PGE 2.21

Emscripten overhaul, a bunch of new PGE features and utilities

Author: OneLoneCoder

examples/TEST_Camera2D.cpp

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+/*
+	Example file for olcUTIL_Camera2D.h
+
+	License (OLC-3)
+	~~~~~~~~~~~~~~~
+
+	Copyright 2018 - 2022 OneLoneCoder.com
+
+	Redistribution and use in source and binary forms, with or without
+	modification, are permitted provided that the following conditions
+	are met:
+
+	1. Redistributions or derivations of source code must retain the above
+	copyright notice, this list of conditions and the following disclaimer.
+
+	2. Redistributions or derivative works in binary form must reproduce
+	the above copyright notice. This list of conditions and the following
+	disclaimer must be reproduced in the documentation and/or other
+	materials provided with the distribution.
+
+	3. Neither the name of the copyright holder nor the names of its
+	contributors may be used to endorse or promote products derived
+	from this software without specific prior written permission.
+
+	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+	"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+	LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+	A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+	HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+	SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+	LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+	DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+	THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+	OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+	Links
+	~~~~~
+	YouTube:	https://www.youtube.com/javidx9
+	Discord:	https://discord.gg/WhwHUMV
+	Twitter:	https://www.twitter.com/javidx9
+	Twitch:		https://www.twitch.tv/javidx9
+	GitHub:		https://www.github.com/onelonecoder
+	Homepage:	https://www.onelonecoder.com
+
+	Author
+	~~~~~~
+	David Barr, aka javidx9, ©OneLoneCoder 2019, 2020, 2021, 2022
+
+*/
+
+#define OLC_PGE_APPLICATION
+#include "olcPixelGameEngine.h"
+
+#define OLC_PGEX_TRANSFORMEDVIEW
+#include "extensions/olcPGEX_TransformedView.h"
+
+#include "utilities/olcUTIL_Camera2D.h"
+
+/*
+	To demonstrate the camera, we need a world. In this case its a simle tile
+	world of 80x75 tiles, and each tile is 32x32 screen pixels.
+
+	A transformed view is used to navigate the world manually via the middle
+	mouse button in "free roam" mode, or controlled by the camera. 
+
+	Specifically a Tile Transformed View is used, which means all units for
+	drawing and for the camera are specified in tile space, i.e. 1 tile is 
+	1x1 units (regardless of pixel size)
+
+	No assets are used for this application, so the world is constructed
+	out of coloured squares so you can see you are moving through it.
+
+	Pressing "TAB" key will swap between "free roam" and "play" modes. In
+	free roam mode, you can use middle mouse button to pan and zoom around 
+	the world. The camera's visible area to the player is highlighted in red.
+	In play mode, the camera behaves as it would in a 2D game, depending upon 
+	the selected mode.
+*/
+
+class TEST_Camera2D : public olc::PixelGameEngine
+{
+public:
+	TEST_Camera2D()
+	{
+		sAppName = "Camera2D Utility Test";
+	}
+
+	// Transformed view object to make world offsetting simple
+	olc::TileTransformedView tv;
+
+	// Conveninet constants to define tile map world
+	olc::vi2d m_vWorldSize = { 80, 75 };
+	olc::vi2d m_vTileSize = { 32, 32 };
+
+	// The camera!
+	olc::utils::Camera2D camera;
+
+	// The point that represents the player, it is "tracked"
+	// by the camera
+	olc::vf2d vTrackedPoint;
+
+	// Flag whether we are in "free roam" or "play" mode
+	bool bFreeRoam = false;
+
+	// The world map, stored as a 1D array
+	std::vector<uint8_t> vWorldMap;
+
+public:
+	bool OnUserCreate() override
+	{
+		// Construct transform view
+		tv = olc::TileTransformedView(GetScreenSize(), m_vTileSize);
+		
+		// Construct Camera
+		vTrackedPoint = { 20.0f, 20.0f };		
+		camera = olc::utils::Camera2D(GetScreenSize() / m_vTileSize, vTrackedPoint);
+
+		// Configure Camera
+		camera.SetTarget(vTrackedPoint);
+		camera.SetMode(olc::utils::Camera2D::Mode::Simple);
+		camera.SetWorldBoundary({ 0.0f, 0.0f }, m_vWorldSize);
+		camera.EnableWorldBoundary(true);
+
+		// Create "tile map" world with just two tiles
+		vWorldMap.resize(m_vWorldSize.x * m_vWorldSize.y);
+		for (int i = 0; i < vWorldMap.size(); i++)
+			vWorldMap[i] = ((rand() % 20) == 1) ? 1 : 0;		
+
+		// Set background colour
+		Clear(olc::CYAN);
+		return true;
+	}
+
+	bool OnUserUpdate(float fElapsedTime) override
+	{
+		// In free roam, middle mouse button pans & zooms
+		if (bFreeRoam)
+			tv.HandlePanAndZoom();
+
+		// Handle player "physics" in response to key presses
+		olc::vf2d vVel = { 0.0f, 0.0f };
+		if (GetKey(olc::Key::W).bHeld) vVel += {0, -1};
+		if (GetKey(olc::Key::S).bHeld) vVel += {0, +1};
+		if (GetKey(olc::Key::A).bHeld) vVel += {-1, 0};
+		if (GetKey(olc::Key::D).bHeld) vVel += {+1, 0};
+		vTrackedPoint += vVel * 8.0f * fElapsedTime;
+		
+		// Switch between "free roam" and "play" mode with TAB key
+		if (GetKey(olc::Key::TAB).bPressed)
+		{
+			// Always setup camera to play mode when tab key pressed
+			tv.SetWorldOffset(camera.GetViewPosition());
+			tv.SetWorldScale(m_vTileSize);
+			bFreeRoam = !bFreeRoam;
+		}
+
+		// Switch camera mode in operation
+		if (GetKey(olc::Key::K1).bPressed) 
+			camera.SetMode(olc::utils::Camera2D::Mode::Simple);
+		if (GetKey(olc::Key::K2).bPressed) 
+			camera.SetMode(olc::utils::Camera2D::Mode::EdgeMove);
+		if (GetKey(olc::Key::K3).bPressed) 
+			camera.SetMode(olc::utils::Camera2D::Mode::LazyFollow);
+		if (GetKey(olc::Key::K4).bPressed) 
+			camera.SetMode(olc::utils::Camera2D::Mode::FixedScreens);
+
+		// Update the camera, if teh tracked object remains visible, 
+		// true is returned
+		bool bOnScreen = camera.Update(fElapsedTime);
+
+		// In "play" mode, set the transformed view to that required by
+		// the camera
+		if (!bFreeRoam)
+			tv.SetWorldOffset(camera.GetViewPosition());
+
+		// Render "tile map", by getting visible tiles
+		olc::vi2d vTileTL = tv.GetTopLeftTile().max({ 0,0 });
+		olc::vi2d vTileBR = tv.GetBottomRightTile().min(m_vWorldSize);
+		olc::vi2d vTile;
+		// Then looping through them and drawing them
+		for (vTile.y = vTileTL.y; vTile.y < vTileBR.y; vTile.y++)
+			for (vTile.x = vTileTL.x; vTile.x < vTileBR.x; vTile.x++)
+			{
+				int idx = vTile.y * m_vWorldSize.x + vTile.x;
+				
+				if (vWorldMap[idx] == 0)
+					tv.FillRectDecal(vTile, { 1.0f, 1.0f }, olc::Pixel(40, 40, 40));
+				
+				if (vWorldMap[idx] == 1)
+					tv.FillRectDecal(vTile, { 1.0f, 1.0f }, olc::Pixel(60, 60, 60));				
+			}
+
+		// Draw the "player" as a 1x1 cell
+		tv.FillRectDecal(vTrackedPoint - olc::vf2d(0.5f, 0.5f), {1.0f, 1.0f}, olc::BLUE);
+
+		// Overlay with information
+		if (bFreeRoam)
+		{
+			tv.FillRectDecal(camera.GetViewPosition(), camera.GetViewSize(), olc::PixelF(1.0f, 0.0f, 0.0f, 0.5f));
+			DrawStringPropDecal({ 2, 2 }, "TAB: Free Mode, M-Btn to Pan & Zoom", olc::YELLOW);
+		}
+		else
+			DrawStringPropDecal({ 2,2 }, "TAB: Play Mode", olc::YELLOW);
+
+		DrawStringPropDecal({ 2,12 }, "WASD  : Move", olc::YELLOW);
+		DrawStringPropDecal({ 2,22 }, "CAMERA: 1) Simple  2) EdgeMove  3) LazyFollow  4) Screens", olc::YELLOW);		
+		DrawStringPropDecal({ 2,42 }, vTrackedPoint.str(), olc::YELLOW);
+		return true;
+	}
+};
+
+int main()
+{
+	TEST_Camera2D demo;
+	if (demo.Construct(512, 480, 2, 2))
+		demo.Start();
+	return 0;
+}