From d88313b69ae7cc6ed87c3e016c0234e09a515b53 Mon Sep 17 00:00:00 2001
From: Per Hedbor <ph@opera.com>
Date: Mon, 28 Jun 1999 02:43:06 +0200
Subject: [PATCH] Added screen and overlay modes. Fixed set_alpha_value (wrong
functionpointer in add_function, and alpha >= 1 instead of > 1 in the actual
function)
Rev: src/modules/Image/layers.c:1.22
---
src/modules/Image/layers.c | 37 +++++++++++++++++++++++++++++++------
1 file changed, 31 insertions(+), 6 deletions(-)
diff --git a/src/modules/Image/layers.c b/src/modules/Image/layers.c
index 18f7e2b0b2..d5c022659c 100644
--- a/src/modules/Image/layers.c
+++ b/src/modules/Image/layers.c
@@ -1,7 +1,7 @@
/*
**! module Image
**! note
-**! $Id: layers.c,v 1.21 1999/06/22 19:26:00 mirar Exp $
+**! $Id: layers.c,v 1.22 1999/06/28 00:43:06 per Exp $
**! class Layer
**! see also: layers
**!
@@ -152,7 +152,7 @@
#include <math.h> /* floor */
-RCSID("$Id: layers.c,v 1.21 1999/06/22 19:26:00 mirar Exp $");
+RCSID("$Id: layers.c,v 1.22 1999/06/28 00:43:06 per Exp $");
#include "image_machine.h"
@@ -277,6 +277,9 @@ LMFUNC(lm_dissolve);
LMFUNC(lm_behind);
LMFUNC(lm_erase);
+LMFUNC(lm_screen);
+LMFUNC(lm_overlay);
+
struct layer_mode_desc
{
char *name;
@@ -331,8 +334,8 @@ struct layer_mode_desc
{"behind", lm_behind, 1, NULL },
{"erase", lm_erase, 1, NULL },
-/* {"screen", lm_screen, 1, NULL }, */
-/* {"overlay", lm_overlay, 1, NULL }, */
+ {"screen", lm_screen, 1, NULL },
+ {"overlay", lm_overlay, 1, NULL },
} ;
#define LAYER_MODES ((int)NELEM(layer_mode))
@@ -727,7 +730,7 @@ static void image_layer_set_alpha_value(INT32 args)
{
float f;
get_all_args("Image.Layer->set_alpha_value",args,"%F",&f);
- if (f<0.0 || f>=1.0)
+ if (f<0.0 || f>1.0)
SIMPLE_BAD_ARG_ERROR("Image.Layer->set_alpha_value",1,"float(0..1)");
THIS->alpha_value=f;
}
@@ -1606,6 +1609,27 @@ static void lm_normal(rgb_group *s,rgb_group *l,rgb_group *d,
#undef L_CHANNEL_DO_V
#undef LM_FUNC
+/* screen: 255 - ((255-A)*(255-B)/255) */
+
+#define LM_FUNC lm_screen
+#define L_TRUNC(X) (X<0?0:(X>255?255:X))
+#define L_OPER(A,B) 255 - CCUT((255-A)*(int)(255-B))
+#include "layer_oper.h"
+#undef LM_FUNC
+#undef L_TRUNC
+#undef L_OPER
+
+#define LM_FUNC lm_overlay
+#define L_TRUNC(X) (X)
+#define INT_MULT(a,b) (((a) * (b) + 0x80)>>8)
+#define INT_BLEND(a,b,alpha) (INT_MULT((a)-(b), alpha) + (b))
+#define L_OPER(A,B) INT_BLEND((255-INT_MULT((255-A),(255-B))),INT_MULT(A,B),A)
+/* screen mult source */
+#include "layer_oper.h"
+#undef LM_FUNC
+#undef L_TRUNC
+#undef L_OPER
+
/* darken: min v */
#define LM_FUNC lm_darken
@@ -2475,7 +2499,8 @@ void init_image_layers(void)
ADD_FUNCTION("set_fill",image_layer_set_fill,
tFunc(tOr(tObj,tVoid) tOr(tObj,tVoid),tObj),0);
ADD_FUNCTION("set_mode",image_layer_set_mode,tFunc(tStr,tObj),0);
- ADD_FUNCTION("set_alpha_value",image_layer_set_mode,tFunc(tFloat,tObj),0);
+ ADD_FUNCTION("set_alpha_value",image_layer_set_alpha_value,
+ tFunc(tFloat,tObj),0);
ADD_FUNCTION("set_tiled",image_layer_set_tiled,tFunc(tInt,tObj),0);
/* query */
--
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