?? sdlgraphics.cpp
字號:
SDL_UnlockSurface(mTarget); } void SDLGraphics::drawVLine(int x, int y1, int y2) { ClipRectangle top = mClipStack.top(); x += top.xOffset; y1 += top.yOffset; y2 += top.yOffset; if (x < top.x || x >= top.x + top.width) return; if (y1 > y2) { y1 ^= y2; y2 ^= y1; y1 ^= y2; } if (top.y > y1) { if (top.y > y2) { return; } y1 = top.y; } if (top.y + top.height <= y2) { if (top.y + top.height <= y1) { return; } y2 = top.y + top.height - 1; } int bpp = mTarget->format->BytesPerPixel; SDL_LockSurface(mTarget); Uint8 *p = (Uint8 *)mTarget->pixels + y1 * mTarget->pitch + x * bpp; Uint32 pixel = SDL_MapRGB(mTarget->format, mColor.r, mColor.g, mColor.b); switch(bpp) { case 1: { for (;y1 <= y2; ++y1) { *p = pixel; p += mTarget->pitch; } } break; case 2: { for (;y1 <= y2; ++y1) { *(Uint16*)p = pixel; p += mTarget->pitch; } } break; case 3: { if(SDL_BYTEORDER == SDL_BIG_ENDIAN) { for (;y1 <= y2; ++y1) { p[0] = (pixel >> 16) & 0xff; p[1] = (pixel >> 8) & 0xff; p[2] = pixel & 0xff; p += mTarget->pitch; } } else { for (;y1 <= y2; ++y1) { p[0] = pixel & 0xff; p[1] = (pixel >> 8) & 0xff; p[2] = (pixel >> 16) & 0xff; p += mTarget->pitch; } } } break; case 4: { for (;y1 <= y2; ++y1) { if (mAlpha) { *(Uint32*)p = SDLAlpha32(pixel,*(Uint32*)p,mColor.a); } else { *(Uint32*)p = pixel; } p += mTarget->pitch; } } break; } // end switch SDL_UnlockSurface(mTarget); } void SDLGraphics::drawRectangle(const Rectangle& rectangle) { int x1 = rectangle.x; int x2 = rectangle.x + rectangle.width - 1; int y1 = rectangle.y; int y2 = rectangle.y + rectangle.height - 1; drawHLine(x1, y1, x2); drawHLine(x1, y2, x2); drawVLine(x1, y1, y2); drawVLine(x2, y1, y2); } void SDLGraphics::drawLine(int x1, int y1, int x2, int y2) { if (x1 == x2) { drawVLine(x1, y1, y2); return; } if (y1 == y2) { drawHLine(x1, y1, x2); return; } ClipRectangle top = mClipStack.top(); x1 += top.xOffset; y1 += top.yOffset; x2 += top.xOffset; y2 += top.yOffset; // Draw a line with Bresenham int dx = ABS(x2 - x1); int dy = ABS(y2 - y1); if (dx > dy) { if (x1 > x2) { // swap x1, x2 x1 ^= x2; x2 ^= x1; x1 ^= x2; // swap y1, y2 y1 ^= y2; y2 ^= y1; y1 ^= y2; } if (y1 < y2) { int y = y1; int p = 0; for (int x = x1; x <= x2; x++) { if (top.isPointInRect(x, y)) { if (mAlpha) { SDLputPixelAlpha(mTarget, x, y, mColor); } else { SDLputPixel(mTarget, x, y, mColor); } } p += dy; if (p * 2 >= dx) { y++; p -= dx; } } } else { int y = y1; int p = 0; for (int x = x1; x <= x2; x++) { if (top.isPointInRect(x, y)) { if (mAlpha) { SDLputPixelAlpha(mTarget, x, y, mColor); } else { SDLputPixel(mTarget, x, y, mColor); } } p += dy; if (p * 2 >= dx) { y--; p -= dx; } } } } else { if (y1 > y2) { // swap y1, y2 y1 ^= y2; y2 ^= y1; y1 ^= y2; // swap x1, x2 x1 ^= x2; x2 ^= x1; x1 ^= x2; } if (x1 < x2) { int x = x1; int p = 0; for (int y = y1; y <= y2; y++) { if (top.isPointInRect(x, y)) { if (mAlpha) { SDLputPixelAlpha(mTarget, x, y, mColor); } else { SDLputPixel(mTarget, x, y, mColor); } } p += dx; if (p * 2 >= dy) { x++; p -= dy; } } } else { int x = x1; int p = 0; for (int y = y1; y <= y2; y++) { if (top.isPointInRect(x, y)) { if (mAlpha) { SDLputPixelAlpha(mTarget, x, y, mColor); } else { SDLputPixel(mTarget, x, y, mColor); } } p += dx; if (p * 2 >= dy) { x--; p -= dy; } } } } } void SDLGraphics::setColor(const Color& color) { mColor = color; mAlpha = color.a != 255; } const Color& SDLGraphics::getColor() { return mColor; } void SDLGraphics::drawSDLSurface(SDL_Surface* surface, SDL_Rect source, SDL_Rect destination) { ClipRectangle top = mClipStack.top(); destination.x += top.xOffset; destination.y += top.yOffset; SDL_BlitSurface(surface, &source, mTarget, &destination); }}?? 快捷鍵說明
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