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Added an experimental screen transition dirty rect calculation code which should make background changes faster on slower devices or when scalers are active

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svn-id: r44032
This commit is contained in:
Paul Gilbert 2009-09-11 11:36:16 +00:00
parent bb94053960
commit 4fc8fe8023
3 changed files with 45 additions and 1 deletions
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42
engines/cruise/gfxModule.cpp
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@ -330,4 +330,46 @@ void resetBitmap(uint8 *dataPtr, int32 dataSize) {
memset(dataPtr, 0, dataSize);
}
/**
* This method compares a new background being switched in against the current background,
* to figure out rectangles of changed areas for dirty rectangles
*/
void switchBackground(const byte *newBg) {
const byte *bg = gfxModuleData.pPage00;
int sliceXStart, sliceXEnd;
// If both the upper corners are different, presume it's a full screen change
if ((*newBg != *bg) && (*(newBg + 319) != *(bg + 319))) {
gfxModuleData_addDirtyRect(Common::Rect(0, 0, 320, 200));
return;
}
/* For an optimisation, any changes are stored as a series of slices than have a height of a single
* line each. It is left up to the screen redraw code to automatically merge these together
*/
for (int yp = 0; yp < 200; ++yp) {
sliceXStart = -1; sliceXEnd = -1;
for (int xp = 0; xp < 320; ++xp, ++bg, ++newBg) {
if (*bg != *newBg) {
if (sliceXStart == -1) {
// Start of a new slice
sliceXStart = xp;
sliceXEnd = MIN(xp + 7, 320);
} else
// Carry on of changed area
sliceXEnd = MAX(xp + 7, sliceXEnd);
} else if ((sliceXEnd != -1) && (xp >= (sliceXEnd + 10))) {
// If more than 10 pixels have gone by without any changes, then end the slice
gfxModuleData_addDirtyRect(Common::Rect(sliceXStart, yp, sliceXEnd, yp + 1));
sliceXStart = sliceXEnd = -1;
}
}
if (sliceXStart != -1)
gfxModuleData_addDirtyRect(Common::Rect(sliceXStart, yp, 320, yp + 1));
}
}
} // End of namespace Cruise

2
engines/cruise/gfxModule.h
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@ -67,6 +67,8 @@ void flip(void);
void drawSolidBox(int32 x1, int32 y1, int32 x2, int32 y2, uint8 colour);
void resetBitmap(uint8 *dataPtr, int32 dataSize);
void switchBackground(const byte *newBg);
} // End of namespace Cruise
#endif

2
engines/cruise/mainDraw.cpp
View File

@ -1415,7 +1415,7 @@ void mainDraw(int16 param) {
gfxModuleData_gfxCopyScreen(bgPtr, gfxModuleData.pPage10);
if (backgroundChanged[masterScreen]) {
backgroundChanged[masterScreen] = false;
gfxModuleData_addDirtyRect(Common::Rect(0, 0, 320, 200));
switchBackground(bgPtr);
}
}