+ alpha tool

Lib/Makefile

@@ -14,6 +14,9 @@ all:	foo testtga
 
 7seg.o:		7seg.c		$(DEPS)
 
+alpha.o:	alpha.c		$(DEPS)
+alpha2.o:	alpha2.c	$(DEPS)
+
 basic_io.o:	basic_io.c	$(DEPS)
 bitblt.o:	bitblt.c	$(DEPS)
 bmp.o:		bmp.c		$(DEPS)		bmp.h
@@ -128,6 +131,7 @@ zoom.o:		zoom.c		$(DEPS)
 #-----------------------------------------------------------------
 
 OBJECTS =	7seg.o							\
+		alpha.o alpha2.o					\
 		basic_io.o bitblt.o bmp.o				\
 		cadres2.o cadres3.o cadres4.o cadres84.o cadresbox.o	\
 		cadres.o						\

Lib/alpha2.c

@@ -0,0 +1,129 @@
+/*
+		alpha2.c
+		--------
+	Various transparency operations, aka "alpha channel ops"
+
+*/
+
+#include  <stdio.h>
+#include  <stdlib.h>
+#include  <string.h>
+#include  "tthimage.h"
+
+/*::------------------------------------------------------------------::*/
+int	Image_alpha_setvalue(Image_Desc *dst, int v_alpha)
+{
+int	y;
+
+#if DEBUG_LEVEL
+fprintf(stderr, "%s : %d -> %p\n", __func__, v_alpha, dst);
+#endif
+
+if (dst->type != IMAGE_RGBA)
+	{
+	fprintf(stderr, "%s : picz %p haz no alpha\n", __func__, dst);
+#if MUST_ABORT
+	abort();
+#endif
+	return NO_ALPHA_CHANNEL;
+	}
+
+for (y=0; y<dst->height; y++)
+	{
+	memset(dst->Apix[y], v_alpha, dst->width);
+	}
+dst->modified   = 1;
+return OLL_KORRECT;
+}
+/*::------------------------------------------------------------------::*/
+/*
+ *	values of r,g,b pixels are scaled by alpha value.
+ */
+int
+Image_alpha_reduce(Image_Desc *src, Image_Desc *dst, int yo)
+{
+int	foo, x, y;
+int	r, g, b, a;
+
+#if DEBUG_LEVEL
+fprintf(stderr, "Image: alpha reduce: %p -> %p (yo=%d)\n", src, dst, yo);
+#endif
+
+if (src->type != IMAGE_RGBA)
+    {
+    fprintf(stderr, "Image: alpha reduce: %p is not RGBA", src);
+    return NO_ALPHA_CHANNEL;
+    }
+
+if ( (foo=Image_compare_desc(src, dst)) )
+    {
+    fprintf(stderr, "Image: alpha reduce: images are differents %d\n", foo);
+    return foo;
+    }
+
+for (y=0; y<src->height; y++)
+	{
+	for (x=0; x<src->width; x++)
+		{
+		Image_getRGBA(src, x, y, &r, &g, &b, &a);
+		r = (r * a) / 256;
+		g = (g * a) / 256;
+		b = (b * a) / 256;
+		Image_plotRGB(dst, x, y, r, g, b);
+		}
+	}
+
+dst->modified   = 1;
+
+return FUNC_IS_BETA;
+}
+/*::------------------------------------------------------------------::*/
+/*
+ *	this fonction need more explanations :(
+ */
+int
+Image_poke_alpha_from_rgb(Image_Desc *src, Image_Desc *dst, 
+					int fr, int fg, int fb, int flag)
+{
+int	foo, x, y, r, g, b, a0, a1, a;
+
+a = 0;		/* warning shutdown */
+
+if ( (foo=Image_compare_desc(src, dst)) )
+    {
+    fprintf(stderr, "Poke alpha from rgb: images are differents %d\n", foo);
+    return foo;
+    }
+
+if ( dst->Apix == NULL )
+    {
+    fprintf(stderr, "poke alpha from rgb: dest image have NO alpha channel\n");
+    return NO_ALPHA_CHANNEL;
+    }
+
+a0 = flag ? 0 : 255;
+a1 = flag ? 255 : 0;
+
+#if DEBUG_LEVEL
+fprintf(stderr, "For rgb = %d,%d,%d  alpha wil be %d\n", fr, fg, fb, a);
+#endif
+
+for (y=0; y<src->height; y++)
+	{
+	for (x=0; x<src->width; x++)
+		{
+		Image_getRGB(src, x, y, &r, &g, &b);
+
+		if (r==fr && g==fg && b==fb)	a = a0;
+		else				a = a1;
+
+		Image_plotRGBA(dst, x, y, r, g, b, a);
+		}
+	}
+
+dst->modified   = 1;
+
+return FUNC_NOT_FINISH;
+}
+/*::------------------------------------------------------------------::*/
+