premultiplied alpha for grass

git-svn-id: https://sauerbraten.svn.sourceforge.net/svnroot/sauerbraten/src@3315 ac1f7847-fce6-4368-a212-70e9bdee79d4
sjuxax · Nov 19, 2010 · 4c19f78 · 4c19f78
1 parent 598f023
commit 4c19f78
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Showing 3 changed files with 40 additions and 11 deletions.
diff --git a/engine/grass.cpp b/engine/grass.cpp
@@ -141,9 +141,9 @@ static void gengrassquads(grassgroup *&group, const grasswedge &w, const grasstr
               tc1 = tc.dot(p1) + offset, tc2 = tc.dot(p2) + offset,
               lm1u = g.tcu.dot(p1), lm1v = g.tcv.dot(p1),
               lm2u = g.tcu.dot(p2), lm2v = g.tcv.dot(p2),
-              fade = dist > taperdist ? (grassdist - dist)*taperscale : 1,
+              fade = dist > taperdist ? (grassdist - dist)*taperscale*grassalpha : grassalpha,
               height = grassheight * fade;
-        uchar color[4] = { grasscolor.x, grasscolor.y, grasscolor.z, uchar(fade*grassalpha*255) };
+        uchar color[4] = { grasscolor.x, grasscolor.y, grasscolor.z, uchar(fade*255) };
 
         #define GRASSVERT(n, tcv, modify) { \
             grassvert &gv = grassverts.add(); \
@@ -229,7 +229,7 @@ void rendergrass()
 
     glDisable(GL_CULL_FACE);
     glEnable(GL_BLEND);
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    glBlendFunc(renderpath==R_FIXEDFUNCTION ? GL_SRC_ALPHA : GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
     glDepthMask(GL_FALSE);
 
     SETSHADER(grass);

diff --git a/engine/shader.cpp b/engine/shader.cpp
@@ -1395,17 +1395,17 @@ static void genfogshader(vector<char> &vsbuf, vector<char> &psbuf, const char *v
     const char *psend = strrchr(ps, '}');
     if(psend)
     {
-        static const int rgbalen = strlen("#pragma CUBE2_fogrgba");
-        bool rgba = pspragma && !strncmp(pspragma, "#pragma CUBE2_fogrgba", rgbalen);
         psbuf.put(ps, psend - ps);
         const char *psdef = "\n#define FOG_COLOR ";
-        const char *psfog = rgba ?
-            "\ngl_FragColor = mix((FOG_COLOR), gl_FragColor, clamp((gl_Fog.end - gl_FogFragCoord) * gl_Fog.scale, 0.0, 1.0));\n" :
-            "\ngl_FragColor.rgb = mix((FOG_COLOR).rgb, gl_FragColor.rgb, clamp((gl_Fog.end - gl_FogFragCoord) * gl_Fog.scale, 0.0, 1.0));\n";
+        const char *psfog = 
+            pspragma && !strncmp(pspragma+pragmalen, "rgba", 4) ? 
+                "\ngl_FragColor = mix((FOG_COLOR), gl_FragColor, clamp((gl_Fog.end - gl_FogFragCoord) * gl_Fog.scale, 0.0, 1.0));\n" :
+                "\ngl_FragColor.rgb = mix((FOG_COLOR).rgb, gl_FragColor.rgb, clamp((gl_Fog.end - gl_FogFragCoord) * gl_Fog.scale, 0.0, 1.0));\n";
         int clen = 0;
         if(pspragma)
         {
-            pspragma += rgba ? rgbalen : pragmalen;
+            pspragma += pragmalen;
+            while (isalpha(*pspragma)) pspragma++;
             while(*pspragma && !isspace(*pspragma)) pspragma++;
             pspragma += strspn(pspragma, " \t\v\f");
             clen = strcspn(pspragma, "\r\n");

diff --git a/engine/texture.cpp b/engine/texture.cpp
@@ -254,6 +254,26 @@ void texgrey(ImageData &s)
     s.replace(d);
 }
 
+void texpremul(ImageData &s)
+{
+    switch(s.bpp)
+    {
+        case 2: 
+            writetex(s, 
+                dst[0] = uchar((uint(dst[0])*uint(dst[1]))/255);
+            ); 
+            break;
+        case 4: 
+            writetex(s,
+                uint alpha = dst[3];
+                dst[0] = uchar((uint(dst[0])*alpha)/255);
+                dst[1] = uchar((uint(dst[1])*alpha)/255);
+                dst[2] = uchar((uint(dst[2])*alpha)/255);
+            );
+            break;
+    }
+}
+
 VAR(hwtexsize, 1, 0, 0);
 VAR(hwcubetexsize, 1, 0, 0);
 VAR(hwmaxaniso, 1, 0, 0);
@@ -1014,7 +1034,7 @@ static bool texturedata(ImageData &d, const char *tname, Slot::Tex *tex = NULL,
         else if(!strncmp(cmd, "ffmask", len)) 
         {
             texffmask(d, atof(arg[0]), atof(arg[1]));
-            if(!d.data) return true;
+            if(!d.data) break;
         }
         else if(!strncmp(cmd, "normal", len)) 
         {
@@ -1033,6 +1053,7 @@ static bool texturedata(ImageData &d, const char *tname, Slot::Tex *tex = NULL,
             int emphasis = atoi(arg[0]), repeat = atoi(arg[1]);
             texblur(d, emphasis > 0 ? clamp(emphasis, 1, 2) : 1, repeat > 0 ? repeat : 1);
         }
+        else if(!strncmp(cmd, "premul", len)) texpremul(d);
         else if(!strncmp(cmd, "compress", len) || !strncmp(cmd, "dds", len)) 
         { 
             int scale = atoi(arg[0]);
@@ -1050,6 +1071,10 @@ static bool texturedata(ImageData &d, const char *tname, Slot::Tex *tex = NULL,
             if(h <= 0 || h > (1<<12)) h = w;
             if(d.w > w || d.h > h) scaleimage(d, w, h);
         }
+        else if(!strncmp(cmd, "ffskip", len))
+        {
+            if(renderpath==R_FIXEDFUNCTION) break;
+        }
     }
 
     return true;
@@ -1517,7 +1542,7 @@ void autograss(char *name)
     if(slots.empty()) return;
     Slot &s = *slots.last();
     DELETEA(s.autograss);
-    s.autograss = name[0] ? newstring(makerelpath("packages", name)) : NULL;
+    s.autograss = name[0] ? newstring(makerelpath("packages", name, NULL, "<ffskip><premul>")) : NULL;
 }
 COMMAND(autograss, "s");
 
@@ -2376,7 +2401,9 @@ enum
     DDSCAPS2_CUBEMAP_NEGATIVEZ = 0x00008000, 
     DDSCAPS2_VOLUME            = 0x00200000,
     FOURCC_DXT1                = 0x31545844,
+    FOURCC_DXT2                = 0x32545844,
     FOURCC_DXT3                = 0x33545844,
+    FOURCC_DXT4                = 0x34545844,
     FOURCC_DXT5                = 0x35545844
 
 };
@@ -2423,7 +2450,9 @@ bool loaddds(const char *filename, ImageData &image)
         switch(d.ddpfPixelFormat.dwFourCC)
         {
             case FOURCC_DXT1: format = d.ddpfPixelFormat.dwFlags & DDPF_ALPHAPIXELS ? GL_COMPRESSED_RGBA_S3TC_DXT1_EXT : GL_COMPRESSED_RGB_S3TC_DXT1_EXT; break;
+            case FOURCC_DXT2:
             case FOURCC_DXT3: format = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT; break;
+            case FOURCC_DXT4:
             case FOURCC_DXT5: format = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT; break;
         }        
     }