CON: in rotatespritea and screentext, if alpha < 0, make -alpha denote blend.

For convenience, orientation gets bit 1 (translucency) set automatically.
Again, test/screentext.con is updated to show off this functionality (the
code there assumes that additive blending tables are loaded at blend
numbers 101 -- 132).

BUILD_LUNATIC.

git-svn-id: https://svn.eduke32.com/eduke32@4428 1a8010ca-5511-0410-912e-c29ae57300e0

polymer/eduke32/source/game.c

@@ -758,7 +758,7 @@ void G_AddCoordsFromRotation(vec2_t *coords, const vec2_t *unitDirection, const
 // screentext
 vec2_t G_ScreenText(const int32_t font,
                     int32_t x, int32_t y, const int32_t z, const int32_t blockangle, const int32_t charangle,
-                    const char *str, const int32_t shade, int32_t pal, int32_t o, const int32_t alpha,
+                    const char *str, const int32_t shade, int32_t pal, int32_t o, int32_t alpha,
                     int32_t xspace, int32_t yline, int32_t xbetween, int32_t ybetween, const int32_t f,
                     const int32_t x1, const int32_t y1, const int32_t x2, const int32_t y2)
 {
@@ -769,7 +769,7 @@ vec2_t G_ScreenText(const int32_t font,
     const vec2_t Xdirection = { sintable[(blockangle+512)&2047], sintable[blockangle&2047], };
     const vec2_t Ydirection = { sintable[(blockangle+1024)&2047], sintable[(blockangle+512)&2047], };
 
-    int32_t tile;
+    int32_t blendidx=0, tile;
     char t;
 
     // set the start and end points depending on direction
@@ -781,6 +781,8 @@ vec2_t G_ScreenText(const int32_t font,
     if (str == NULL)
         return size;
 
+    NEG_ALPHA_TO_BLEND(alpha, blendidx, o);
+
     end = (f & TEXT_BACKWARDS) ? str-1 : Bstrchr(str,'\0');
     text = (f & TEXT_BACKWARDS) ? Bstrchr(str,'\0')-1 : str;
 
@@ -929,7 +931,7 @@ vec2_t G_ScreenText(const int32_t font,
                 G_AddCoordsFromRotation(&location, &Xdirection, pos.x);
                 G_AddCoordsFromRotation(&location, &Ydirection, pos.y);
 
-                rotatesprite_(location.x, location.y, z, angle, tile, shade, pal, orientation, alpha, 0, x1, y1, x2, y2);
+                rotatesprite_(location.x, location.y, z, angle, tile, shade, pal, orientation, alpha, blendidx, x1, y1, x2, y2);
 
                 break;
             }

polymer/eduke32/source/game.h

@@ -372,9 +372,13 @@ extern char* G_GetSubString(const char *text, const char *end, const int32_t ite
 extern int32_t G_GetStringTile(int32_t font, char *t, int32_t f);
 extern vec2_t G_ScreenTextSize(const int32_t font, int32_t x, int32_t y, const int32_t z, const int32_t blockangle, const char *str, const int32_t o, int32_t xspace, int32_t yline, int32_t xbetween, int32_t ybetween, const int32_t f, const int32_t x1, const int32_t y1, const int32_t x2, const int32_t y2);
 extern void G_AddCoordsFromRotation(vec2_t *coords, const vec2_t *unitDirection, const int32_t magnitude);
-extern vec2_t G_ScreenText(const int32_t font, int32_t x, int32_t y, const int32_t z, const int32_t blockangle, const int32_t charangle, const char *str, const int32_t shade, int32_t pal, int32_t o, const int32_t alpha, int32_t xspace, int32_t yline, int32_t xbetween, int32_t ybetween, const int32_t f, int32_t x1, int32_t y1, int32_t x2, int32_t y2);
+extern vec2_t G_ScreenText(const int32_t font, int32_t x, int32_t y, const int32_t z, const int32_t blockangle, const int32_t charangle, const char *str, const int32_t shade, int32_t pal, int32_t o, int32_t alpha, int32_t xspace, int32_t yline, int32_t xbetween, int32_t ybetween, const int32_t f, int32_t x1, int32_t y1, int32_t x2, int32_t y2);
 extern vec2_t G_ScreenTextShadow(int32_t sx, int32_t sy, const int32_t font, int32_t x, int32_t y, const int32_t z, const int32_t blockangle, const int32_t charangle, const char *str, const int32_t shade, int32_t pal, int32_t o, const int32_t alpha, int32_t xspace, int32_t yline, int32_t xbetween, int32_t ybetween, const int32_t f, int32_t x1, int32_t y1, int32_t x2, int32_t y2);
 
+#define NEG_ALPHA_TO_BLEND(alpha, blend, orientation) do { \
+    if (alpha < 0) { blend = -alpha; alpha = 0; orientation |= RS_TRANS1; } \
+} while (0)
+
 int32_t app_main(int32_t argc,const char **argv);
 void fadepal(int32_t r,int32_t g,int32_t b,int32_t start,int32_t end,int32_t step);
 //void fadepaltile(int32_t r,int32_t g,int32_t b,int32_t start,int32_t end,int32_t step,int32_t tile);

polymer/eduke32/source/gameexec.c

@@ -2741,6 +2741,8 @@ nullquote:
                 int32_t x1=Gv_GetVarX(*insptr++),  y1=Gv_GetVarX(*insptr++);
                 int32_t x2=Gv_GetVarX(*insptr++),  y2=Gv_GetVarX(*insptr++);
 
+                int32_t blendidx = 0;
+
                 if (tw != CON_ROTATESPRITE16 && !(orientation&ROTATESPRITE_FULL16))
                 {
                     x<<=16;
@@ -2761,7 +2763,9 @@ nullquote:
 
                 orientation &= (ROTATESPRITE_MAX-1);
 
-                rotatesprite_(x,y,z,a,tilenum,shade,pal,2|orientation,alpha,0,x1,y1,x2,y2);
+                NEG_ALPHA_TO_BLEND(alpha, blendidx, orientation);
+
+                rotatesprite_(x,y,z,a,tilenum,shade,pal,2|orientation,alpha,blendidx,x1,y1,x2,y2);
                 continue;
             }
 

polymer/eduke32/source/lunatic/control.lua

@@ -408,8 +408,14 @@ function _rotspr(x, y, zoom, ang, tilenum, shade, pal, orientation,
         error(format("invalid coordinates (%.03f, %.03f)", x, y), 2)
     end
 
+    local blendidx = 0
+    if (alpha < 0) then
+        blendidx = -alpha
+        alpha = 0
+    end
+
     ffiC.rotatesprite_(x, y, zoom, ang, tilenum, shade, pal, bor(2,orientation),
-                       alpha, 0, cx1, cy1, cx2, cy2)
+                       alpha, blendidx, cx1, cy1, cx2, cy2)
 end
 
 -- The external legacy tile drawing function for Lunatic.

polymer/eduke32/source/lunatic/defs.ilua

@@ -699,7 +699,7 @@ typedef struct {
 } vec2_t;
 vec2_t G_ScreenText(const int32_t font,
                     int32_t x, int32_t y, const int32_t z, const int32_t blockangle, const int32_t charangle,
-                    const char *str, const int32_t shade, int32_t pal, int32_t o, const int32_t alpha,
+                    const char *str, const int32_t shade, int32_t pal, int32_t o, int32_t alpha,
                     int32_t xspace, int32_t yline, int32_t xbetween, int32_t ybetween, const int32_t f,
                     const int32_t x1, const int32_t y1, const int32_t x2, const int32_t y2);
 vec2_t G_ScreenTextSize(const int32_t font,

polymer/eduke32/source/lunatic/test/screentext.con

@@ -62,6 +62,7 @@ gamevar x2 0 0
 gamevar y2 0 0
 
 gamevar temp 0 0
+gamevar doaddtvblend 0 0
 
 state resetbounds
     setvarvar x1 windowx1
@@ -178,14 +179,32 @@ onevent EVENT_DISPLAYREST
     xorvar f TEXT_UPPERCASE
     state increment_line
 
-    // Calculate periodically cycling alpha value
+    // Calculate periodically cycling alpha value. PERIODIC_ALPHA.
     setvarvar temp totalclock
     shiftvarl temp 2
 
     sin alpha temp   // alpha is now in [-2^14 .. 2^14]
     shiftvarr alpha 7  // [-2^7 .. 2^7]
     addvar alpha 128  // [0 .. 256]
-    ifvarg alpha 255 setvar alpha 255
+    ifvarg alpha 254 { setvar alpha 255 setvar doaddtvblend 1 }
+    else ifvarl alpha 2 { setvar doaddtvblend 0 }
+
+    ifvare doaddtvblend 1
+    {
+        shiftvarr alpha 2  // [0 63]
+
+        ifvarg alpha 31
+        {
+            setvar temp 63
+            subvarvar temp alpha
+            setvarvar alpha temp
+            orvar o 32  // RS_TRANS2
+        }
+        // alpha now in [0 .. 31]
+
+        addvar alpha 101  // additive translucency tables are assumed to be at [101 .. 132]
+        mulvar alpha -1
+    }
 
     // divider line
     rotatespritea 240 65 32768 512 WINDOWBORDER1 0 2 0 85 x1 y1 x2 y2
@@ -324,4 +343,7 @@ onevent EVENT_DISPLAYREST
     screentext font 10 100 z 1536 charangle 1020 shade pal o 85 xspace yline xbetween ybetween f x1 y1 x2 y2
     orvar f TEXT_LITERALESCAPE
     screentext font 20 100 z 1536 charangle 1020 shade pal o 170 xspace yline xbetween ybetween f x1 y1 x2 y2
+
+    ifvarand o 32 xorvar o 32  // clear RS_TRANS2
+    setvar alpha 0  // Clear alpha so it's only active from PERIODIC_ALPHA to here.
 endevent