cocos-creator-template/assets/chunks/builtin/internal/particle-vs-gpu.chunk

precision mediump float;
#include <common/math/transform>
#include <builtin/internal/particle-common>
#include <builtin/uniforms/cc-local>

#pragma define CURVE_MODE_FIX 1
#pragma define CURVE_MODE_BLEND 2

#pragma define GRADIENT_MODE_FIX 1
#pragma define GRADIENT_MODE_BLEND 2

#pragma define SIMULATE_SPACE_LOCAL 0
#pragma define SIMULATE_SPACE_WORLD 1

#pragma define ANIMATION_MODE_WHOLE_SHEET 0
#pragma define ANIMATION_MODE_SINGLE_ROW 1

#pragma define COLOR_OVERTIME_RAND_OFFSET 91041.
#pragma define FORCE_OVERTIME_RAND_OFFSET 212165.
#pragma define ROTATION_OVERTIME_RAND_OFFSET 125292.
#pragma define SIZE_OVERTIME_RAND_OFFSET 39825.
#pragma define TEXTURE_ANIMATION_RAND_OFFSET 90794.
#pragma define VELOCITY_OVERTIME_RAND_OFFSET 197866.

uniform SampleConstants {
  vec4 u_sampleInfo;
};

uniform TickConstants {
  vec4 u_worldRot;
  vec4 u_timeDelta;
};

in vec4 a_position_starttime; // center position,particle start time
in vec4 a_color;
in vec4 a_dir_life;  // xyz:particle start velocity,w:particle lifetime
in float a_rndSeed;

#if !CC_INSTANCE_PARTICLE
  in vec4 a_size_uv;  // xyz:size, w:uv_0
  in vec4 a_rotation_uv;  // xyz:rotation, w:uv_1
#endif
#if CC_INSTANCE_PARTICLE
  in vec4 a_size_fid;  // xyz:size, w:fid
  in vec3 a_rotation;  // xyz:rotation
  in vec3 a_uv;
#endif

#if CC_RENDER_MODE == RENDER_MODE_MESH
  in vec3 a_texCoord;   // mesh uv
  in vec3 a_texCoord3;  // mesh vertices
  in vec3 a_normal;     // mesh normal
  in vec4 a_color1;     // mesh color
#endif

vec3 unpackCurveData (sampler2D tex, vec2 coord) {
  vec4 a = texture(tex, coord);
  vec4 b = texture(tex, coord + u_sampleInfo.y);
  float c = fract(coord.x * u_sampleInfo.x);

  return mix(a.xyz, b.xyz, c);
}

vec3 unpackCurveData (sampler2D tex, vec2 coord, out float w) {
  vec4 a = texture(tex, coord);
  vec4 b = texture(tex, coord + u_sampleInfo.y);
  float c = fract(coord.x * u_sampleInfo.x);

  w = mix(a.w, b.w, c);

  return mix(a.xyz, b.xyz, c);
}

vec4 unpackGradientData (sampler2D tex, vec2 coord) {
  return texture(tex, coord);
}

vec4 scaleAndAdd (vec4 a, vec4 b, float scale) {
  a.x += b.x * scale;
  a.y += b.y * scale;
  a.z += b.z * scale;

  return a;
}

// Vulkan compatible issue#9858, do not use large number (more than 100) in mod function
float pseudoRandom(float x) {
#if USE_VK_SHADER
  float o = x;
  x = mod(x - 1.0, 2.0) - 1.0;
  float freqVar = 10.16640753482; //3.1415927*(sqrt(5.0)+1.0);
  float y = sin(freqVar * floor(o * 0.5 - 0.5)); // some pseudorandom hash
  float v = max(0.0, 1.0-abs(x));
  v *= 0.7071067812; // fix sheared 'distance' measurements - but this is 1D so unsure it's even a good thing to try
  v = y < 0.0 ? -v : v;
  return v;
#endif
#if !USE_VK_SHADER
  float seed = mod(x, 233280.);
  float q = (seed * 9301. + 49297.) / 233280.;
  return fract(q);
#endif
}

#if COLOR_OVER_TIME_MODULE_ENABLE
  uniform sampler2D color_over_time_tex0;
  uniform ColorConstant {
    int u_color_mode;
  };
#endif

#if ROTATION_OVER_TIME_MODULE_ENABLE
  uniform sampler2D rotation_over_time_tex0;
  uniform RotationConstant {
    int u_rotation_mode;
  };
#endif

#if SIZE_OVER_TIME_MODULE_ENABLE
  uniform sampler2D size_over_time_tex0;
  uniform SizeConstant {
    int u_size_mode;
  };
#endif

#if FORCE_OVER_TIME_MODULE_ENABLE
  uniform sampler2D force_over_time_tex0;
  uniform ForceConstant {
    int u_force_mode;
    int u_force_space;
  };
#endif

#if VELOCITY_OVER_TIME_MODULE_ENABLE
  uniform sampler2D velocity_over_time_tex0;
  uniform VelocityConstant {
    int u_velocity_mode;
    int u_velocity_space;
  };
#endif

#if TEXTURE_ANIMATION_MODULE_ENABLE
  uniform sampler2D texture_animation_tex0;
  uniform AnimationConstant {
    vec4 u_anim_info;
  };
#endif

float repeat (float t, float length) {
  return t - floor(t / length) * length;
}

vec4 rotateQuat (vec4 p, vec4 q) {
  vec3 iv = cross(q.xyz, p.xyz) + q.w * p.xyz;
  vec3 res = p.xyz + 2.0 * cross(q.xyz, iv);
  return vec4(res.xyz, p.w);
}

float random (float seed) {
  seed = mod(seed, 233280.);
  float q = (seed * 9301. + 49297.) / 233280.;
  return fract(q);
}

#pragma define INDENTIFY_NEG_QUAT 10.0

vec4 toQuat(vec3 rotation) {
  vec3 rotTmp = rotation;
  float mulFactor = 1.0;
  if (rotTmp.x > INDENTIFY_NEG_QUAT * 0.5) {
    rotTmp.x -= INDENTIFY_NEG_QUAT;
    mulFactor = -1.0;
  }
  vec4 rot = vec4(rotTmp, 0.0);
  rot.w = mulFactor * sqrt(abs(1.0 - rot.x * rot.x - rot.y * rot.y - rot.z * rot.z));
  return rot;
}

vec4 gpvs_main () {
  float activeTime = u_timeDelta.x - a_position_starttime.w;
  float normalizedTime = clamp(activeTime / a_dir_life.w, 0.0, 1.0);

  vec2 timeCoord0 = vec2(normalizedTime, 0.);
  vec2 timeCoord1 = vec2(normalizedTime, 1.);

  #if CC_RENDER_MODE == RENDER_MODE_MESH
    vec2 vertIdx = vec2(a_texCoord.x, a_texCoord.y);
  #endif
  #if CC_RENDER_MODE != RENDER_MODE_MESH
    #if !CC_INSTANCE_PARTICLE
      vec2 vertIdx = vec2(a_size_uv.w, a_rotation_uv.w);
    #endif
    #if CC_INSTANCE_PARTICLE
      vec2 vertIdx = a_uv.xy;
    #endif
  #endif

  vec4 velocity = vec4(a_dir_life.xyz, 0.);
  vec4 pos = vec4(a_position_starttime.xyz, 1.);

  // size
  #if !CC_INSTANCE_PARTICLE
    vec3 size = a_size_uv.xyz;
  #endif
  #if CC_INSTANCE_PARTICLE
    vec3 size = a_size_fid.xyz;
  #endif
  #if SIZE_OVER_TIME_MODULE_ENABLE
    if (u_size_mode == CURVE_MODE_FIX) {
      size *= unpackCurveData(size_over_time_tex0, timeCoord0);
    } else {
      vec3 size_0 = unpackCurveData(size_over_time_tex0, timeCoord0);
      vec3 size_1 = unpackCurveData(size_over_time_tex0, timeCoord1);
      float factor_s = pseudoRandom(a_rndSeed + SIZE_OVERTIME_RAND_OFFSET);
      size *= mix(size_0, size_1, factor_s);
    }
  #endif

  vec3 compScale = scale.xyz * size;

  // force
  #if FORCE_OVER_TIME_MODULE_ENABLE
    vec3 forceAnim = vec3(0.);
    if (u_force_mode == CURVE_MODE_FIX) {
      forceAnim = unpackCurveData(force_over_time_tex0, timeCoord0);
    } else {
      vec3 force_0 = unpackCurveData(force_over_time_tex0, timeCoord0);
      vec3 force_1 = unpackCurveData(force_over_time_tex0, timeCoord1);
      float factor_f =  pseudoRandom(a_rndSeed + FORCE_OVERTIME_RAND_OFFSET);
      forceAnim = mix(force_0, force_1, factor_f);
    }
    vec4 forceTrack = vec4(forceAnim, 0.);
    if (u_force_space == SIMULATE_SPACE_LOCAL) {
      forceTrack = rotateQuat(forceTrack, u_worldRot);
    }
    velocity.xyz += forceTrack.xyz;
  #endif

  // velocity
  #if VELOCITY_OVER_TIME_MODULE_ENABLE
    float speedModifier0 = 1.;
    float speedModifier1 = 1.;
    vec3 velocityAnim = vec3(0.);
    if (u_velocity_mode == CURVE_MODE_FIX) {
      velocityAnim = unpackCurveData(velocity_over_time_tex0, timeCoord0, speedModifier0);
    } else {
      vec3 vectory_0 = unpackCurveData(velocity_over_time_tex0, timeCoord0, speedModifier0);
      vec3 vectory_1 = unpackCurveData(velocity_over_time_tex0, timeCoord1, speedModifier1);
      float factor_v = pseudoRandom(a_rndSeed + VELOCITY_OVERTIME_RAND_OFFSET);
      velocityAnim = mix(vectory_0, vectory_1, factor_v);
      speedModifier0 = mix(speedModifier0, speedModifier1, factor_v);
    }
    vec4 velocityTrack = vec4(velocityAnim, 0.);
    if (u_velocity_space == SIMULATE_SPACE_LOCAL) {
      velocityTrack = rotateQuat(velocityTrack, u_worldRot);
    }
    velocity.xyz += velocityTrack.xyz;
    velocity.xyz *= speedModifier0;
  #endif

  pos.xyz += velocity.xyz * normalizedTime * a_dir_life.w;

  #if !CC_USE_WORLD_SPACE
    pos = cc_matWorld * pos;
    #if CC_RENDER_MODE == RENDER_MODE_STRETCHED_BILLBOARD
      velocity = rotateQuat(velocity, u_worldRot);
    #endif
  #endif

  // rotation
  #if !CC_INSTANCE_PARTICLE
    vec3 startRotation = a_rotation_uv.xyz;
  #endif
  #if CC_INSTANCE_PARTICLE
    vec3 startRotation = a_rotation;
  #endif
  #if CC_RENDER_MODE != RENDER_MODE_MESH
    #if CC_RENDER_MODE == RENDER_MODE_BILLBOARD
      vec3 rotEuler = startRotation.xyz;
    #elif CC_RENDER_MODE == RENDER_MODE_STRETCHED_BILLBOARD
      vec3 rotEuler = vec3(0.);
    #endif
    #if CC_RENDER_MODE != RENDER_MODE_BILLBOARD && CC_RENDER_MODE != RENDER_MODE_STRETCHED_BILLBOARD
      vec3 rotEuler = vec3(0., 0., startRotation.z);
    #endif
    vec4 rot = quaternionFromEuler(rotEuler);
  #endif
  #if CC_RENDER_MODE == RENDER_MODE_MESH
    vec4 rot = quaternionFromEuler(startRotation);
  #endif

  #if ROTATION_OVER_TIME_MODULE_ENABLE
    if (u_rotation_mode == CURVE_MODE_FIX) {
      vec3 euler = unpackCurveData(rotation_over_time_tex0, timeCoord0) * normalizedTime * a_dir_life.w;
      vec4 quat = eulerToQuat(euler);
      mat3 mLocal = quatToMat3(quat);
      mat3 mStart = quatToMat3(rot);
      rot = mat3ToQuat(mStart * mLocal);
    } else {
      vec3 rotation_0 = unpackCurveData(rotation_over_time_tex0, timeCoord0);
      vec3 rotation_1 = unpackCurveData(rotation_over_time_tex0, timeCoord1);
      float factor_r = pseudoRandom(a_rndSeed + ROTATION_OVERTIME_RAND_OFFSET);
      vec3 euler = mix(rotation_0, rotation_1, factor_r) * normalizedTime * a_dir_life.w;
      #if CC_RENDER_MODE == RENDER_MODE_VERTICAL_BILLBOARD || CC_RENDER_MODE == RENDER_MODE_HORIZONTAL_BILLBOARD
        euler = vec3(0.0, 0.0, euler.z);
      #endif
      vec4 quat = eulerToQuat(euler);
      mat3 mLocal = quatToMat3(quat);
      mat3 mStart = quatToMat3(rot);
      rot = mat3ToQuat(mStart * mLocal);
    }
  #endif

  // color
  #if COLOR_OVER_TIME_MODULE_ENABLE
    if (u_color_mode == GRADIENT_MODE_FIX) {
      color = a_color * texture(color_over_time_tex0, timeCoord0);
    } else {
      vec4 color_0 = texture(color_over_time_tex0, timeCoord0);
      vec4 color_1 = texture(color_over_time_tex0, timeCoord1);
      float factor_c = pseudoRandom(a_rndSeed + COLOR_OVERTIME_RAND_OFFSET);
      color = a_color * mix(color_0, color_1, factor_c);
    }
  #endif
  #if !COLOR_OVER_TIME_MODULE_ENABLE
    color = a_color;
  #endif

  #if CC_RENDER_MODE != RENDER_MODE_MESH
    vec2 cornerOffset = vec2((vertIdx - 0.5));

    #if CC_RENDER_MODE == RENDER_MODE_STRETCHED_BILLBOARD
      rot = vec4(0.0, 0.0, 0.0, 1.0);
    #endif

    computeVertPos(pos, cornerOffset, rot, compScale
      #if CC_RENDER_MODE == RENDER_MODE_BILLBOARD || CC_RENDER_MODE == RENDER_MODE_VERTICAL_BILLBOARD
        , cc_matViewInv
      #endif
      #if CC_RENDER_MODE == RENDER_MODE_STRETCHED_BILLBOARD
        , cc_cameraPos.xyz
        , velocity
        , frameTile_velLenScale.z
        , frameTile_velLenScale.w
        #if !CC_INSTANCE_PARTICLE
          , a_size_uv.w
        #endif
        #if CC_INSTANCE_PARTICLE
          , a_uv.x
        #endif
      #endif
    );
  #endif
  #if CC_RENDER_MODE == RENDER_MODE_MESH
    mat3 rotMat = quatToMat3(rot);
    mat3 nodeMat = quatToMat3(nodeRotation);
    rotMat = nodeMat * rotMat;
    rot = mat3ToQuat(rotMat);

    mat4 xformNoScale = matrixFromRT(rot, pos.xyz);
    mat4 xform = matFromRTS(rot, pos.xyz, compScale);
    pos = xform * vec4(a_texCoord3, 1);
    vec4 normal = xformNoScale * vec4(a_normal, 0);
    color *= a_color1;
  #endif

  pos = cc_matViewProj * pos;

  float frameIndex = 0.;
  #if TEXTURE_ANIMATION_MODULE_ENABLE
    float startFrame = 0.;
    vec3 frameInfo = vec3(0.);
    if (int(u_anim_info.x) == GRADIENT_MODE_FIX) {
      frameInfo = unpackCurveData(texture_animation_tex0, timeCoord0);
    } else {
      vec3 frameInfo0 = unpackCurveData(texture_animation_tex0, timeCoord0);
      vec3 frameInfo1 = unpackCurveData(texture_animation_tex0, timeCoord1);
      float factor_t = pseudoRandom(a_rndSeed + TEXTURE_ANIMATION_RAND_OFFSET);
      frameInfo = mix(frameInfo0, frameInfo1, factor_t);
    }
    startFrame = frameInfo.x / u_anim_info.y;
    float EPSILON = 1e-6;
    frameIndex = repeat(u_anim_info.z * (frameInfo.y + startFrame), 1. + EPSILON);
  #endif
  uv = computeUV(frameIndex, vertIdx, frameTile_velLenScale.xy) * mainTiling_Offset.xy + mainTiling_Offset.zw;

  return pos;
}