1 files changed, 143 insertions, 0 deletions

diff --git a/apps/plugins/sdl/progs/wolf3d/wl_shade.c b/apps/plugins/sdl/progs/wolf3d/wl_shade.c
new file mode 100644
index 0000000000..3f1d5a7b3f
--- /dev/null
+++ b/apps/plugins/sdl/progs/wolf3d/wl_shade.c
@@ -0,0 +1,143 @@
+#include "version.h"
+
+#ifdef USE_SHADING
+#include "wl_def.h"
+#include "wl_shade.h"
+
+typedef struct {
+    uint8_t destRed, destGreen, destBlue;   // values between 0 and 255
+    uint8_t fogStrength;
+} shadedef_t;
+
+shadedef_t shadeDefs[] = {
+    {   0,   0,   0, LSHADE_NOSHADING },
+    {   0,   0,   0, LSHADE_NORMAL },
+    {   0,   0,   0, LSHADE_FOG },
+    {  40,  40,  40, LSHADE_NORMAL },
+    {  60,  60,  60, LSHADE_FOG }
+};
+
+uint8_t shadetable[SHADE_COUNT][256];
+int LSHADE_flag;
+
+#ifdef USE_FEATUREFLAGS
+
+// The lower 8-bit of the upper left tile of every map determine
+// the used shading definition of shadeDefs.
+static int GetShadeDefID()
+{
+    int shadeID = ffDataTopLeft & 0x00ff;
+    assert(shadeID >= 0 && shadeID < lengthof(shadeDefs));
+    return shadeID;
+}
+
+#else
+
+static int GetShadeDefID()
+{
+    int shadeID;
+    switch(gamestate.episode * 10 + mapon)
+    {
+        case  0: shadeID = 4; break;
+        case  1:
+        case  2:
+        case  6: shadeID = 1; break;
+        case  3: shadeID = 0; break;
+        case  5: shadeID = 2; break;
+        default: shadeID = 3; break;
+    }
+    assert(shadeID >= 0 && shadeID < lengthof(shadeDefs));
+    return shadeID;
+}
+
+#endif
+
+
+// Returns the palette index of the nearest matching color of the
+// given RGB color in given palette
+byte GetColor(byte red, byte green, byte blue, SDL_Color *palette)
+{
+    byte mincol = 0;
+    double mindist = 200000.F, curdist, DRed, DGreen, DBlue;
+
+    SDL_Color *palPtr = palette;
+
+    for(int col = 0; col < 256; col++, palPtr++)
+    {
+        DRed   = (double) (red   - palPtr->r);
+        DGreen = (double) (green - palPtr->g);
+        DBlue  = (double) (blue  - palPtr->b);
+        curdist = DRed * DRed + DGreen * DGreen + DBlue * DBlue;
+        if(curdist < mindist)
+        {
+            mindist = curdist;
+            mincol = (byte) col;
+        }
+    }
+    return mincol;
+}
+
+// Fade all colors in 32 steps down to the destination-RGB
+// (use gray for fogging, black for standard shading)
+void GenerateShadeTable(byte destRed, byte destGreen, byte destBlue,
+                        SDL_Color *palette, int fog)
+{
+    double curRed, curGreen, curBlue, redStep, greenStep, blueStep;
+    SDL_Color *palPtr = palette;
+
+    // Set the fog-flag
+    LSHADE_flag=fog;
+
+    // Color loop
+    for(int i = 0; i < 256; i++, palPtr++)
+    {
+        // Get original palette color
+        curRed   = palPtr->r;
+        curGreen = palPtr->g;
+        curBlue  = palPtr->b;
+
+        // Calculate increment per step
+        redStep   = ((double) destRed   - curRed)   / (SHADE_COUNT + 8);
+        greenStep = ((double) destGreen - curGreen) / (SHADE_COUNT + 8);
+        blueStep  = ((double) destBlue  - curBlue)  / (SHADE_COUNT + 8);
+
+        // Calc color for each shade of the current color
+        for (int shade = 0; shade < SHADE_COUNT; shade++)
+        {
+            shadetable[shade][i] = GetColor((byte) curRed, (byte) curGreen, (byte) curBlue, palette);
+
+            // Inc to next shade
+            curRed   += redStep;
+            curGreen += greenStep;
+            curBlue  += blueStep;
+        }
+    }
+}
+
+void NoShading()
+{
+    for(int shade = 0; shade < SHADE_COUNT; shade++)
+        for(int i = 0; i < 256; i++)
+            shadetable[shade][i] = i;
+}
+
+void InitLevelShadeTable()
+{
+    shadedef_t *shadeDef = &shadeDefs[GetShadeDefID()];
+    if(shadeDef->fogStrength == LSHADE_NOSHADING)
+        NoShading();
+    else
+        GenerateShadeTable(shadeDef->destRed, shadeDef->destGreen, shadeDef->destBlue, gamepal, shadeDef->fogStrength);
+}
+
+int GetShade(int scale)
+{
+    int shade = (scale >> 1) / (((viewwidth * 3) >> 8) + 1 + LSHADE_flag);  // TODO: reconsider this...
+    if(shade > 32) shade = 32;
+    else if(shade < 1) shade = 1;
+    shade = 32 - shade;
+
+    return shade;
+}
+
+#endif