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#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;
Vector2 originalPoints[4];
Vector2 transformedPoints[4];
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;
}
originalPoints[0] = vertices[0].position;
originalPoints[1] = vertices[1].position;
originalPoints[2] = vertices[2].position;
originalPoints[3] = vertices[4].position;
shape.load(vertices, 6, renderer);
body.reset();
}
void update(float32 dtSeconds) {
body.update(dtSeconds);
shape.model = Mat4x4().translateByVec2(body.position);
// Note: This helps us check if the cursor is within the bounds of the
// rectangle later on.
for (int idx = 0; idx < 4; idx++) {
transformedPoints[idx] = shape.model * originalPoints[idx];
}
}
void render(OrthographicRenderer* renderer) {
shape.render(renderer);
}
void unload() {
shape.unload();
}
};
struct Circle {
OrthographicShape shape;
Rigidbody body;
float32 radius = 5.f;
void load(OrthographicRenderer* renderer, Vector4 color) {
const int32 numSegments = 36;
const float32 radiansPerSegment = (2.f * PI) / static_cast<float>(numSegments);
const int32 numVertices = numSegments * 3;
color = color.toNormalizedColor();
OrthographicVertex vertices[numSegments * 3];
for (int idx = 0; idx < numSegments; idx++) {
int vIdx = idx * 3;
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);
body.reset();
}
void update(float32 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);
EM_BOOL onMouseMove(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;
Circle pointer;
bool isIntersectingPointer = false;
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);
emscripten_set_mousemove_callback("#gl_canvas", NULL, false, onMouseMove);
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 };
pointer.load(&renderer, Vector4 { 25.f, 235.f, 235.f, 255.f });
mainLoop.run(update);
}
bool isPointInRectangle(Vector2 p, Rectangle r) {
// https://math.stackexchange.com/a/190373
Vector2 A = r.transformedPoints[0];
Vector2 B = r.transformedPoints[1];
Vector2 D = r.transformedPoints[3];
float32 amDotAb = (p - A).dot(B - A);
float32 abDotAb = (B - A).dot(B - A);
float32 amDotAd = (p - A).dot(D - A);
float32 aDDotAd = (D - A).dot(D - A);
return amDotAb > 0 && amDotAb < abDotAb && amDotAd > 0 && amDotAd < aDDotAd;
}
void update(float32 deltaTimeSeconds, void* userData) {
rectangle.update(deltaTimeSeconds);
pointer.update(deltaTimeSeconds);
if (isPointInRectangle(pointer.body.position, rectangle)) {
if (!isIntersectingPointer) {
isIntersectingPointer = true;
rectangle.body.force += pointer.body.force;
}
} else if (isIntersectingPointer) {
isIntersectingPointer = false;
}
// 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 >= 800.f) {
rectangle.body.position.x = 800.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 >= 600.f) {
rectangle.body.position.y = 600.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);
pointer.render(&renderer);
}
void unload() {
mainLoop.stop();
renderer.unload();
rectangle.unload();
pointer.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;
}
EM_BOOL onMouseMove(int eventType, const EmscriptenMouseEvent *mouseEvent, void *userData) {
if (!mainLoop.isRunning) {
return true;
}
pointer.body.force.x = static_cast<float32>(mouseEvent->movementX) * 1000.f;
pointer.body.force.y = static_cast<float32>(-mouseEvent->movementY) * 1000.f;
pointer.body.position.x = static_cast<float32>(mouseEvent->targetX);
pointer.body.position.y = static_cast<float32>(600.f - mouseEvent->targetY);
return true;
}
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