygon testP;
 
         for (int f = 0; f < model->faces.size(); f += 3) {
             for (int p = 0; p < 3; p++) {
-                testP.points[p] = model->verts[model->faces[f + p]];
+                testP.points[p] = verts[model->faces[f + p]];
             }
 
-            toScreenSpace(&testP);
-
             testP.calcDelta();
-            vec3 pos = vec3();
-            for (int x = 0; x < target->height; x++) {
-                for (int y = 0; y < target->height; y++) {
+
+            int startX = (testP.bounding[0] * invWidthScale).i >> SHIFT_AMOUNT;
+            int endX = (testP.bounding[1] * invWidthScale).i >> SHIFT_AMOUNT;
+            int startY = (testP.bounding[2] * invHeightScale).i >> SHIFT_AMOUNT;
+            int endY = (testP.bounding[3] * invHeightScale).i >> SHIFT_AMOUNT;
+
+            vec3 pos = vec3(testP.bounding[0], testP.bounding[2], 0.0);
+            for (int x = startX; x < endX; x++) {
+                for (int y = startY; y < endY; y++) {
                     if (testP.contains(pos)) {
                         target->set(x, y, vec3(0.0, 255.0, 0.0));
                     }
                     pos.y() += heightScale;
                 }
-                pos.y() = decimal(0);
+                pos.y() = decimal(testP.bounding[2]);
                 pos.x() += widthScale;
             }
         }