Camera Controls

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

main.cpp

@@ -120,10 +120,12 @@ private:
 	mat4x4 matProj;
 
 	vec3d vCamera={0,0,0};
+	vec3d vLookDir;
 
 	float zOffset=2;
 
 	float fTheta=0;
+	float fYaw=0;
 
 	vec3d Matrix_MultiplyVector(mat4x4 &m, vec3d &i)
 	{
@@ -313,16 +315,29 @@ public:
 	bool OnUserUpdate(float fElapsedTime) override
 	{
 		if (GetKey(olc::DOWN).bHeld) {
-			zOffset-=1*fElapsedTime;
+			vCamera.y-=8*fElapsedTime;
 		}
 		if (GetKey(olc::UP).bHeld) {
-			zOffset+=1*fElapsedTime;
+			vCamera.y+=8*fElapsedTime;
 		}
 		if (GetKey(olc::RIGHT).bHeld) {
-			fTheta-=1*fElapsedTime;
+			vCamera.x+=8*fElapsedTime;
 		}
 		if (GetKey(olc::LEFT).bHeld) {
-			fTheta+=1*fElapsedTime;
+			vCamera.x-=8*fElapsedTime;
+		}
+		vec3d vForward=Vector_Mul(vLookDir,8*fElapsedTime);
+		if (GetKey(olc::W).bHeld) {
+			vCamera=Vector_Add(vCamera,vForward);
+		}
+		if (GetKey(olc::S).bHeld) {
+			vCamera=Vector_Sub(vCamera,vForward);
+		}
+		if (GetKey(olc::A).bHeld) {
+			fYaw+=2*fElapsedTime;
+		}
+		if (GetKey(olc::D).bHeld) {
+			fYaw-=2*fElapsedTime;
 		}
 
 		// Set up rotation matrices
@@ -336,12 +351,20 @@ public:
 		matWorld=Matrix_MultiplyMatrix(matRotZ,matRotX);
 		matWorld=Matrix_MultiplyMatrix(matWorld,matTrans);
 
+		vec3d vUp={0,1,0};
+		vec3d vTarget={0,0,1};
+		mat4x4 matCameraRot=Matrix_MakeRotationY(fYaw);
+		vLookDir=Matrix_MultiplyVector(matCameraRot,vTarget);
+		vTarget=Vector_Add(vCamera,vLookDir);
+		mat4x4 matCamera = Matrix_PointAt(vCamera,vTarget,vUp);
+		mat4x4 matView=Matrix_QuickInverse(matCamera);
+
 		std::vector<triangle>vecTrianglesToRaster;
 
 		// Draw Triangles
 		for (auto&tri : meshCube.tris)
 		{
-			triangle triProjected, triTransformed;
+			triangle triProjected, triTransformed,triViewed;
 
 			triTransformed.p[0]=Matrix_MultiplyVector(matWorld,tri.p[0]);
 			triTransformed.p[1]=Matrix_MultiplyVector(matWorld,tri.p[1]);
@@ -357,18 +380,22 @@ public:
 			vec3d vCameraRay=Vector_Sub(triTransformed.p[0],vCamera);
 
 			if (Vector_DotProduct(normal,vCameraRay)<0) {
-				vec3d light_dir={0,1,-1};
+				vec3d light_dir=Vector_Mul(vLookDir, -1);
 				light_dir=Vector_Normalise(light_dir);
 
 				float dp = std::max(0.1f,Vector_DotProduct(light_dir,normal));
 
 				triTransformed.col=Pixel(255*dp*dp,255*dp*dp,255*dp*dp);
 
+				triViewed.p[0]=Matrix_MultiplyVector(matView,triTransformed.p[0]);
+				triViewed.p[1]=Matrix_MultiplyVector(matView,triTransformed.p[1]);
+				triViewed.p[2]=Matrix_MultiplyVector(matView,triTransformed.p[2]);
+
 
 				// Project triangles from 3D --> 2D
-				triProjected.p[0]=Matrix_MultiplyVector(matProj,triTransformed.p[0]);
-				triProjected.p[1]=Matrix_MultiplyVector(matProj,triTransformed.p[1]);
-				triProjected.p[2]=Matrix_MultiplyVector(matProj,triTransformed.p[2]);
+				triProjected.p[0]=Matrix_MultiplyVector(matProj,triViewed.p[0]);
+				triProjected.p[1]=Matrix_MultiplyVector(matProj,triViewed.p[1]);
+				triProjected.p[2]=Matrix_MultiplyVector(matProj,triViewed.p[2]);
 				triProjected.p[0]=Vector_Div(triProjected.p[0],triProjected.p[0].w);
 				triProjected.p[1]=Vector_Div(triProjected.p[1],triProjected.p[1].w);
 				triProjected.p[2]=Vector_Div(triProjected.p[2],triProjected.p[2].w);