Include sorting of triangles

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

main.cpp

@@ -1,8 +1,15 @@
 #define OLC_PGE_APPLICATION
 #include "pixelGameEngine.h"
+#include <strstream>
+#include <algorithm>
 
 using namespace olc;
 
+struct vec2d
+{
+	float u,v;
+};
+
 
 struct vec3d
 {
@@ -12,11 +19,80 @@ struct vec3d
 struct triangle
 {
 	vec3d p[3];
+	vec2d uv[3];
+	Pixel col;
 };
 
 struct mesh
 {
 	std::vector<triangle> tris;
+
+	bool LoadFromObjectFile(std::string sFilename)
+	{
+		std::ifstream f(sFilename);
+		if (!f.is_open())
+			return false;
+
+		// Local cache of verts
+		std::vector<vec3d> verts;
+		std::vector<vec2d> uvs;
+
+		while (!f.eof())
+		{
+			char line[128];
+			f.getline(line, 128);
+
+			std::strstream s;
+			s << line;
+
+			char junk;
+
+			if (line[0] == 'v')
+			{
+				if (line[1]=='t') {
+					vec2d v;
+					s >> junk >> junk >> v.u >> v.v;
+					uvs.push_back(v);
+					//std::cout<<"Line: "<<line<<"\n";
+					//std::cout<<"Tex coords: "<<v.u<<","<<v.v<<"\n";
+				} else
+				if (line[1] != 'n')
+				{
+					vec3d v;
+					s >> junk >> v.x >> v.y >> v.z;
+					verts.push_back(v);
+					//std::cout<<"Line: "<<line<<"\n";
+					//std::cout<<"Vertex: "<<v.x<<","<<v.y<<","<<v.z<<"\n";
+				}
+			}
+			if (line[0] == 'f')
+				{
+					s >> junk;
+
+					std::string tokens[9];
+					int nTokenCount = -1;
+
+
+					while (!s.eof())
+					{
+						char c = s.get();
+						if (c == ' ' || c == '/')
+							nTokenCount++;
+						else
+							tokens[nTokenCount].append(1, c);
+					}
+
+					tokens[nTokenCount].pop_back();
+
+					tris.push_back({ verts[stoi(tokens[0]) - 1], verts[stoi(tokens[3]) - 1], verts[stoi(tokens[6]) - 1],
+					0,0,0
+					/*uvs[stoi(tokens[1]) - 1], uvs[stoi(tokens[4]) - 1], uvs[stoi(tokens[7]) - 1]*/});
+				}
+		}
+
+		return true;
+	}
+
 };
 
 struct mat4x4
@@ -26,7 +102,10 @@ struct mat4x4
 
 class olcEngine3D : public PixelGameEngine
 {
+
 public:
+
+	Decal*texture;
 	olcEngine3D()
 	{
 		sAppName = "3D Demo";
@@ -39,6 +118,8 @@ private:
 
 	vec3d vCamera={0,0,0};
 
+	float zOffset=2;
+
 	float fTheta=0;
 
 	void MultiplyMatrixVector(vec3d &i, vec3d &o, mat4x4 &m)
@@ -57,33 +138,8 @@ private:
 public:
 	bool OnUserCreate() override
 	{
-		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 },
-
-		};
+		texture = new Decal(new Sprite("Body.png"));
+		meshCube.LoadFromObjectFile("Nia.obj");
 
 		// Projection Matrix
 		float fNear = 0.1f;
@@ -104,9 +160,21 @@ public:
 
 	bool OnUserUpdate(float fElapsedTime) override
 	{
+		if (GetKey(olc::DOWN).bHeld) {
+			zOffset-=1*fElapsedTime;
+		}
+		if (GetKey(olc::UP).bHeld) {
+			zOffset+=1*fElapsedTime;
+		}
+		if (GetKey(olc::RIGHT).bHeld) {
+			fTheta-=1*fElapsedTime;
+		}
+		if (GetKey(olc::LEFT).bHeld) {
+			fTheta+=1*fElapsedTime;
+		}
+
 		// Set up rotation matrices
 		mat4x4 matRotZ, matRotX;
-		fTheta += 1.0f * fElapsedTime;
 
 		// Rotation Z
 		matRotZ.m[0][0] = cosf(fTheta);
@@ -124,6 +192,8 @@ public:
 		matRotX.m[2][2] = cosf(fTheta * 0.5f);
 		matRotX.m[3][3] = 1;
 
+		std::vector<triangle>vecTrianglesToRaster;
+
 		// Draw Triangles
 		for (auto&tri : meshCube.tris)
 		{
@@ -141,9 +211,9 @@ public:
 
 			// 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;
+			triTranslated.p[0].z = triRotatedZX.p[0].z + zOffset;
+			triTranslated.p[1].z = triRotatedZX.p[1].z + zOffset;
+			triTranslated.p[2].z = triRotatedZX.p[2].z + zOffset;
 
 			vec3d normal,line1,line2;
 			line1.x=triTranslated.p[1].x-triTranslated.p[0].x;
@@ -188,22 +258,45 @@ public:
 				triProjected.p[1].y *= 0.5f * (float)ScreenHeight();
 				triProjected.p[2].x *= 0.5f * (float)ScreenWidth();
 				triProjected.p[2].y *= 0.5f * (float)ScreenHeight();
+				triProjected.col=Pixel(255*dp*dp,255*dp*dp,255*dp*dp);
+
+				vecTrianglesToRaster.push_back(triProjected);
 
-				// 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},
-				},Pixel(255*dp*dp,255*dp*dp,255*dp*dp));
 			}
+		}
 
+		std::sort(vecTrianglesToRaster.begin(),vecTrianglesToRaster.end(),[](triangle&t1,triangle&t2){return (t1.p[0].z+t1.p[1].z+t1.p[2].z)/3.0f>(t2.p[0].z+t2.p[1].z+t2.p[2].z)/3.0f;});
+
+		for (auto&triProjected:vecTrianglesToRaster) {
+
+			// Rasterize triangle
+			SetDecalStructure(DecalStructure::LIST);
+			SetDecalMode(DecalMode::NORMAL);
+			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}
+			},{
+				{triProjected.uv[0].u,triProjected.uv[0].v},
+				{triProjected.uv[1].u,triProjected.uv[1].v},
+				{triProjected.uv[2].u,triProjected.uv[2].v},
+			},triProjected.col);
+			/*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},
+			},BLACK);*/
+			SetDecalStructure(DecalStructure::FAN);
 		}
 
+		SetDecalMode(DecalMode::NORMAL);
+		DrawStringDecal({0,0},"Triangles: "+std::to_string(meshCube.tris.size()));
+
 
 		return true;
 	}