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#include "undamped.h"
#include "../../../shared_cpp/Renderer2d.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>
namespace Undamped {
struct SpringWeight {
Mesh2d shape;
float32 radius = 2.f;
float32 mass = 1.f;
void load(Renderer2d* renderer, float32 inMass, Vector4 startColor, Vector4 endColor);
void update(float32 dtSeconds);
void render(Renderer2d* renderer);
void unload();
};
struct Spring {
SpringWeight* weight;
// -- Rendering
Mesh2d shape;
Vertex2d* vertices = NULL;
int32 numSegments = 0;
int32 numVertices = 0;
// -- Spring initial variables
float32 k = 4; // Spring Constant, in N / m
float32 initialDisplacement = 3.f;
float32 initialVelocity = 0.f;
// -- Spring runtime variables
float32 angularVelocity = 0.f;
float32 displacement = 0.f;
float32 timeElapsed = 0.f;
void load(Renderer2d* renderer, SpringWeight* inWieight, float32 length, float32 inInitialDisplacement, float32 inK, float32 loopRadius);
void update(float32 dtSeconds);
void render(Renderer2d* renderer);
void unload();
};
UndampedInitVariables initVariables;
void setInitVariables(UndampedInitVariables newVariables) { initVariables = newVariables; }
UndampedInitVariables getInitVariables() { return initVariables; }
WebglContext* context;
Renderer2d renderer;
MainLoop mainLoop;
SpringWeight weight;
Spring spring;
EM_BOOL onUndampedPlayClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData);
EM_BOOL onUndampedStopClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData);
void load();
void update(float32 deltaTimeSeconds, void* userData);
void unload();
void init(WebglContext* inContext) {
context = inContext;
emscripten_set_click_callback("#gl_canvas_play_undamped", NULL, false, onUndampedPlayClicked);
emscripten_set_click_callback("#gl_canvas_stop_undamped", NULL, false, onUndampedStopClicked);
}
void load() {
context->init("#gl_canvas_undamped");
renderer.load(context);
weight.load(&renderer, initVariables.mass, Vector4 { 55.f, 235.f, 35.f, 255.f }, Vector4 { 235.f, 5.f, 235.f, 255.f });
spring.load(&renderer, &weight, initVariables.springLength, initVariables.initialDisplacement, initVariables.k, 64.f);
mainLoop.run(update);
}
void update(float32 deltaTimeSeconds, void* userData) {
// -- Update
spring.update(deltaTimeSeconds);
weight.update(deltaTimeSeconds);
// -- Render
renderer.render();
weight.render(&renderer);
spring.render(&renderer);
}
void unload() {
mainLoop.stop();
renderer.unload();
weight.unload();
spring.unload();
context->destroy();
}
void SpringWeight::load(Renderer2d* renderer, float32 inMass, Vector4 startColor, Vector4 endColor) {
mass = inMass;
radius = mass * 16.f;
const int32 numSegments = 96;
const float32 radiansPerSegment = (2.f * PI) / static_cast<float>(numSegments);
const int32 numVertices = numSegments * 3;
float32 t = 0.f;
float32 tIncrement = 1.f / (numSegments / 2.f);
startColor = startColor.toNormalizedColor();
endColor = endColor.toNormalizedColor();
Vertex2d vertices[numVertices];
for (int idx = 0; idx < numSegments; idx++) {
int vIdx = idx * 3;
Vector4 color = lerp(startColor, endColor, t);
if (idx >= numSegments / 2) {
t -= tIncrement;
} else {
t += tIncrement;
}
vertices[vIdx].color = color;
vertices[vIdx].position = Vector2 { radius * cosf(radiansPerSegment * idx), radius * sinf(radiansPerSegment * idx) };
vertices[vIdx + 1].color = color;
vertices[vIdx + 1].position = Vector2 { 0.f, 0.f };
vertices[vIdx + 2].color = color;
vertices[vIdx + 2].position = Vector2 { radius * cosf(radiansPerSegment * (idx + 1)), radius * sinf(radiansPerSegment * (idx + 1)) };
}
shape.load(vertices, numVertices, renderer);
}
void SpringWeight::update(float32 dtSeconds) {
}
void SpringWeight::render(Renderer2d* renderer) {
shape.render(renderer);
}
void SpringWeight::unload() {
shape.unload();
}
void Spring::load(Renderer2d* renderer, SpringWeight* inWeight, float32 length, float32 inInitialDisplacement, float32 inK, float32 loopRadius) {
weight = inWeight;
initialDisplacement = inInitialDisplacement;
displacement = 0;
k = inK;
angularVelocity = sqrtf(k / weight->mass);
timeElapsed = 0.f;
const int32 verticesPerSegment = 6;
numSegments = 256;
numVertices = numSegments * verticesPerSegment;
vertices = new Vertex2d[numVertices];
float32 lengthIncrement = length / static_cast<float32>(numSegments);
const float32 frequency = 0.25f;
const float32 loopWidth = 20.f;
const float32 offset = 0.25f;
int32 vidx = 0;
for (int pidx = 0; pidx < numSegments; pidx++) {
float32 y1 = lengthIncrement * pidx;
float32 x1 = loopWidth * sinf(frequency * y1 + offset);
float32 y2 = y1 + lengthIncrement;
float32 x2 = loopWidth * sinf(frequency * y2 + offset);
vertices[vidx++].position = Vector2(x1, y1);
vertices[vidx++].position = Vector2(x1, y2);
vertices[vidx++].position = Vector2(x2, y1);
vertices[vidx++].position = Vector2(x2, y1);
vertices[vidx++].position = Vector2(x1, y2);
vertices[vidx++].position = Vector2(x2, y2);
}
shape.load(vertices, numVertices, renderer, GL_DYNAMIC_DRAW);
shape.model = Mat4x4().translateByVec2(Vector2(400, 300));
weight->shape.model = shape.model.translateByVec2(Vector2(0, -weight->radius));
}
void Spring::update(float32 dtSeconds) {
timeElapsed += dtSeconds;
float32 lastDisplacement = displacement;
displacement = initialDisplacement * cosf(angularVelocity * timeElapsed - initialVelocity);
float32 dx = displacement - lastDisplacement;
int32 vidx = 0;
for (int pidx = 0; pidx < numSegments; pidx++) {
float32 y1Offset = dx * (1.f - pidx / static_cast<float32>(numSegments));
float32 y2Offset = dx * (1.f - (pidx + 1) / static_cast<float32>(numSegments));
vertices[vidx++].position.y += y1Offset;
vertices[vidx++].position.y += y2Offset;
vertices[vidx++].position.y += y1Offset;
vertices[vidx++].position.y += y1Offset;
vertices[vidx++].position.y += y2Offset;
vertices[vidx++].position.y += y2Offset;
}
weight->shape.model = weight->shape.model.translateByVec2(Vector2(0, dx));
}
void Spring::render(Renderer2d* renderer) {
glBindBuffer(GL_ARRAY_BUFFER, shape.vbo);
glBufferSubData(GL_ARRAY_BUFFER, 0, numVertices * sizeof(Vertex2d), &vertices[0]);
shape.render(renderer);
}
void Spring::unload() {
shape.unload();
delete[] vertices;
}
EM_BOOL onUndampedPlayClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData) {
printf("Play clicked\n");
load();
return true;
}
EM_BOOL onUndampedStopClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData) {
printf("Stop clicked\n");
unload();
return true;
}
}
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