diff options
Diffstat (limited to '2d/rigidbody/rigidbody_3/main.cpp')
| -rw-r--r-- | 2d/rigidbody/rigidbody_3/main.cpp | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/2d/rigidbody/rigidbody_3/main.cpp b/2d/rigidbody/rigidbody_3/main.cpp new file mode 100644 index 0000000..06f77dc --- /dev/null +++ b/2d/rigidbody/rigidbody_3/main.cpp @@ -0,0 +1,203 @@ +#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 linearForce = { 0, 0 }; + Vector2 velocity = { 0, 0 }; + Vector2 position = { 0, 0 }; + float32 mass = 1.f; + + float32 torque = 0.f; + float32 rotationalVelocity = 0.f; + float32 rotation = 0.f; + float32 momentOfInertia = 1.f; + + void reset() { + linearForce = { 0, 0 }; + velocity = { 0, 0 }; + rotationalVelocity = 0.f; + rotation = 0.f; + } + + void applyForce(Vector2 force, Vector2 pointOfApplication) { + linearForce += force; + torque += pointOfApplication.getPerp().dot(force); + } + + void applyGravity() { + applyForce(Vector2 { 0.f, -100.f }, Vector2 { 0.f, 0.f }); + } + + void update(float32 deltaTimeSeconds) { + applyGravity(); + + Vector2 acceleration = linearForce / mass; + velocity += (acceleration * deltaTimeSeconds); + position += (velocity * deltaTimeSeconds); + linearForce = Vector2 { 0.f, 0.f }; + + // New: Update the rotational velocity as well + float32 rotationalAcceleration = torque / momentOfInertia; + rotationalVelocity += (rotationalAcceleration * deltaTimeSeconds); + rotation += (rotationalVelocity * deltaTimeSeconds); + torque = 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(); + + body.momentOfInertia = (width * width + height * height) * (body.mass / 12.f); + } + + void update(float32 dtSeconds) { + body.update(dtSeconds); + shape.model = Mat4x4().translateByVec2(body.position).rotate2D(body.rotation); + + // 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(); + } +}; + + +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 r1; +Rectangle r2; + +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); + + r1.load(&renderer, Vector4 { 55.f, 235.f, 35.f, 255.f }, 128.f, 64.f); + r1.body.mass = 3.f; + r1.body.position = Vector2 { context.width / 4.f, context.height / 4.f }; + r1.body.velocity = Vector2 { 100.f, 250.f }; + + r2.load(&renderer, Vector4 { 235.f, 5.f, 35.f, 255.f }, 96.f, 64.f); + r2.body.mass = 1.f; + r2.body.position = Vector2 { context.width * (3.f / 4.f), context.height * (3.f / 4.f) }; + r2.body.velocity = Vector2 { -300.f, -150.f }; + + mainLoop.run(update); +} + +void handleCollisionWithWall(Rectangle* r) { + if (r->body.position.x <= 0.f) { + r->body.position.x = 0.f; + r->body.velocity = r->body.velocity - Vector2 { 1.f, 0.f } * (2 * (r->body.velocity.dot(Vector2 { 1.f, 0.f }))); + } + if (r->body.position.y <= 0.f) { + r->body.position.y = 0.f; + r->body.velocity = r->body.velocity - Vector2 { 0.f, 1.f } * (2 * (r->body.velocity.dot(Vector2 { 0.f, 1.f }))); + } + if (r->body.position.x >= 800.f) { + r->body.position.x = 800.f; + r->body.velocity = r->body.velocity - Vector2 { -1.f, 0.f } * (2 * (r->body.velocity.dot(Vector2{ -1.f, 0.f }))); + } + if (r->body.position.y >= 600.f) { + r->body.position.y = 600.f; + r->body.velocity = r->body.velocity - Vector2 { 0.f, -1.f } * (2 * (r->body.velocity.dot(Vector2 { 0.f, -1.f }))) ; + } +} + +void update(float32 deltaTimeSeconds, void* userData) { + r1.update(deltaTimeSeconds); + r2.update(deltaTimeSeconds); + + handleCollisionWithWall(&r1); + handleCollisionWithWall(&r2); + + + // Renderer + renderer.render(); + r1.render(&renderer); + r2.render(&renderer); +} + +void unload() { + mainLoop.stop(); + renderer.unload(); + r1.unload(); + r2.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; +} |