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#include "../../../shared_cpp/Renderer2d.h"
#include "../../../shared_cpp/types.h"
#include "../../../shared_cpp/mathlib.h"
struct SoftbodyUpdateVertexData {
Vector2 position;
SoftbodyUpdateVertexData* left;
SoftbodyUpdateVertexData* right;
SoftbodyUpdateVertexData* top;
SoftbodyUpdateVertexData* bottom;
};
struct SoftbodyRectangle {
float32 width = 100;
float32 height = 100;
Vector2 position = Vector2(300, 400);
// Represents the density of springs that will be in the rectangle.
int32 springDensity = 10;
float32 totalTimeSeconds = 0.f;
SoftbodyUpdateVertexData* updateData = NULL;
Mesh2d mesh;
Mesh2d pointsMesh;
Vertex2d* vertices = NULL;
Vertex2d* pointsVertices = NULL;
void load(Renderer2d* renderer) {
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 - (inverseDensity / 2.f);
for (int32 y = 0; y < springDensity; y++) { // Rows
for (int32 x = 0; x < springDensity; x++) { // Columns
Vector2 position = Vector2(x * inverseDensity - halfInv, y * inverseDensity- halfInv);
vertices[vIdx] = { position, Vector4(1, 0, 0, 1) };
updateData[vIdx].position = position;
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(Vector2(300, 400));
pointsVertices = new Vertex2d[numVertices];
for (int32 v = 0; v < numVertices; v++) {
pointsVertices[v].position = vertices[v].position;
pointsVertices[v].color = Vector4(1, 1, 0, 1);
}
pointsMesh.model = mesh.model;
pointsMesh.load(pointsVertices, numVertices, renderer, GL_DYNAMIC_DRAW);
delete [] indices;
}
void update(float32 dtSeconds) {
totalTimeSeconds += dtSeconds;
for (int32 v = 0; v < pointsMesh.numVertices; v++) {
float32 r = rand();
updateData[v].position += (Vector2(cosf(r), sinf(r)) * 0.005f);
Vector2 nextPosition = Vector2(updateData[v].position.x, updateData[v].position.y);
vertices[v].position = nextPosition;
pointsVertices[v].position = nextPosition;
}
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;
}
};
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