1 files changed, 259 insertions, 0 deletions

diff --git a/apps/plugins/sdl/progs/wolf3d/wl_cloudsky.c b/apps/plugins/sdl/progs/wolf3d/wl_cloudsky.c
new file mode 100644
index 0000000000..a2f58cd8a6
--- /dev/null
+++ b/apps/plugins/sdl/progs/wolf3d/wl_cloudsky.c
@@ -0,0 +1,259 @@
+#include "version.h"
+
+#ifdef USE_CLOUDSKY
+
+#include "wl_def.h"
+#include "wl_cloudsky.h"
+
+// Each colormap defines a number of colors which should be mapped from
+// the skytable. The according colormapentry_t array defines how these colors should
+// be mapped to the wolfenstein palette. The first int of each entry defines
+// how many colors are grouped to this entry and the absolute value of the
+// second int sets the starting palette index for this pair. If this value is
+// negative the index will be decremented for every color, if it's positive
+// it will be incremented.
+//
+// Example colormap:
+//   colormapentry_t colmapents_1[] = { { 6, -10 }, { 2, 40 } };
+//   colormap_t colorMaps[] = {
+//      { 8, colmapents_1 }
+//   };
+//
+//   The colormap 0 consists of 8 colors. The first color group consists of 6
+//   colors and starts descending at palette index 10: 10, 9, 8, 7, 6, 5
+//   The second color group consists of 2 colors and starts ascending at
+//   index 40: 40, 41
+//   There's no other color group because all colors of this colormap are
+//   already used (6+2=8)
+//
+// Warning: Always make sure that the sum of the amount of the colors in all
+//          color groups is the number of colors used for your colormap!
+
+colormapentry_t colmapents_1[] = { { 16, -31 }, { 16, 136 } };
+colormapentry_t colmapents_2[] = { { 16, -31 } };
+
+colormap_t colorMaps[] = {
+    { 32, colmapents_1 },
+    { 16, colmapents_2 }
+};
+
+const int numColorMaps = lengthof(colorMaps);
+
+// The sky definitions which can be selected as defined by GetCloudSkyDefID() in wl_def.h
+// You can use <TAB>+Z in debug mode to find out suitable values for seed and colorMapIndex
+// Each entry consists of seed, speed, angle and colorMapIndex
+cloudsky_t cloudSkys[] = {
+    { 626,   800,  20,  0 },
+    { 1234,  650,  60,  1 },
+    { 0,     700,  120, 0 },
+    { 0,     0,    0,   0 },
+    { 11243, 750,  310, 0 },
+    { 32141, 750,  87,  0 },
+    { 12124, 750,  64,  0 },
+    { 55543, 500,  240, 0 },
+    { 65535, 200,  54,  1 },
+    { 4,     1200, 290, 0 },
+};
+
+byte skyc[65536L];
+
+long cloudx = 0, cloudy = 0;
+cloudsky_t *curSky = NULL;
+
+#ifdef USE_FEATUREFLAGS
+
+// The lower left tile of every map determines the used cloud sky definition from cloudSkys.
+static int GetCloudSkyDefID()
+{
+    int skyID = ffDataBottomLeft;
+    assert(skyID >= 0 && skyID < lengthof(cloudSkys));
+    return skyID;
+}
+
+#else
+
+static int GetCloudSkyDefID()
+{
+    int skyID;
+    switch(gamestate.episode * 10 + mapon)
+    {
+        case  0: skyID =  0; break;
+        case  1: skyID =  1; break;
+        case  2: skyID =  2; break;
+        case  3: skyID =  3; break;
+        case  4: skyID =  4; break;
+        case  5: skyID =  5; break;
+        case  6: skyID =  6; break;
+        case  7: skyID =  7; break;
+        case  8: skyID =  8; break;
+        case  9: skyID =  9; break;
+        default: skyID =  9; break;
+    }
+    assert(skyID >= 0 && skyID < lengthof(cloudSkys));
+    return skyID;
+}
+
+#endif
+
+void SplitS(unsigned size,unsigned x1,unsigned y1,unsigned x2,unsigned y2)
+{
+   if(size==1) return;
+   if(!skyc[((x1+size/2)*256+y1)])
+   {
+      skyc[((x1+size/2)*256+y1)]=(byte)(((int)skyc[(x1*256+y1)]
+            +(int)skyc[((x2&0xff)*256+y1)])/2)+rand()%(size*2)-size;
+      if(!skyc[((x1+size/2)*256+y1)]) skyc[((x1+size/2)*256+y1)]=1;
+   }
+   if(!skyc[((x1+size/2)*256+(y2&0xff))])
+   {
+      skyc[((x1+size/2)*256+(y2&0xff))]=(byte)(((int)skyc[(x1*256+(y2&0xff))]
+            +(int)skyc[((x2&0xff)*256+(y2&0xff))])/2)+rand()%(size*2)-size;
+      if(!skyc[((x1+size/2)*256+(y2&0xff))])
+         skyc[((x1+size/2)*256+(y2&0xff))]=1;
+   }
+   if(!skyc[(x1*256+y1+size/2)])
+   {
+      skyc[(x1*256+y1+size/2)]=(byte)(((int)skyc[(x1*256+y1)]
+            +(int)skyc[(x1*256+(y2&0xff))])/2)+rand()%(size*2)-size;
+      if(!skyc[(x1*256+y1+size/2)]) skyc[(x1*256+y1+size/2)]=1;
+   }
+   if(!skyc[((x2&0xff)*256+y1+size/2)])
+   {
+      skyc[((x2&0xff)*256+y1+size/2)]=(byte)(((int)skyc[((x2&0xff)*256+y1)]
+            +(int)skyc[((x2&0xff)*256+(y2&0xff))])/2)+rand()%(size*2)-size;
+      if(!skyc[((x2&0xff)*256+y1+size/2)]) skyc[((x2&0xff)*256+y1+size/2)]=1;
+   }
+
+   skyc[((x1+size/2)*256+y1+size/2)]=(byte)(((int)skyc[(x1*256+y1)]
+         +(int)skyc[((x2&0xff)*256+y1)]+(int)skyc[(x1*256+(y2&0xff))]
+         +(int)skyc[((x2&0xff)*256+(y2&0xff))])/4)+rand()%(size*2)-size;
+
+   SplitS(size/2,x1,y1+size/2,x1+size/2,y2);
+   SplitS(size/2,x1+size/2,y1,x2,y1+size/2);
+   SplitS(size/2,x1+size/2,y1+size/2,x2,y2);
+   SplitS(size/2,x1,y1,x1+size/2,y1+size/2);
+}
+
+void InitSky()
+{
+    unsigned cloudskyid = GetCloudSkyDefID();
+    if(cloudskyid >= lengthof(cloudSkys))
+        Quit("Illegal cloud sky id: %u", cloudskyid);
+    curSky = &cloudSkys[cloudskyid];
+
+    memset(skyc, 0, sizeof(skyc));
+    // funny water texture if used instead of memset ;D
+    // for(int i = 0; i < 65536; i++)
+    //     skyc[i] = rand() % 32 * 8;
+
+    srand(curSky->seed);
+    skyc[0] = rand() % 256;
+    SplitS(256, 0, 0, 256, 256);
+
+    // Smooth the clouds a bit
+    for(int k = 0; k < 2; k++)
+    {
+        for(int i = 0; i < 256; i++)
+        {
+            for(int j = 0; j < 256; j++)
+            {
+                int32_t val = -skyc[j * 256 + i];
+                for(int m = 0; m < 3; m++)
+                {
+                    for(int n = 0; n < 3; n++)
+                    {
+                        val += skyc[((j + n - 1) & 0xff) * 256 + ((i + m - 1) & 0xff)];
+                    }
+                }
+                skyc[j * 256 + i] = (byte)(val >> 3);
+            }
+        }
+    }
+
+    // the following commented line could be useful, if you're trying to
+    // create a new color map. This will display your current color map
+    // in one (of course repeating) stripe of the sky
+
+    // for(int i = 0; i < 256; i++)
+    //     skyc[i] = skyc[i + 256] = skyc[i + 512] = i;
+
+    if(curSky->colorMapIndex >= lengthof(colorMaps))
+        Quit("Illegal colorMapIndex for cloud sky def %u: %u", cloudskyid, curSky->colorMapIndex);
+
+    colormap_t *curMap = &colorMaps[curSky->colorMapIndex];
+    int numColors = curMap->numColors;
+    byte colormap[256];
+    colormapentry_t *curEntry = curMap->entries;
+    for(int calcedCols = 0; calcedCols < numColors; curEntry++)
+    {
+        if(curEntry->startAndDir < 0)
+        {
+            for(int i = 0, ind = -curEntry->startAndDir; i < curEntry->length; i++, ind--)
+                colormap[calcedCols++] = ind;
+        }
+        else
+        {
+            for(int i = 0, ind = curEntry->startAndDir; i < curEntry->length; i++, ind++)
+                colormap[calcedCols++] = ind;
+        }
+    }
+
+    for(int i = 0; i < 256; i++)
+    {
+        for(int j = 0; j < 256; j++)
+        {
+            skyc[i * 256 + j] = colormap[skyc[i * 256 + j] * numColors / 256];
+        }
+    }
+}
+
+// Based on Textured Floor and Ceiling by DarkOne
+void DrawClouds(byte *vbuf, unsigned vbufPitch, int min_wallheight)
+{
+    // Move clouds
+    fixed moveDist = tics * curSky->speed;
+    cloudx += FixedMul(moveDist,sintable[curSky->angle]);
+    cloudy -= FixedMul(moveDist,costable[curSky->angle]);
+
+    // Draw them
+    int y0, halfheight;
+    unsigned top_offset0;
+    fixed dist;                                // distance to row projection
+    fixed tex_step;                            // global step per one screen pixel
+    fixed gu, gv, du, dv;                      // global texture coordinates
+    int u, v;                                  // local texture coordinates
+
+    // ------ * prepare * --------
+    halfheight = viewheight >> 1;
+    y0 = min_wallheight >> 3;                  // starting y value
+    if(y0 > halfheight)
+        return;                                // view obscured by walls
+    if(!y0) y0 = 1;                            // don't let division by zero
+    top_offset0 = vbufPitch * (halfheight - y0 - 1);
+
+    // draw horizontal lines
+    for(int y = y0, top_offset = top_offset0; y < halfheight; y++, top_offset -= vbufPitch)
+    {
+        dist = (heightnumerator / y) << 8;
+        gu =  viewx + FixedMul(dist, viewcos) + cloudx;
+        gv = -viewy + FixedMul(dist, viewsin) + cloudy;
+        tex_step = (dist << 8) / viewwidth / 175;
+        du =  FixedMul(tex_step, viewsin);
+        dv = -FixedMul(tex_step, viewcos);
+        gu -= (viewwidth >> 1)*du;
+        gv -= (viewwidth >> 1)*dv;          // starting point (leftmost)
+        for(int x = 0, top_add = top_offset; x < viewwidth; x++, top_add++)
+        {
+            if(wallheight[x] >> 3 <= y)
+            {
+                u = (gu >> 13) & 255;
+                v = (gv >> 13) & 255;
+                vbuf[top_add] = skyc[((255 - u) << 8) + 255 - v];
+            }
+            gu += du;
+            gv += dv;
+        }
+    }
+}
+
+#endif