Rudimentary gravity

This commit is contained in:
Johan Maasing 2025-01-27 20:29:50 +01:00
parent a2f1e11af8
commit d6b3be83d5
3 changed files with 56 additions and 32 deletions

View file

@ -2,16 +2,16 @@
#include <cstring>
#include "simulation.h"
void printGrid(simulation::SimulationGrid grid)
void printGrid(simulation::SimulationGrid* grid)
{
std::cout << std::string(grid.x_max+2, '_') << std::endl;
for (unsigned char y = grid.y_max; y > 0; y--)
std::cout << std::string(grid->x_max+2, '_') << std::endl;
for (unsigned char y = grid->y_max; y > 0; y--)
{
std::cout << "|";
for (unsigned char x = 0; x < grid.x_max; x++)
for (unsigned char x = 0; x < grid->x_max; x++)
{
unsigned int offset = simulation::getCellOffset(x, y-1, 0, grid);
unsigned int material = grid.out[offset];
unsigned int offset = getCellOffset(x, y-1, 0, grid);
unsigned int material = grid->out[offset];
switch (material)
{
case simulation::VACUUM:
@ -26,12 +26,12 @@ void printGrid(simulation::SimulationGrid grid)
}
std::cout << "|" << std::endl;
}
std::cout << std::string(grid.x_max+2, '_') << std::endl;
std::cout << std::string(grid->x_max+2, '_') << std::endl;
}
void initGrid(simulation::SimulationGrid grid) {
unsigned int offset = simulation::getCellOffset(0,1,0, grid);
grid.in[offset] = simulation::WATER;
void initGrid(simulation::SimulationGrid* grid) {
unsigned int offset = simulation::getCellOffset(0,2,0, grid);
grid->in[offset] = simulation::WATER;
}
int main() {
@ -50,11 +50,11 @@ int main() {
zMax
};
initGrid(grid);
step(0, grid);
initGrid(&grid);
for (int n=0; n< 2; n++) {
printGrid(grid);
simulation::step(0, &grid);
printGrid(&grid);
prepareForNextStep(&grid);
}
std::free(inCells);
std::free(outCells);

View file

@ -1,16 +1,17 @@
#include "simulation.h"
#include <cstring>
namespace simulation
{
unsigned int getCellOffset(
int getCellOffset(
unsigned char x,
unsigned char y,
unsigned char z,
SimulationGrid grid)
SimulationGrid* grid)
{
if (x < grid.x_max && y < grid.y_max && z < grid.z_max)
if (x < grid->x_max && y < grid->y_max && z < grid->z_max)
{
unsigned int offset = x + y * grid.x_max + z * (grid.y_max * grid.x_max);
int offset = x + y * grid->x_max + z * (grid->y_max * grid->x_max);
return offset;
}
return -1;
@ -18,33 +19,55 @@ namespace simulation
void step(
double millisecondsSinceLastStep,
SimulationGrid grid)
SimulationGrid* grid)
{
for (unsigned char x = 0; x < grid.x_max; x++)
for (unsigned char x = 0; x < grid->x_max; x++)
{
for (unsigned char y = 0; y < grid.y_max; y++)
for (unsigned char y = 0; y < grid->y_max; y++)
{
for (unsigned char z = 0; z < grid.z_max; z++)
for (unsigned char z = 0; z < grid->z_max; z++)
{
unsigned int offset = getCellOffset(x, y, z, grid);
unsigned int material = grid.in[offset];
int offset = getCellOffset(x, y, z, grid);
unsigned int material = grid->in[offset];
switch (material)
{
case WATER:
if (y > 0)
{
unsigned int downOffset = getCellOffset(x, y - 1, z, grid);
int downOffset = getCellOffset(x, y - 1, z, grid);
// Flow down if cell is empty
if (grid.out[downOffset] == 0)
if (downOffset >= 0 && grid->out[downOffset] == 0)
{
grid.out[downOffset] = material;
grid->out[downOffset] = material;
grid->out[offset] = VACUUM;
} else
{
// Stay in the same location
grid->out[offset] = material;
}
break;
}
case MERCURY:
{
break;
}
default:
grid.out[offset] = material;
{
grid->out[offset] = material;
}
}
}
}
}
}
void prepareForNextStep(SimulationGrid* grid)
{
// Flip the buffers
unsigned int* inCells = grid->in;
grid->in = grid->out;
grid->out = inCells;
// Clear out buffer
size_t bufferSizeInBytes = sizeof(unsigned int) * grid->x_max * grid->y_max * grid->z_max;
std::memset(grid->out, VACUUM, bufferSizeInBytes);
}
}

View file

@ -24,15 +24,16 @@ namespace simulation
void step(
double millisecondsSinceLastStep,
SimulationGrid grid
SimulationGrid* grid
);
unsigned int getCellOffset(
int getCellOffset(
unsigned char x,
unsigned char y,
unsigned char z,
SimulationGrid grid);
SimulationGrid* grid);
void prepareForNextStep(SimulationGrid* grid);
}
#endif //SIMULATION_H