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#include "../../../shared_cpp/Renderer2d.h"
#include "../../../shared_cpp/types.h"
#include "../../../shared_cpp/mathlib.h"
struct SoftbodyUpdateVertexData {
Vector2 position; // Position is in world coordinates, for math's sake.
Vector2 displacement;
Vector2 initialVelocity;
Vector2 initialDisplacement;
bool isHovered = false;
SoftbodyUpdateVertexData* left;
SoftbodyUpdateVertexData* right;
SoftbodyUpdateVertexData* top;
SoftbodyUpdateVertexData* bottom;
};
EM_BOOL onMouseMove(int eventType, const EmscriptenMouseEvent *mouseEvent, void *userData);
EM_BOOL onMouseDown(int eventType, const EmscriptenMouseEvent *mouseEvent, void *userData);
EM_BOOL onMouseUp(int eventType, const EmscriptenMouseEvent *mouseEvent, void *userData);
struct SoftbodyRectangle {
float32 width = 200;
float32 height = 200;
Vector2 position;
int32 springDensity = 10;
float32 springConstant = 4.f; // in N /m
float32 jointMassKg = 10;
float32 angularVelocity = 0.f;
// Runtime data
float32 totalTimeSeconds = 0.f;
SoftbodyUpdateVertexData* updateData = NULL;
bool hasLastPositionChanged = false;
Vector2 lastMousePosition;
SoftbodyUpdateVertexData* draggedVertex = NULL;
// Render data
Mesh2d mesh;
Mesh2d pointsMesh;
Vertex2d* vertices = NULL;
Vertex2d* pointsVertices = NULL;
void load(Renderer2d* renderer) {
position = Vector2(800 / 2 - width / 2, 600 / 2 - height / 2);
angularVelocity = sqrtf(springConstant / jointMassKg);
int32 numVertices = springDensity * springDensity; // Each subdivision is a square.
int32 numIndices = 6 * ((springDensity - 1) * (springDensity - 1));
vertices = new Vertex2d[numVertices];
updateData = new SoftbodyUpdateVertexData[numVertices];
auto indices = new GLuint[numIndices];
// Load a square with the desired density
int32 vIdx = 0;
int32 iIdx = 0;
float32 inverseDensity = 1.f / springDensity;
float32 halfInv = inverseDensity / 2.f;
for (int32 y = 0; y < springDensity; y++) { // Rows
for (int32 x = 0; x < springDensity; x++) { // Columns
Vector2 vpos = Vector2(x * inverseDensity - halfInv, y * inverseDensity- halfInv);
vpos.x = vpos.x * width + position.x;
vpos.y = vpos.y * height + position.y;
vertices[vIdx] = { vpos, Vector4(1, 0, 0, 1) };
updateData[vIdx].position = vpos;
updateData[vIdx].initialVelocity = Vector2(randomFloatBetween(0, 1.0) * 0.1, randomFloatBetween(0, 1.0) * 0.1);
updateData[vIdx].initialDisplacement = Vector2(randomFloatBetween(0, 1.0) * 0.1, randomFloatBetween(0, 1.0) * 0.1);
if (x != 0) updateData[vIdx].left = &updateData[vIdx - 1];
if (x != springDensity - 1) updateData[vIdx].right = &updateData[vIdx + 1];
if (y != 0) updateData[vIdx].top = &updateData[vIdx - springDensity];
if (y != springDensity - 1) updateData[vIdx].bottom = &updateData[vIdx + springDensity];
if (y != springDensity - 1 && x != springDensity - 1) {
indices[iIdx++] = vIdx;
indices[iIdx++] = vIdx + 1;
indices[iIdx++] = vIdx + springDensity;
indices[iIdx++] = vIdx + springDensity;
indices[iIdx++] = vIdx + springDensity + 1;
indices[iIdx++] = vIdx + 1;
}
vIdx++;
}
}
mesh.load(vertices, numVertices, indices, numIndices, renderer, GL_DYNAMIC_DRAW);
// mesh.model = Mat4x4().scale(Vector3(width, height, 0)).translateByVec2(position);
pointsVertices = new Vertex2d[numVertices];
for (int32 v = 0; v < numVertices; v++) {
pointsVertices[v].position = vertices[v].position;
pointsVertices[v].color = Vector4(0, 0, 0, 1);
}
//pointsMesh.model = mesh.model;
pointsMesh.load(pointsVertices, numVertices, renderer, GL_DYNAMIC_DRAW);
delete [] indices;
// Setup callbacks
emscripten_set_mousemove_callback("#gl_canvas", this, false, onMouseMove);
emscripten_set_mousedown_callback("#gl_canvas", this, false, onMouseDown);
emscripten_set_mouseup_callback("#gl_canvas", this, false, onMouseUp);
}
void update(float32 dtSeconds) {
totalTimeSeconds += dtSeconds;
for (int32 v = 0; v < pointsMesh.numVertices; v++) {
auto springWeight = &updateData[v];
//springWeight->displacement.x = springWeight->initialDisplacement.x * cosf(angularVelocity * totalTimeSeconds - springWeight->initialVelocity.x);
//springWeight->displacement.y = springWeight->initialDisplacement.y * cosf(angularVelocity * totalTimeSeconds - springWeight->initialVelocity.y);
//Vector2 nextPosition = springWeight->position + springWeight->displacement;
//vertices[v].position = nextPosition;
//pointsVertices[v].position = nextPosition;
if (springWeight == draggedVertex && hasLastPositionChanged) {
hasLastPositionChanged = false;
vertices[v].position = lastMousePosition;
pointsVertices[v].position = lastMousePosition;
}
if (!draggedVertex && hasLastPositionChanged) {
if ((springWeight->position - lastMousePosition).length() < 10.f) {
pointsVertices[v].color = Vector4(1, 1, 0, 1);
springWeight->isHovered = true;
}
else {
pointsVertices[v].color = Vector4(0, 0, 0, 1);
springWeight->isHovered = false;
}
}
}
if (hasLastPositionChanged) hasLastPositionChanged = false;
mesh.updateVertices(vertices);
pointsMesh.updateVertices(pointsVertices);
}
void render(Renderer2d* renderer) {
mesh.render(renderer);
pointsMesh.render(renderer, GL_POINTS);
}
void unload() {
mesh.unload();
pointsMesh.unload();
delete [] vertices;
delete [] pointsVertices;
}
};
EM_BOOL onMouseMove(int eventType, const EmscriptenMouseEvent *mouseEvent, void *userData) {
SoftbodyRectangle* rectangle = (SoftbodyRectangle*)userData;
rectangle->hasLastPositionChanged = true;
rectangle->lastMousePosition = Vector2(static_cast<float32>(mouseEvent->targetX), static_cast<float32>(600 - mouseEvent->targetY));
return true;
}
EM_BOOL onMouseDown(int eventType, const EmscriptenMouseEvent *mouseEvent, void *userData) {
SoftbodyRectangle* rectangle = (SoftbodyRectangle*)userData;
for (int32 v = 0; v < rectangle->pointsMesh.numVertices; v++) {
auto springWeight = &rectangle->updateData[v];
if (springWeight->isHovered) {
rectangle->draggedVertex = springWeight;
break;
}
}
return true;
}
EM_BOOL onMouseUp(int eventType, const EmscriptenMouseEvent *mouseEvent, void *userData) {
SoftbodyRectangle* rectangle = (SoftbodyRectangle*)userData;
rectangle->draggedVertex = NULL;
return true;
}
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