virtualx-engine/drivers/gles3/shaders/particles.glsl
clayjohn 9ce57050a5 Add GPUParticles to the OpenGL3 renderer.
This includes collision (2D SDF, Box, Sphere, Heightmap),
attraction (Box, Sphere), and all sorting modes.

This does not include 3D SDF collisions, trails, or
manual emission.
2022-11-14 23:28:25 -08:00

501 lines
13 KiB
GLSL

/* clang-format off */
#[modes]
mode_default =
#[specializations]
MODE_3D = false
USERDATA1_USED = false
USERDATA2_USED = false
USERDATA3_USED = false
USERDATA4_USED = false
USERDATA5_USED = false
USERDATA6_USED = false
#[vertex]
#define SDF_MAX_LENGTH 16384.0
layout(std140) uniform GlobalShaderUniformData { //ubo:1
vec4 global_shader_uniforms[MAX_GLOBAL_SHADER_UNIFORMS];
};
// This needs to be outside clang-format so the ubo comment is in the right place
#ifdef MATERIAL_UNIFORMS_USED
layout(std140) uniform MaterialUniforms{ //ubo:2
#MATERIAL_UNIFORMS
};
#endif
/* clang-format on */
#define MAX_ATTRACTORS 32
#define ATTRACTOR_TYPE_SPHERE uint(0)
#define ATTRACTOR_TYPE_BOX uint(1)
#define ATTRACTOR_TYPE_VECTOR_FIELD uint(2)
struct Attractor {
mat4 transform;
vec4 extents; // Extents or radius. w-channel is padding.
uint type;
float strength;
float attenuation;
float directionality;
};
#define MAX_COLLIDERS 32
#define COLLIDER_TYPE_SPHERE uint(0)
#define COLLIDER_TYPE_BOX uint(1)
#define COLLIDER_TYPE_SDF uint(2)
#define COLLIDER_TYPE_HEIGHT_FIELD uint(3)
#define COLLIDER_TYPE_2D_SDF uint(4)
struct Collider {
mat4 transform;
vec4 extents; // Extents or radius. w-channel is padding.
uint type;
float scale;
float pad0;
float pad1;
};
layout(std140) uniform FrameData { //ubo:0
bool emitting;
uint cycle;
float system_phase;
float prev_system_phase;
float explosiveness;
float randomness;
float time;
float delta;
float particle_size;
float pad0;
float pad1;
float pad2;
uint random_seed;
uint attractor_count;
uint collider_count;
uint frame;
mat4 emission_transform;
Attractor attractors[MAX_ATTRACTORS];
Collider colliders[MAX_COLLIDERS];
};
#define PARTICLE_FLAG_ACTIVE uint(1)
#define PARTICLE_FLAG_STARTED uint(2)
#define PARTICLE_FLAG_TRAILED uint(4)
#define PARTICLE_FRAME_MASK uint(0xFFFF)
#define PARTICLE_FRAME_SHIFT uint(16)
// ParticleData
layout(location = 0) in highp vec4 color;
layout(location = 1) in highp vec4 velocity_flags;
layout(location = 2) in highp vec4 custom;
layout(location = 3) in highp vec4 xform_1;
layout(location = 4) in highp vec4 xform_2;
#ifdef MODE_3D
layout(location = 5) in highp vec4 xform_3;
#endif
#ifdef USERDATA1_USED
layout(location = 6) in highp vec4 userdata1;
#endif
#ifdef USERDATA2_USED
layout(location = 7) in highp vec4 userdata2;
#endif
#ifdef USERDATA3_USED
layout(location = 8) in highp vec4 userdata3;
#endif
#ifdef USERDATA4_USED
layout(location = 9) in highp vec4 userdata4;
#endif
#ifdef USERDATA5_USED
layout(location = 10) in highp vec4 userdata5;
#endif
#ifdef USERDATA6_USED
layout(location = 11) in highp vec4 userdata6;
#endif
out highp vec4 out_color; //tfb:
out highp vec4 out_velocity_flags; //tfb:
out highp vec4 out_custom; //tfb:
out highp vec4 out_xform_1; //tfb:
out highp vec4 out_xform_2; //tfb:
#ifdef MODE_3D
out highp vec4 out_xform_3; //tfb:MODE_3D
#endif
#ifdef USERDATA1_USED
out highp vec4 out_userdata1; //tfb:USERDATA1_USED
#endif
#ifdef USERDATA2_USED
out highp vec4 out_userdata2; //tfb:USERDATA2_USED
#endif
#ifdef USERDATA3_USED
out highp vec4 out_userdata3; //tfb:USERDATA3_USED
#endif
#ifdef USERDATA4_USED
out highp vec4 out_userdata4; //tfb:USERDATA4_USED
#endif
#ifdef USERDATA5_USED
out highp vec4 out_userdata5; //tfb:USERDATA5_USED
#endif
#ifdef USERDATA6_USED
out highp vec4 out_userdata6; //tfb:USERDATA6_USED
#endif
uniform sampler2D height_field_texture; //texunit:0
uniform float lifetime;
uniform bool clear;
uniform uint total_particles;
uniform bool use_fractional_delta;
uint hash(uint x) {
x = ((x >> uint(16)) ^ x) * uint(0x45d9f3b);
x = ((x >> uint(16)) ^ x) * uint(0x45d9f3b);
x = (x >> uint(16)) ^ x;
return x;
}
vec3 safe_normalize(vec3 direction) {
const float EPSILON = 0.001;
if (length(direction) < EPSILON) {
return vec3(0.0);
}
return normalize(direction);
}
// Needed whenever 2D sdf texture is read from as it is packed in RGBA8.
float vec4_to_float(vec4 p_vec) {
return dot(p_vec, vec4(1.0 / (255.0 * 255.0 * 255.0), 1.0 / (255.0 * 255.0), 1.0 / 255.0, 1.0)) * 2.0 - 1.0;
}
#GLOBALS
void main() {
bool apply_forces = true;
bool apply_velocity = true;
float local_delta = delta;
float mass = 1.0;
bool restart = false;
bool restart_position = false;
bool restart_rotation_scale = false;
bool restart_velocity = false;
bool restart_color = false;
bool restart_custom = false;
mat4 xform = mat4(1.0);
uint flags = 0u;
if (clear) {
out_color = vec4(1.0);
out_custom = vec4(0.0);
out_velocity_flags = vec4(0.0);
} else {
out_color = color;
out_velocity_flags = velocity_flags;
out_custom = custom;
xform[0] = xform_1;
xform[1] = xform_2;
#ifdef MODE_3D
xform[2] = xform_3;
#endif
xform = transpose(xform);
flags = floatBitsToUint(velocity_flags.w);
}
//clear started flag if set
flags &= ~PARTICLE_FLAG_STARTED;
bool collided = false;
vec3 collision_normal = vec3(0.0);
float collision_depth = 0.0;
vec3 attractor_force = vec3(0.0);
#if !defined(DISABLE_VELOCITY)
if (bool(flags & PARTICLE_FLAG_ACTIVE)) {
xform[3].xyz += out_velocity_flags.xyz * local_delta;
}
#endif
uint index = uint(gl_VertexID);
if (emitting) {
float restart_phase = float(index) / float(total_particles);
if (randomness > 0.0) {
uint seed = cycle;
if (restart_phase >= system_phase) {
seed -= uint(1);
}
seed *= uint(total_particles);
seed += index;
float random = float(hash(seed) % uint(65536)) / 65536.0;
restart_phase += randomness * random * 1.0 / float(total_particles);
}
restart_phase *= (1.0 - explosiveness);
if (system_phase > prev_system_phase) {
// restart_phase >= prev_system_phase is used so particles emit in the first frame they are processed
if (restart_phase >= prev_system_phase && restart_phase < system_phase) {
restart = true;
if (use_fractional_delta) {
local_delta = (system_phase - restart_phase) * lifetime;
}
}
} else if (delta > 0.0) {
if (restart_phase >= prev_system_phase) {
restart = true;
if (use_fractional_delta) {
local_delta = (1.0 - restart_phase + system_phase) * lifetime;
}
} else if (restart_phase < system_phase) {
restart = true;
if (use_fractional_delta) {
local_delta = (system_phase - restart_phase) * lifetime;
}
}
}
if (restart) {
flags = emitting ? (PARTICLE_FLAG_ACTIVE | PARTICLE_FLAG_STARTED | (cycle << PARTICLE_FRAME_SHIFT)) : 0u;
restart_position = true;
restart_rotation_scale = true;
restart_velocity = true;
restart_color = true;
restart_custom = true;
}
}
bool particle_active = bool(flags & PARTICLE_FLAG_ACTIVE);
uint particle_number = (flags >> PARTICLE_FRAME_SHIFT) * uint(total_particles) + index;
if (restart && particle_active) {
#CODE : START
}
if (particle_active) {
for (uint i = 0u; i < attractor_count; i++) {
vec3 dir;
float amount;
vec3 rel_vec = xform[3].xyz - attractors[i].transform[3].xyz;
vec3 local_pos = rel_vec * mat3(attractors[i].transform);
switch (attractors[i].type) {
case ATTRACTOR_TYPE_SPHERE: {
dir = safe_normalize(rel_vec);
float d = length(local_pos) / attractors[i].extents.x;
if (d > 1.0) {
continue;
}
amount = max(0.0, 1.0 - d);
} break;
case ATTRACTOR_TYPE_BOX: {
dir = safe_normalize(rel_vec);
vec3 abs_pos = abs(local_pos / attractors[i].extents.xyz);
float d = max(abs_pos.x, max(abs_pos.y, abs_pos.z));
if (d > 1.0) {
continue;
}
amount = max(0.0, 1.0 - d);
} break;
case ATTRACTOR_TYPE_VECTOR_FIELD: {
} break;
}
amount = pow(amount, attractors[i].attenuation);
dir = safe_normalize(mix(dir, attractors[i].transform[2].xyz, attractors[i].directionality));
attractor_force -= amount * dir * attractors[i].strength;
}
float particle_size = particle_size;
#ifdef USE_COLLISION_SCALE
particle_size *= dot(vec3(length(xform[0].xyz), length(xform[1].xyz), length(xform[2].xyz)), vec3(0.33333333333));
#endif
if (collider_count == 1u && colliders[0].type == COLLIDER_TYPE_2D_SDF) {
//2D collision
vec2 pos = xform[3].xy;
vec4 to_sdf_x = colliders[0].transform[0];
vec4 to_sdf_y = colliders[0].transform[1];
vec2 sdf_pos = vec2(dot(vec4(pos, 0, 1), to_sdf_x), dot(vec4(pos, 0, 1), to_sdf_y));
vec4 sdf_to_screen = vec4(colliders[0].extents.xyz, colliders[0].scale);
vec2 uv_pos = sdf_pos * sdf_to_screen.xy + sdf_to_screen.zw;
if (all(greaterThan(uv_pos, vec2(0.0))) && all(lessThan(uv_pos, vec2(1.0)))) {
vec2 pos2 = pos + vec2(0, particle_size);
vec2 sdf_pos2 = vec2(dot(vec4(pos2, 0, 1), to_sdf_x), dot(vec4(pos2, 0, 1), to_sdf_y));
float sdf_particle_size = distance(sdf_pos, sdf_pos2);
float d = vec4_to_float(texture(height_field_texture, uv_pos)) * SDF_MAX_LENGTH;
d -= sdf_particle_size;
if (d < 0.0) {
const float EPSILON = 0.001;
vec2 n = normalize(vec2(
vec4_to_float(texture(height_field_texture, uv_pos + vec2(EPSILON, 0.0))) - vec4_to_float(texture(height_field_texture, uv_pos - vec2(EPSILON, 0.0))),
vec4_to_float(texture(height_field_texture, uv_pos + vec2(0.0, EPSILON))) - vec4_to_float(texture(height_field_texture, uv_pos - vec2(0.0, EPSILON)))));
collided = true;
sdf_pos2 = sdf_pos + n * d;
pos2 = vec2(dot(vec4(sdf_pos2, 0, 1), colliders[0].transform[2]), dot(vec4(sdf_pos2, 0, 1), colliders[0].transform[3]));
n = pos - pos2;
collision_normal = normalize(vec3(n, 0.0));
collision_depth = length(n);
}
}
} else {
for (uint i = 0u; i < collider_count; i++) {
vec3 normal;
float depth;
bool col = false;
vec3 rel_vec = xform[3].xyz - colliders[i].transform[3].xyz;
vec3 local_pos = rel_vec * mat3(colliders[i].transform);
switch (colliders[i].type) {
case COLLIDER_TYPE_SPHERE: {
float d = length(rel_vec) - (particle_size + colliders[i].extents.x);
if (d < 0.0) {
col = true;
depth = -d;
normal = normalize(rel_vec);
}
} break;
case COLLIDER_TYPE_BOX: {
vec3 abs_pos = abs(local_pos);
vec3 sgn_pos = sign(local_pos);
if (any(greaterThan(abs_pos, colliders[i].extents.xyz))) {
//point outside box
vec3 closest = min(abs_pos, colliders[i].extents.xyz);
vec3 rel = abs_pos - closest;
depth = length(rel) - particle_size;
if (depth < 0.0) {
col = true;
normal = mat3(colliders[i].transform) * (normalize(rel) * sgn_pos);
depth = -depth;
}
} else {
//point inside box
vec3 axis_len = colliders[i].extents.xyz - abs_pos;
// there has to be a faster way to do this?
if (all(lessThan(axis_len.xx, axis_len.yz))) {
normal = vec3(1, 0, 0);
} else if (all(lessThan(axis_len.yy, axis_len.xz))) {
normal = vec3(0, 1, 0);
} else {
normal = vec3(0, 0, 1);
}
col = true;
depth = dot(normal * axis_len, vec3(1)) + particle_size;
normal = mat3(colliders[i].transform) * (normal * sgn_pos);
}
} break;
case COLLIDER_TYPE_SDF: {
} break;
case COLLIDER_TYPE_HEIGHT_FIELD: {
vec3 local_pos_bottom = local_pos;
local_pos_bottom.y -= particle_size;
if (any(greaterThan(abs(local_pos_bottom), colliders[i].extents.xyz))) {
continue;
}
const float DELTA = 1.0 / 8192.0;
vec3 uvw_pos = vec3(local_pos_bottom / colliders[i].extents.xyz) * 0.5 + 0.5;
float y = 1.0 - texture(height_field_texture, uvw_pos.xz).r;
if (y > uvw_pos.y) {
//inside heightfield
vec3 pos1 = (vec3(uvw_pos.x, y, uvw_pos.z) * 2.0 - 1.0) * colliders[i].extents.xyz;
vec3 pos2 = (vec3(uvw_pos.x + DELTA, 1.0 - texture(height_field_texture, uvw_pos.xz + vec2(DELTA, 0)).r, uvw_pos.z) * 2.0 - 1.0) * colliders[i].extents.xyz;
vec3 pos3 = (vec3(uvw_pos.x, 1.0 - texture(height_field_texture, uvw_pos.xz + vec2(0, DELTA)).r, uvw_pos.z + DELTA) * 2.0 - 1.0) * colliders[i].extents.xyz;
normal = normalize(cross(pos1 - pos2, pos1 - pos3));
float local_y = (vec3(local_pos / colliders[i].extents.xyz) * 0.5 + 0.5).y;
col = true;
depth = dot(normal, pos1) - dot(normal, local_pos_bottom);
}
} break;
}
if (col) {
if (!collided) {
collided = true;
collision_normal = normal;
collision_depth = depth;
} else {
vec3 c = collision_normal * collision_depth;
c += normal * max(0.0, depth - dot(normal, c));
collision_normal = normalize(c);
collision_depth = length(c);
}
}
}
}
}
if (particle_active) {
#CODE : PROCESS
}
flags &= ~PARTICLE_FLAG_ACTIVE;
if (particle_active) {
flags |= PARTICLE_FLAG_ACTIVE;
}
xform = transpose(xform);
out_xform_1 = xform[0];
out_xform_2 = xform[1];
#ifdef MODE_3D
out_xform_3 = xform[2];
#endif
out_velocity_flags.w = uintBitsToFloat(flags);
}
/* clang-format off */
#[fragment]
void main() {
}
/* clang-format on */