// Copyright (C) 2009 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#pragma version(1)

#pragma rs java_package_name(com.android.magicsmoke)

#include "rs_graphics.rsh"

#define RSID_NOISESRC1 1
#define RSID_NOISESRC2 2
#define RSID_NOISESRC3 3
#define RSID_NOISESRC4 4
#define RSID_NOISESRC5 5
#define RSID_NOISEDST1 6
#define RSID_NOISEDST2 7
#define RSID_NOISEDST3 8
#define RSID_NOISEDST4 9
#define RSID_NOISEDST5 10

// State set from java
float gXOffset;
float gYOffset;
int   gPreset;
int   gTextureMask;
int   gRotate;
int   gTextureSwap;
int   gProcessTextureMode;
int   gBackCol;
int   gLowCol;
int   gHighCol;
float gAlphaMul;
int   gPreMul;

typedef struct VertexShaderConstants_s {
    float4 layer0;
    float4 layer1;
    float4 layer2;
    float4 layer3;
    float4 layer4;
    float2 panoffset;
} VertexShaderConstants;
VertexShaderConstants *gVSConstants;

typedef struct FragmentShaderConstants_s {
    float4 clearColor;
} FragmentShaderConstants;
FragmentShaderConstants *gFSConstants;

typedef struct VertexInputs_s {
    float4 position;
    float2 texture0;
} VertexInputs;
VertexInputs *gVS;


rs_program_fragment gPF5tex;
rs_program_vertex gPV5tex;
rs_program_fragment gPF4tex;
rs_program_vertex gPV4tex;

rs_program_store gPStore;

rs_allocation gTnoise1;
rs_allocation gTnoise2;
rs_allocation gTnoise3;
rs_allocation gTnoise4;
rs_allocation gTnoise5;

int *gNoisesrc1;
int *gNoisesrc2;
int *gNoisesrc3;
int *gNoisesrc4;
int *gNoisesrc5;

int *gNoisedst1;
int *gNoisedst2;
int *gNoisedst3;
int *gNoisedst4;
int *gNoisedst5;

// Local script variables
static float xshift[5];
static float rotation[5];
static float scale[5];
static float alphafactor;
static int currentpreset;
static int lastuptime;
static float timedelta;
static float4 clearColor = {0.5f, 0.0f, 0.0f, 1.0f};
static int countTextures()
{
    int pos = 0;
    for (int i = 0; i < 5; i++)
    {
        if (gTextureMask & (1<<i))
            pos++;
    }
    return pos;
}
#define rotate(s, a) \
do { \
    float __agl = (3.1415927f / 180.0f) * a; \
    s.x = sin(__agl); \
    s.y = cos(__agl); \
} while (0)

static void update()
{
    rs_program_vertex pv;
    pv = gPV5tex;
    rs_program_fragment pf;
    pf = gPF5tex;

    if (countTextures() == 4)
    {
        pv = gPV4tex;
        pf = gPF4tex;
    }
    rsgBindProgramFragment(pf);
    rsgBindProgramVertex(pv);
    rsgBindProgramStore(gPStore);

    rotate(gVSConstants->layer0, rotation[0]);
    rotate(gVSConstants->layer1, rotation[1]);
    rotate(gVSConstants->layer2, rotation[2]);
    rotate(gVSConstants->layer3, rotation[3]);
    rotate(gVSConstants->layer4, rotation[4]);

    gVSConstants->layer0.w = xshift[0];
    gVSConstants->layer1.w = xshift[1];
    gVSConstants->layer2.w = xshift[2];
    gVSConstants->layer3.w = xshift[3];
    gVSConstants->layer4.w = xshift[4];

    float m = 0.35f;
    gVSConstants->layer0.z = m * scale[0];
    gVSConstants->layer1.z = m * scale[1];
    gVSConstants->layer2.z = m * scale[2];
    gVSConstants->layer3.z = m * scale[3];
    gVSConstants->layer4.z = m * scale[4];

    gVSConstants->panoffset.x = gXOffset;
    gVSConstants->panoffset.y = -gYOffset;

    gFSConstants->clearColor = clearColor;

    int pos = 0;
    for (int i = 0; i < 5; i++)
    {
        if (gTextureMask & (1<<i))
        {
            switch (i)
            {
                case 0: rsgBindTexture(pf, pos, gTextureSwap != 0 ? gTnoise5 : gTnoise1); break;
                case 1: rsgBindTexture(pf, pos, gTnoise2); break;
                case 2: rsgBindTexture(pf, pos, gTnoise3); break;
                case 3: rsgBindTexture(pf, pos, gTnoise4); break;
                case 4: rsgBindTexture(pf, pos, gTnoise5); break;
                default: break;
            }
            pos++;
        }
    }
}

static void drawClouds() {
    if (gRotate != 0)
    {
        rotation[0] += 0.100f * timedelta;
        rotation[1] += 0.102f * timedelta;
        rotation[2] += 0.106f * timedelta;
        rotation[3] += 0.114f * timedelta;
        rotation[4] += 0.123f * timedelta;
    }

    int mask = gTextureMask;
    if (mask & 1) {
        xshift[0] += 0.00100f * timedelta;
    }
    if (mask & 2) {
        xshift[1] += 0.00106f * timedelta;
    }
    if (mask & 4) {
        xshift[2] += 0.00114f * timedelta;
    }
    if (mask & 8) {
        xshift[3] += 0.00118f * timedelta;
    }
    if (mask & 16) {
        xshift[4] += 0.00127f * timedelta;
    }

    update();

    float z = 0;
    rsgDrawQuad(
        -1.0f, -1.0f, z,
         1.0f, -1.0f, z,
         1.0f,  1.0f, z,
        -1.0f,  1.0f, z
    );

    // Make sure the texture coordinates don't continuously increase
    int i;
    for(i = 0; i < 5; i++) {
        if (xshift[i] > 1.f) {
            xshift[i] -= floor(xshift[i]);
        }
    }
    // Make sure the rotation angles don't continuously increase
    for(i = 0; i < 5; i++) {
        if (rotation[i] > 360.f) {
            float multiplier = floor(rotation[i]/360.f);
            rotation[i] -= 360.f * multiplier;
        }
    }
}

static int premul(int rgb, int a) {
    int r = (rgb >> 16) * a + 1;
    r = (r + (r >> 8)) >> 8;
    int g = ((rgb >> 8) & 0xff) * a + 1;
    g = (g + (g >> 8)) >> 8;
    int b = (rgb & 0xff) * a + 1;
    b = (b + (b >> 8)) >> 8;
    return r << 16 | g << 8 | b;
}


static void makeTexture(int *src, int *dst, rs_allocation rsid) {

    int x;
    int y;
    int pm = gPreMul;

    if (gProcessTextureMode == 1) {
        int lowcol = gLowCol;
        int highcol = gHighCol;

        for (y=0;y<256;y++) {
            for (x=0;x<256;x++) {
                int pix = src[y*256+x];
                int lum = pix & 0x00ff;
                int newpix;
                if (lum < 128) {
                    newpix = lowcol;
                    int newalpha = 255 - (lum * 2);
                    newalpha /= alphafactor;
                    if (pm) newpix = premul(newpix, newalpha);
                    newpix = newpix | (newalpha << 24);
                } else {
                    newpix = highcol;
                    int newalpha = (lum - 128) * 2;
                    newalpha /= alphafactor;
                    if (pm) newpix = premul(newpix, newalpha);
                    newpix = newpix | (newalpha << 24);
                }
                // have ARGB, need ABGR
                newpix = (newpix & 0xff00ff00) | ((newpix & 0xff) << 16) | ((newpix >> 16) & 0xff);
                dst[y*256+x] = newpix;
            }
        }
        alphafactor *= gAlphaMul;
    } else if (gProcessTextureMode == 2) {
        int lowcol = gLowCol;
        int highcol = gHighCol;
        float scale = 255.f / (255.f - lowcol);

        for (y=0;y<256;y++) {
            for (x=0;x<256;x++) {
                int pix = src[y*256+x];
                int alpha = pix & 0x00ff;
                if (alpha < lowcol) {
                    alpha = 0;
                } else {
                    alpha = (alpha - lowcol) * scale;
                }
                alpha /= alphafactor;
                int newpix = highcol;
                if (pm) newpix = premul(newpix, alpha);
                newpix = newpix | (alpha << 24);
                // have ARGB, need ABGR
                newpix = (newpix & 0xff00ff00) | ((newpix & 0xff) << 16) | ((newpix >> 16) & 0xff);
                dst[y*256+x] = newpix;
            }
        }
        alphafactor *= gAlphaMul;
    } else if (gProcessTextureMode == 3) {
        int lowcol = gLowCol;
        int highcol = gHighCol;
        float scale = 255.f / (255.f - lowcol);

        for (y=0;y<256;y++) {
            for (x=0;x<256;x++) {
                int pix = src[y*256+x];
                int lum = pix & 0x00ff;
                int newpix;
                if (lum < 128) lum *= 2;
                else lum = (255 - (lum - 128) * 2);
                if (lum < 128) {
                    newpix = lowcol;
                    int newalpha = 255 - (lum * 2);
                    newalpha /= alphafactor;
                    if (pm) newpix = premul(newpix, newalpha);
                    newpix = newpix | (newalpha << 24);
                } else {
                    newpix = highcol;
                    int newalpha = (lum - 128) * 2;
                    newalpha /= alphafactor;
                    if (pm) newpix = premul(newpix, newalpha);
                    newpix = newpix | (newalpha << 24);
                }
                // have ARGB, need ABGR
                newpix = (newpix & 0xff00ff00) | ((newpix & 0xff) << 16) | ((newpix >> 16) & 0xff);
                dst[y*256+x] = newpix;
            }
        }
        alphafactor *= gAlphaMul;
    } else {
        for (y=0;y<256;y++) {
            for (x=0;x<256;x++) {
                int rgb = *src++;
                int a = (rgb >> 24) & 0xff;
                rgb &= 0x00ffffff;
                rgb = premul(rgb, a);
                int newpix = (a << 24) | rgb;
                newpix = (newpix & 0xff00ff00) | ((newpix & 0xff) << 16) | ((newpix >> 16) & 0xff);
                *dst++ = newpix;
            }
        }
    }

    rsgAllocationSyncAll(rsid);
}

static void makeTextures() {
    alphafactor = 1.f;
    makeTexture((int*)gNoisesrc1, (int*)gNoisedst1, gTnoise1);
    makeTexture((int*)gNoisesrc2, (int*)gNoisedst2, gTnoise2);
    makeTexture((int*)gNoisesrc3, (int*)gNoisedst3, gTnoise3);
    makeTexture((int*)gNoisesrc4, (int*)gNoisedst4, gTnoise4);
    makeTexture((int*)gNoisesrc5, (int*)gNoisedst5, gTnoise5);
}

void init() {
    for (int i=0;i<5;i++) {
        xshift[i] = 0.f;
        rotation[i] = 360.f * i / 5.f;
    }

    scale[0] = 4.0f; // changed below based on preset
    scale[1] = 3.0f;
    scale[2] = 3.4f;
    scale[3] = 3.8f;
    scale[4] = 4.2f;

    currentpreset = -1;
    lastuptime = (int)rsUptimeMillis();
    timedelta = 0;
}


int root(void) {
    int i;

    int now = (int)rsUptimeMillis();
    timedelta = ((float)(now - lastuptime)) / 44.f;
    lastuptime = now;
    if (timedelta > 3) {
        // Limit the step adjustment factor to 3, so we don't get a sudden jump
        // after coming back from sleep.
        timedelta = 3;
    }

    i = gPreset;
    if (i != currentpreset) {
        currentpreset = i;
        clearColor.x = ((float)((gBackCol >> 16)  & 0xff)) / 255.0f;
        clearColor.y = ((float)((gBackCol >> 8)  & 0xff)) / 255.0f;
        clearColor.z = ((float)(gBackCol & 0xff)) / 255.0f;
        makeTextures();
    }

    if (gTextureSwap != 0) {
        scale[0] = .25f;
    } else {
        scale[0] = 4.f;
    }
    drawClouds();

    return 55;
}