From 0358d9b382057ad45ba86882b55bc4cec630e726 Mon Sep 17 00:00:00 2001
From: Jens Arnold <amiconn@rockbox.org>
Date: Tue, 10 Feb 2009 01:23:18 +0000
Subject: Simulate backlight for colour targets. Implements the idea from FS
 #9884, but uses SDL alpha blending. Display is dimmed to 1/3 for targets with
 transflective LCD, and set to black for others.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19961 a1c6a512-1295-4272-9138-f99709370657
---
 uisimulator/sdl/lcd-bitmap.c | 24 +++++++++++++++++++-----
 uisimulator/sdl/lcd-sdl.c    |  3 +++
 2 files changed, 22 insertions(+), 5 deletions(-)

(limited to 'uisimulator/sdl')

diff --git a/uisimulator/sdl/lcd-bitmap.c b/uisimulator/sdl/lcd-bitmap.c
index b4e6dcd4c0..8caac784ef 100644
--- a/uisimulator/sdl/lcd-bitmap.c
+++ b/uisimulator/sdl/lcd-bitmap.c
@@ -63,7 +63,16 @@ SDL_Color lcd_color2_bright = {RED_CMP(LCD_BRIGHTCOLOR_2),
 #else
 #define NUM_SHADES    129
 #endif
-#endif /* LCD_DEPTH <= 8 */
+
+#else /* LCD_DEPTH > 8 */
+
+#ifdef HAVE_TRANSFLECTIVE_LCD
+#define BACKLIGHT_OFF_ALPHA 85 /* 1/3 brightness */
+#else
+#define BACKLIGHT_OFF_ALPHA 0  /* pitch black */
+#endif
+
+#endif /* LCD_DEPTH */
 
 #if LCD_DEPTH < 8
 unsigned long (*lcd_ex_getpixel)(int, int) = NULL;
@@ -135,12 +144,17 @@ void sim_backlight(int value)
                          &lcd_color2_bright, NUM_SHADES, NUM_SHADES);
 #endif
     }
+#else /* LCD_DEPTH > 8 */
+    if (value > 0) {
+        SDL_SetAlpha(lcd_surface, 0, SDL_ALPHA_OPAQUE); /* full on */
+    } else {
+        SDL_SetAlpha(lcd_surface, SDL_SRCALPHA, BACKLIGHT_OFF_ALPHA);
+    }
+#endif /* LCD_DEPTH */
+
     sdl_gui_update(lcd_surface, 0, 0, SIM_LCD_WIDTH, SIM_LCD_HEIGHT,
                    SIM_LCD_WIDTH, SIM_LCD_HEIGHT,
                    background ? UI_LCD_POSX : 0, background? UI_LCD_POSY : 0);
-#else /* LCD_DEPTH > 8 */
-    (void)value; /* not yet simulated */
-#endif /* LCD_DEPTH */
 }
 #endif /* HAVE_BACKLIGHT */
 
@@ -153,7 +167,7 @@ void sim_lcd_init(void)
                                        SIM_LCD_HEIGHT * display_zoom,
                                        LCD_DEPTH, 0, 0, 0, 0);
 #else
-    lcd_surface = SDL_CreateRGBSurface(SDL_SWSURFACE, 
+    lcd_surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
                                        SIM_LCD_WIDTH * display_zoom,
                                        SIM_LCD_HEIGHT * display_zoom,
                                        8, 0, 0, 0, 0);
diff --git a/uisimulator/sdl/lcd-sdl.c b/uisimulator/sdl/lcd-sdl.c
index 373e07ffc0..aa74c14cd9 100644
--- a/uisimulator/sdl/lcd-sdl.c
+++ b/uisimulator/sdl/lcd-sdl.c
@@ -90,6 +90,9 @@ void sdl_gui_update(SDL_Surface *surface, int x_start, int y_start, int width,
     SDL_Rect dest= {(ui_x + x_start) * display_zoom, (ui_y + y_start) * display_zoom,
                     xmax * display_zoom, ymax * display_zoom};
 
+    if (surface->flags & SDL_SRCALPHA) /* alpha needs a black background */
+        SDL_FillRect(gui_surface, &dest, 0);
+
     SDL_BlitSurface(surface, &src, gui_surface, &dest);
 
     SDL_Flip(gui_surface);
-- 
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