feat: added the ability to render whole model

fastmath.hpp

@@ -55,6 +55,12 @@ struct decimal {
     friend bool operator>(const decimal &d1, const decimal &d2) {
         return d1.i > d2.i;
     }
+    friend bool operator<=(const decimal &d1, const decimal &d2) {
+        return d1.i <= d2.i;
+    }
+    friend bool operator>=(const decimal &d1, const decimal &d2) {
+        return d1.i >= d2.i;
+    }
 
     friend bool operator==(const decimal &d1, const decimal &d2) {
         return d1.i == d2.i;
@@ -62,7 +68,6 @@ struct decimal {
     friend bool operator!=(const decimal &d1, const decimal &d2) {
         return d1.i != d2.i;
     }
-
     decimal &operator=(decimal const &in) {
         if (this != &in) {
             std::destroy_at(this);
@@ -155,6 +160,13 @@ template <int n, class Dev> struct vec {
         }
         return res;
     }
+    bool isSmall() {
+        for (int i = 0; i < n; i++) {
+            if (abs(v[i].i) > (1 << (HALF_SHIFT - 1)))
+                return false;
+        }
+        return true;
+    }
     decimal &operator[](const int &i) { return v[i]; }
 
     decimal len_sq() { return *this * *this; }

main.cpp

@@ -2,6 +2,7 @@
 #include "polygon.hpp"
 #include "renderer.hpp"
 #include "rendertarget.hpp"
+#include "testModel.hpp"
 #include <QApplication>
 #include <QImage>
 #include <QLabel>
@@ -74,9 +75,9 @@ int main(int argc, char *argv[]) {
     renderer.target = &target;
 
     polygon poly =
-        polygon(vec3(0.9, 0.9, 0.0), vec3(0.5, 0.1, 0.0), vec3(0.1, 0.9, 0.0));
+        polygon(vec3(0.9, 0.9, 1.0), vec3(0.5, 0.1, 1.0), vec3(0.1, 0.9, 1.0));
 
-    renderer.render(&poly);
+    renderer.render(&testModel);
     QApplication a(argc, argv);
 
     uint8_t *pixel = new uint8_t[64 * 64 * 3];
@@ -98,9 +99,8 @@ int main(int argc, char *argv[]) {
             addTo((target.width * y * 2 + (x * 2 + 1)) * 3, result);
             addTo((target.width * (y * 2 + 1) + (x * 2 + 1)) * 3, result);
             for (int c = 0; c < 3; c++) {
-                pixel[(WIDTH * y + x) * 3 + c] = result[c] >> 2; /*
-                     target.pixels[(target.width * y * 2 + x * 2) * 3 + c].i >>
-                     SHIFT_AMOUNT;*/
+                pixel[(WIDTH * (WIDTH - y - 1) + WIDTH - x - 1) * 3 + c] =
+                    result[c] >> 2;
             }
         }
     }

model.hpp

@@ -0,0 +1,12 @@
+
+#ifndef MODEL_H
+#define MODEL_H
+
+#include "fastmath.hpp"
+#include <vector>
+struct model {
+    std::vector<vec3> verts;
+    std::vector<uint16_t> faces;
+};
+
+#endif

parseObj.py

@@ -0,0 +1,40 @@
+# Open the file in read mode
+file = open("test.obj", "r")
+
+# Read the entire content of the file
+content = file.read().split("\n")
+
+file.close()
+
+startVerts = 0
+verts = []
+for index,line in enumerate(content):
+    if line[0] == 'o':
+        startVerts = index + 1
+        content = content[startVerts:]
+        break
+
+for index,line in enumerate(content):
+    if "vn" in line:
+        endVerts = index
+        verts = content[:endVerts]
+        content = content[endVerts:]
+        break
+
+startFaces = 0;
+faces = []
+for index,line in enumerate(content):
+    if line[0] == 'f':
+        startFaces = index
+        faces = content[startFaces:-1]
+        break
+
+verts = ["vec3(" +",".join(vert.split(" ")[1:4]) + ")" for vert in verts]
+faces = [ ",".join([str(int((d.split("/")[0])) - 1) for d in face.split(" ")[1:4]]) for face in faces]
+
+out = "#include \"model.hpp\" \n const model testModel({" + ",".join(verts) +"},{" + ",".join(faces) + "});"
+
+with open("testModel.hpp", "w") as f:
+  f.write(out)
+print(out)
+# Close the file

polygon.hpp

@@ -4,25 +4,48 @@
 #include "fastmath.hpp"
 struct polygon {
 
-    const vec3 points[3];
+    vec3 points[3];
+    vec3 delta[3];
+    bool skip = false;
 
     polygon(const vec3 &v1, const vec3 &v2, const vec3 &v3)
         : points{v1, v2, v3} {}
+    polygon() : points{} {}
+
+    void calcDelta() {
 
-    bool contains(const vec3 &p) {
         for (int i = 0; i < 3; i++) {
             int n = (i + 1) % 3;
 
             vec3 d = points[n] - points[i];
-            d = vec3(d.y(), -d.x(), d.z());
+            delta[i] = vec3(d.y(), -d.x(), d.z());
+            if (delta[i].isSmall()) {
+                skip = true;
+                return;
+            }
+        }
+    }
+
+    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 * d < decimal(0.0))
+            if (s.isSmall())
+                return false;
+            if (s * delta[i] <= decimal(0.0))
                 return false;
         }
         return true;
     }
+    friend std::ostream &operator<<(std::ostream &os, const polygon &p) {
+        for (int i = 0; i < 3; i++) {
+            os << p.points[i];
+        }
+        return os;
+    }
 };
 
 #endif

renderer.hpp

@@ -3,6 +3,7 @@
 #define RENDERER_H
 
 #include "fastmath.hpp"
+#include "model.hpp"
 #include "polygon.hpp"
 #include "rendertarget.hpp"
 #include <memory.h>
@@ -15,26 +16,49 @@ class Renderer {
     bool clearTarget = true;
     Renderer() : clearTarget(false) {}
 
-    void render(polygon *p) {
-        decimal widthScale = decimal(1.0) / decimal((float)target->width);
-        decimal heightScale = decimal(1.0) / decimal((float)target->height);
+    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 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;
-        vec3 pos = vec3();
 
         if (clearTarget) {
             memset((wchar_t *)target->pixels, 0,
                    target->height * target->width * sizeof(target[0]));
         }
 
-        for (int x = 0; x < target->height; x++) {
-            for (int y = 0; y < target->height; y++) {
-                if (p->contains(pos)) {
-                    target->set(x, y, vec3(0.0, 255.0, 0.0));
-                }
-                pos.y() += heightScale;
+        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]];
+            }
+
+            toScreenSpace(&testP);
+
+            testP.calcDelta();
+            vec3 pos = vec3();
+            for (int x = 0; x < target->height; x++) {
+                for (int y = 0; y < target->height; y++) {
+                    if (testP.contains(pos)) {
+                        target->set(x, y, vec3(0.0, 255.0, 0.0));
+                    }
+                    pos.y() += heightScale;
+                }
+                pos.y() = decimal(0);
+                pos.x() += widthScale;
             }
-            pos.y() = decimal(0);
-            pos.x() += widthScale;
         }
     }
 };