Hello Cube

Co-authored-by: sigonasr2 <sigonasr2@gmail.com>

Block.cpp

@@ -1,8 +0,0 @@
-#include "Block.h"
-
-Block::Block(int x, int y, int R, int B, int G)
-{
-    X = x;
-    Y = y;
-    color = std::make_tuple(R, G, B);
-}

Block.h

@@ -1,14 +0,0 @@
-#pragma once
-#include <tuple>
-
-class Block 
-{
-public:
-    Block(){};
-    Block(int x, int y, int R, int B, int G);
-    void display(float CameraX, float CameraY, float Zoom);
-private:
-    int X;
-    int Y;
-    std::tuple<int, int, int> color;
-};

Map.cpp

@@ -1,6 +0,0 @@
-#include "Map.h"
-
-void Map::test(){
-    printf("Hello Map\n");
-}
-

Map.h

@@ -1,10 +0,0 @@
-#pragma once
-#include <stdio.h>
-
-class Player;
-
-class Map{
-    public:
-        Player*p;
-        void test();
-};

Player.cpp

@@ -1,6 +0,0 @@
-#include "Player.h"
-
-void Player::test(){
-    printf("Hello Player\n");
-}
-

Player.h

@@ -1,10 +0,0 @@
-#pragma once
-#include <stdio.h>
-
-class Map;
-
-class Player{
-    public:
-        Map*map;
-        void test();
-};

main.cpp

@@ -1,37 +1,192 @@
 #define OLC_PGE_APPLICATION
 #include "pixelGameEngine.h"
-#include <unordered_map>
-#include "Block.h"
 
-class Example : public olc::PixelGameEngine
+using namespace olc;
+
+
+struct vec3d
+{
+	float x, y, z;
+};
+
+struct triangle
+{
+	vec3d p[3];
+};
+
+struct mesh
+{
+	std::vector<triangle> tris;
+};
+
+struct mat4x4
+{
+	float m[4][4] = { 0 };
+};
+
+class olcEngine3D : public PixelGameEngine
 {
 public:
-	Example()
+	olcEngine3D()
 	{
-		sAppName = "Example";
+		sAppName = "3D Demo";
+	}
+
+
+private:
+	mesh meshCube;
+	mat4x4 matProj;
+
+	float fTheta=0;
+
+	void MultiplyMatrixVector(vec3d &i, vec3d &o, mat4x4 &m)
+	{
+		o.x = i.x * m.m[0][0] + i.y * m.m[1][0] + i.z * m.m[2][0] + m.m[3][0];
+		o.y = i.x * m.m[0][1] + i.y * m.m[1][1] + i.z * m.m[2][1] + m.m[3][1];
+		o.z = i.x * m.m[0][2] + i.y * m.m[1][2] + i.z * m.m[2][2] + m.m[3][2];
+		float w = i.x * m.m[0][3] + i.y * m.m[1][3] + i.z * m.m[2][3] + m.m[3][3];
+
+		if (w != 0.0f)
+		{
+			o.x /= w; o.y /= w; o.z /= w;
+		}
 	}
 
 public:
-	std::unordered_map<int,Block> Blocks;
 	bool OnUserCreate() override
 	{
-		// Called once at the start, so create things here
-		Blocks[126]=Block(25,10,255,255,255);
+		meshCube.tris = {
+
+		// SOUTH
+		{ 0.0f, 0.0f, 0.0f,    0.0f, 1.0f, 0.0f,    1.0f, 1.0f, 0.0f },
+		{ 0.0f, 0.0f, 0.0f,    1.0f, 1.0f, 0.0f,    1.0f, 0.0f, 0.0f },
+
+		// EAST
+		{ 1.0f, 0.0f, 0.0f,    1.0f, 1.0f, 0.0f,    1.0f, 1.0f, 1.0f },
+		{ 1.0f, 0.0f, 0.0f,    1.0f, 1.0f, 1.0f,    1.0f, 0.0f, 1.0f },
+
+		// NORTH
+		{ 1.0f, 0.0f, 1.0f,    1.0f, 1.0f, 1.0f,    0.0f, 1.0f, 1.0f },
+		{ 1.0f, 0.0f, 1.0f,    0.0f, 1.0f, 1.0f,    0.0f, 0.0f, 1.0f },
+
+		// WEST
+		{ 0.0f, 0.0f, 1.0f,    0.0f, 1.0f, 1.0f,    0.0f, 1.0f, 0.0f },
+		{ 0.0f, 0.0f, 1.0f,    0.0f, 1.0f, 0.0f,    0.0f, 0.0f, 0.0f },
+
+		// TOP
+		{ 0.0f, 1.0f, 0.0f,    0.0f, 1.0f, 1.0f,    1.0f, 1.0f, 1.0f },
+		{ 0.0f, 1.0f, 0.0f,    1.0f, 1.0f, 1.0f,    1.0f, 1.0f, 0.0f },
+
+		// BOTTOM
+		{ 1.0f, 0.0f, 1.0f,    0.0f, 0.0f, 1.0f,    0.0f, 0.0f, 0.0f },
+		{ 1.0f, 0.0f, 1.0f,    0.0f, 0.0f, 0.0f,    1.0f, 0.0f, 0.0f },
+
+		};
+
+		// Projection Matrix
+		float fNear = 0.1f;
+		float fFar = 1000.0f;
+		float fFov = 90.0f;
+		float fAspectRatio = (float)ScreenHeight() / (float)ScreenWidth();
+		float fFovRad = 1.0f / tanf(fFov * 0.5f / 180.0f * 3.14159f);
+
+		matProj.m[0][0] = fAspectRatio * fFovRad;
+		matProj.m[1][1] = fFovRad;
+		matProj.m[2][2] = fFar / (fFar - fNear);
+		matProj.m[3][2] = (-fFar * fNear) / (fFar - fNear);
+		matProj.m[2][3] = 1.0f;
+		matProj.m[3][3] = 0.0f;
+
 		return true;
 	}
 
 	bool OnUserUpdate(float fElapsedTime) override
 	{
+		// Set up rotation matrices
+		mat4x4 matRotZ, matRotX;
+		fTheta += 1.0f * fElapsedTime;
+
+		// Rotation Z
+		matRotZ.m[0][0] = cosf(fTheta);
+		matRotZ.m[0][1] = sinf(fTheta);
+		matRotZ.m[1][0] = -sinf(fTheta);
+		matRotZ.m[1][1] = cosf(fTheta);
+		matRotZ.m[2][2] = 1;
+		matRotZ.m[3][3] = 1;
+
+		// Rotation X
+		matRotX.m[0][0] = 1;
+		matRotX.m[1][1] = cosf(fTheta * 0.5f);
+		matRotX.m[1][2] = sinf(fTheta * 0.5f);
+		matRotX.m[2][1] = -sinf(fTheta * 0.5f);
+		matRotX.m[2][2] = cosf(fTheta * 0.5f);
+		matRotX.m[3][3] = 1;
+
+		// Draw Triangles
+		for (auto&tri : meshCube.tris)
+		{
+			triangle triProjected, triTranslated, triRotatedZ, triRotatedZX;
+
+			// Rotate in Z-Axis
+			MultiplyMatrixVector(tri.p[0], triRotatedZ.p[0], matRotZ);
+			MultiplyMatrixVector(tri.p[1], triRotatedZ.p[1], matRotZ);
+			MultiplyMatrixVector(tri.p[2], triRotatedZ.p[2], matRotZ);
+
+			// Rotate in X-Axis
+			MultiplyMatrixVector(triRotatedZ.p[0], triRotatedZX.p[0], matRotX);
+			MultiplyMatrixVector(triRotatedZ.p[1], triRotatedZX.p[1], matRotX);
+			MultiplyMatrixVector(triRotatedZ.p[2], triRotatedZX.p[2], matRotX);
+
+			// Offset into the screen
+			triTranslated = triRotatedZX;
+			triTranslated.p[0].z = triRotatedZX.p[0].z + 3.0f;
+			triTranslated.p[1].z = triRotatedZX.p[1].z + 3.0f;
+			triTranslated.p[2].z = triRotatedZX.p[2].z + 3.0f;
+
+			// Project triangles from 3D --> 2D
+			MultiplyMatrixVector(triTranslated.p[0], triProjected.p[0], matProj);
+			MultiplyMatrixVector(triTranslated.p[1], triProjected.p[1], matProj);
+			MultiplyMatrixVector(triTranslated.p[2], triProjected.p[2], matProj);
+
+			// Scale into view
+			triProjected.p[0].x += 1.0f; triProjected.p[0].y += 1.0f;
+			triProjected.p[1].x += 1.0f; triProjected.p[1].y += 1.0f;
+			triProjected.p[2].x += 1.0f; triProjected.p[2].y += 1.0f;
+			triProjected.p[0].x *= 0.5f * (float)ScreenWidth();
+			triProjected.p[0].y *= 0.5f * (float)ScreenHeight();
+			triProjected.p[1].x *= 0.5f * (float)ScreenWidth();
+			triProjected.p[1].y *= 0.5f * (float)ScreenHeight();
+			triProjected.p[2].x *= 0.5f * (float)ScreenWidth();
+			triProjected.p[2].y *= 0.5f * (float)ScreenHeight();
+
+			// Rasterize triangle
+			SetDecalMode(DecalMode::WIREFRAME);
+			DrawPolygonDecal(nullptr,{
+				{triProjected.p[0].x, triProjected.p[0].y},
+				{triProjected.p[1].x, triProjected.p[1].y},
+				{triProjected.p[2].x, triProjected.p[2].y}
+			},{
+				{0,0},
+				{0,0},
+				{0,0},
+			});
+
+		}
+
+
 		return true;
 	}
+
 };
 
 
+
+
 int main()
 {
-	Example demo;
-	if (demo.Construct(256, 240, 4, 4))
+	olcEngine3D demo;
+	if (demo.Construct(1280, 720, 1, 1))
 		demo.Start();
-
     return 0;
 }
+