create offscreen surface so we can set its RGB ordering to match our internals

git-svn-id: http://skia.googlecode.com/svn/trunk@187 2bbb7eff-a529-9590-31e7-b0007b416f81

include/views/SkOSWindow_SDL.h

@@ -22,7 +22,8 @@
 
 class SkOSWindow : public SkWindow {
 public:
-    SkOSWindow(void* surface);
+    SkOSWindow(void* screen);
+    virtual ~SkOSWindow();
 
     static bool PostEvent(SkEvent* evt, SkEventSinkID, SkMSec delay);
 
@@ -36,6 +37,7 @@ protected:
     virtual void onSetTitle(const char[]);
 
 private:
+    SDL_Surface* fScreen;
     SDL_Surface* fSurface;
 
     void doDraw();

src/utils/SDL/SkOSWindow_SDL.cpp

@@ -1,5 +1,6 @@
 #include "SkOSWindow_SDL.h"
 #include "SkCanvas.h"
+#include "SkColorPriv.h"
 #include "SkOSMenu.h"
 #include "SkTime.h"
 
@@ -32,9 +33,21 @@ static bool skia_setBitmapFromSurface(SkBitmap* dst, SDL_Surface* src) {
     return true;
 }
 
-SkOSWindow::SkOSWindow(void* surface) {
-    fSurface = reinterpret_cast<SDL_Surface*>(surface);
-    this->resize(fSurface->w, fSurface->h);
+SkOSWindow::SkOSWindow(void* screen) {
+    fScreen = reinterpret_cast<SDL_Surface*>(screen);
+    this->resize(fScreen->w, fScreen->h);
+    
+    uint32_t rmask = SK_R32_MASK << SK_R32_SHIFT;
+    uint32_t gmask = SK_G32_MASK << SK_G32_SHIFT;
+    uint32_t bmask = SK_B32_MASK << SK_B32_SHIFT;
+    uint32_t amask = SK_A32_MASK << SK_A32_SHIFT;
+
+    fSurface = SDL_CreateRGBSurface(SDL_SWSURFACE, fScreen->w, fScreen->h, 32,
+                                    rmask, gmask, bmask, amask);
+}
+
+SkOSWindow::~SkOSWindow() {
+    SDL_FreeSurface(fSurface);
 }
 
 void SkOSWindow::doDraw() {
@@ -54,7 +67,12 @@ void SkOSWindow::doDraw() {
     if ( SDL_MUSTLOCK(fSurface) ) {
         SDL_UnlockSurface(fSurface);
     }
-    SDL_UpdateRect(fSurface, 0, 0, fSurface->w, fSurface->h);
+
+    int result = SDL_BlitSurface(fSurface, NULL, fScreen, NULL);
+    if (result) {
+        SkDebugf("------- SDL_BlitSurface returned %d\n", result);
+    }
+    SDL_UpdateRect(fScreen, 0, 0, fScreen->w, fScreen->h);
 }
 
 static SkKey find_skkey(SDLKey src) {

xcode/sampleapp_sdl/skia_sdl_main.cpp

@@ -15,10 +15,13 @@
 #include "SkApplication.h"
 #include "SkWindow.h"
 
+#define WINDOW_WIDTH    800
+#define WINDOW_HEIGHT   600
+
 int main(int argc, char *argv[]) {
 	Uint32 initflags = SDL_INIT_VIDEO | SDL_INIT_TIMER;
 	SDL_Surface *screen;
-	Uint8  video_bpp = 0;
+	Uint8  video_bpp = 32;
 	Uint32 videoflags = SDL_SWSURFACE;
     SDL_Event event;
 
@@ -30,14 +33,13 @@ int main(int argc, char *argv[]) {
 	}
 
 	/* Set 640x480 video mode */
-	screen=SDL_SetVideoMode(640,480, video_bpp, videoflags);
-        if (screen == NULL) {
-		fprintf(stderr, "Couldn't set 640x480x%d video mode: %s\n",
-                        video_bpp, SDL_GetError());
+	screen=SDL_SetVideoMode(WINDOW_WIDTH, WINDOW_HEIGHT, video_bpp, videoflags);
+    if (screen == NULL) {
+		fprintf(stderr, "Couldn't set video mode: %s\n", SDL_GetError());
 		SDL_Quit();
 		exit(2);
 	}
-    
+
     application_init();
     SkOSWindow* skwin = create_sk_window(screen);