From 64d9675091593b074d3ad1e71829291728914cee Mon Sep 17 00:00:00 2001
From: Matthew Kosarek <mattkae@protonmail.com>
Date: Wed, 19 May 2021 20:47:59 -0400
Subject: Removed rigidbody physics demos so that I can redo them properly

---
 2d/rigidbody/rigidbody_1/main.cpp | 158 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 158 insertions(+)
 create mode 100644 2d/rigidbody/rigidbody_1/main.cpp

(limited to '2d/rigidbody/rigidbody_1/main.cpp')

diff --git a/2d/rigidbody/rigidbody_1/main.cpp b/2d/rigidbody/rigidbody_1/main.cpp
new file mode 100644
index 0000000..26d24e2
--- /dev/null
+++ b/2d/rigidbody/rigidbody_1/main.cpp
@@ -0,0 +1,158 @@
+#include "../../../shared_cpp/OrthographicRenderer.h"
+#include "../../../shared_cpp/types.h"
+#include "../../../shared_cpp/WebglContext.h"
+#include "../../../shared_cpp/mathlib.h"
+#include "../../../shared_cpp/MainLoop.h"
+#include <cstdio>
+#include <cmath>
+#include <emscripten/html5.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <cmath>
+#include <cfloat>
+
+struct Rigidbody {
+    Vector2 force = { 0, 0 };
+    Vector2 velocity = { 0, 0 };
+    Vector2 position = { 0, 0 };
+    float32 mass = 1.f;
+
+    void reset() {
+        force = { 0, 0 };
+        velocity = { 0, 0 };
+    }
+
+    void applyForce(Vector2 f) {
+        force += f;
+    }
+
+    void applyGravity(float32 deltaTimeSeconds) {
+        velocity += (Vector2 { 0.f, -50.f } * deltaTimeSeconds);
+    }
+
+    void update(float32 deltaTimeSeconds) {
+        applyGravity(deltaTimeSeconds);
+        
+        Vector2 acceleration = force / mass;
+        velocity += (acceleration * deltaTimeSeconds);
+        position += (velocity * deltaTimeSeconds);
+        force = Vector2 { 0.f, 0.f };
+    }
+};
+
+struct Rectangle {
+	OrthographicShape shape;
+    Rigidbody body;
+
+	void load(OrthographicRenderer* renderer, Vector4 color, float32 width, float32 height) {
+        color = color.toNormalizedColor();
+
+		float32 halfWidth = width / 2.f;
+		float32 halfHeight = height / 2.f;
+
+	    OrthographicVertex vertices[6];
+		vertices[0].position = Vector2 { -halfWidth, -halfHeight };
+		vertices[1].position = Vector2 { -halfWidth, halfHeight };
+		vertices[2].position = Vector2 { halfWidth, halfHeight };
+		vertices[3].position = Vector2 { -halfWidth, -halfHeight };
+		vertices[4].position = Vector2 { halfWidth, -halfHeight };
+		vertices[5].position = Vector2 { halfWidth, halfHeight };
+		
+		for (int32 i = 0; i < 6; i++) {
+			vertices[i].color = color;
+		}
+
+		shape.load(vertices, 6, renderer);
+		body.reset();
+	}
+
+	void update(float32 dtSeconds) {
+		body.update(dtSeconds);
+		shape.model = Mat4x4().translateByVec2(body.position);
+	}
+
+	void render(OrthographicRenderer* renderer) {
+		shape.render(renderer);
+	}
+
+	void unload() {
+		shape.unload();
+	}
+};
+
+EM_BOOL onPlayClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData);
+EM_BOOL onStopClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData);
+
+void load();
+void update(float32 time, void* userData);
+void unload();
+
+WebglContext context;
+OrthographicRenderer renderer;
+MainLoop mainLoop;
+Rectangle rectangle;
+
+int main() {
+	context.init("#gl_canvas");
+    emscripten_set_click_callback("#gl_canvas_play", NULL, false, onPlayClicked);
+    emscripten_set_click_callback("#gl_canvas_stop", NULL, false, onStopClicked);
+    return 0;
+}
+
+void load() {
+    renderer.load(&context);
+
+	rectangle.load(&renderer, Vector4 { 55.f, 235.f, 35.f, 255.f }, 32.f, 32.f);
+	rectangle.body.position = Vector2 { context.width / 3.f, context.height / 3.f };
+	rectangle.body.velocity = Vector2 { 100.f, 250.f };
+
+    mainLoop.run(update);
+}
+
+void update(float32 deltaTimeSeconds, void* userData) {
+    rectangle.update(deltaTimeSeconds);
+
+    // Check collisions with walls so we don't go out of the scene. Simply reflect here.
+    if (rectangle.body.position.x <= 0.f) {
+        rectangle.body.position.x = 0.f;
+        rectangle.body.velocity = rectangle.body.velocity - Vector2 { 1.f, 0.f } * (2 * (rectangle.body.velocity.dot(Vector2 { 1.f, 0.f })));
+    }
+    if (rectangle.body.position.y <= 0.f) {
+        rectangle.body.position.y = 0.f;
+        rectangle.body.velocity = rectangle.body.velocity - Vector2 { 0.f, 1.f } * (2 * (rectangle.body.velocity.dot(Vector2 { 0.f, 1.f })));
+    } 
+    if (rectangle.body.position.x >= 640.f) {
+        rectangle.body.position.x = 640.f;
+        rectangle.body.velocity = rectangle.body.velocity - Vector2 { -1.f, 0.f } * (2 * (rectangle.body.velocity.dot(Vector2{ -1.f, 0.f })));
+    }
+    if (rectangle.body.position.y >= 480.f) {
+        rectangle.body.position.y = 480.f;
+        rectangle.body.velocity = rectangle.body.velocity - Vector2 { 0.f, -1.f } * (2 * (rectangle.body.velocity.dot(Vector2 { 0.f, -1.f }))) ;
+    }
+	
+	// Renderer
+	renderer.render();
+    rectangle.render(&renderer);
+}
+
+void unload() {
+    mainLoop.stop();
+    renderer.unload();
+    rectangle.unload();
+}
+
+//
+// Interactions with DOM handled below
+//
+EM_BOOL onPlayClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData) {
+    printf("Play clicked\n");
+    
+    load();
+    return true;
+}
+
+EM_BOOL onStopClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData) {
+    printf("Stop clicked\n");
+    unload();
+    return true;
+}
-- 
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