77 lines
1.8 KiB
Plaintext
77 lines
1.8 KiB
Plaintext
#ifdef __cplusplus
|
|
#include <string>
|
|
std::string shader_physics = R"("
|
|
#version 460
|
|
|
|
// execute 1 shader per particle. 128 executions per group
|
|
layout (local_size_x = 128, local_size_y = 1, local_size_z = 1) in;
|
|
|
|
// due to byte alignment, storing pos and dir as vec4 was required anyways.
|
|
struct particle_t {
|
|
vec4 pos;
|
|
vec4 dir;
|
|
};
|
|
|
|
const int offset_size = 8192;
|
|
const float SPEED = 1.0f;
|
|
const float SPEED_FACTOR = 25.0f;
|
|
const float BOUNCE_FACTOR = 0.75f;
|
|
const float SPREAD = 4.5f;
|
|
const float particle_lifetime = 120.0f;
|
|
const vec2 p_min = vec2(-50, -50);
|
|
const vec2 p_max = vec2(50, 50);
|
|
const vec3 inital_pos = vec3(0.0f, 1.0f, 0.0f);
|
|
const vec4 inital_dir = vec4(0.0f, 1.0f, 0.0f, 0.0f);
|
|
const vec4 GRAVITY = vec4(0.0, -9.8, 0.0, 0.0);
|
|
|
|
|
|
layout (std430, binding=0) buffer particle_buffer {
|
|
particle_t particles[];
|
|
};
|
|
|
|
layout (std430, binding=1) buffer offset_buffer {
|
|
vec4 offsets[offset_size];
|
|
};
|
|
|
|
uniform float deltaSeconds;
|
|
|
|
void resetParticle(uint i, float w) {
|
|
particles[i].dir = inital_dir * SPEED_FACTOR + offsets[i % offset_size] * SPREAD;
|
|
particles[i].pos = vec4(inital_pos, w);
|
|
}
|
|
|
|
bool checkBounds(vec2 pos) {
|
|
return pos.x > p_min.x && pos.y > p_min.y && pos.x < p_max.x && pos.y < p_max.y;
|
|
}
|
|
|
|
void main() {
|
|
uint i = gl_GlobalInvocationID.x;
|
|
|
|
vec4 pos = particles[i].pos;
|
|
vec4 dir = particles[i].dir;
|
|
|
|
dir.w += deltaSeconds;
|
|
|
|
if (dir.w > particle_lifetime) {
|
|
resetParticle(i, pos.w);
|
|
return;
|
|
}
|
|
|
|
pos += vec4(dir.xyz * SPEED * deltaSeconds, 0.0);
|
|
dir += vec4(GRAVITY.xyz * deltaSeconds, 0.0);
|
|
|
|
if (pos.y < 0 && checkBounds(pos.xy)) {
|
|
dir.y = -dir.y * BOUNCE_FACTOR;
|
|
pos.y = 0;
|
|
}
|
|
|
|
particles[i].dir = dir;
|
|
particles[i].pos = pos;
|
|
|
|
if (pos.y < -50)
|
|
resetParticle(i, pos.w);
|
|
|
|
}
|
|
|
|
")";
|
|
#endif |