![]() ![]() You do in software a similar thing as the old PAL encoder cards forĮuro-Apples did in hardware (looking at the PAL encoder schematic can Very old revision 0 motherboard) you use "hold-and-modify". The result looksįor a color monitor (but not in text modes, unless you want to emulate a You can improve the appearance by lowering theīrightness of every other line to about 60% of maximum. Shown directly probably doubling each line so that the aspect ratio is Reduced to a 560x192 monochrome represantation.įor a monochrome display (or for text modes) this 560x192 display can be Now everything that can possibly appear on the Apple screen has been For normal lowres, map to twoīlocks of 14x4 pixels each, again with the correct "color pattern". Forĭouble lores, map every byte to two blocks of 7x4 pixels each, in theĬorrect "color pattern" (see below). For text modes, map every text pixel (from the built-inĬharacter shapes) to one (80x24) or two (40x24) display pixels. Pixel in memory is mapped to two display pixels depending on the highīit, shift everything in the byte one display pixel to the right if Double hires is mapped directly (the lower 7 bits ofĮach byte), shifting everything two pixels to the right (otherwise youĭon't get the right colors in the next step). Thing (at least as far as NTSC composite Apples are concerned):Īll display modes are first mapped to an intermediate monochrome 560x192 Instead of doing a lot of half-fixes, why not implement the one true > of my gripes with the emulator - no half-pixel shifts in Hi-Res! > Coming in the next version of the emulator, I'm finally addressed one SETSOURCEPIXEL(SRCOFFS_HIRES+coloffs+x+adj+1,y+1,aColorIndex) SETSOURCEPIXEL(SRCOFFS_HIRES+coloffs+x+adj SETSOURCEPIXEL(SRCOFFS_HIRES+coloffs+x+adj+1,y SETSOURCEPIXEL(SRCOFFS_HIRES+coloffs+x+adj ,y VT_COLOR_TVEMU) || !(aPixels & aPixels))Ĭolor = ((odd ^ !(iPixel&1)) << 1) | hibit // // No white HGR If ((videotype = VT_COLOR_STANDARD) || (videotype = If (aPixels || aPixels)Ĭolor = ((odd ^ (iPixel&1)) << 1) | hibit Įlse if (aPixels & aPixels)Īctivate for fringe reduction on white hgr text -ĭrawback: loss of color mix patterns in hgr mode. Have some other debugger stuff I need to finish off. I probably won't be back in the video code for a while. I'm actually working on a doc that has all the Apple start of lineĪddresses, and documenting how the white half-pixel shifts are supposed Looks like some sort of 'mask' is created. I spent lots of time going "How the Heck can this even work?" and Today is/was the first time I've looked at the video code!! I stillĭon't understand it either. Would really like to get this implemented (quickly). (Which don't seem toĬorrespond to any multiple of the resolutions being rendered)ģ) Why color is the outermost loop in some casesĪny help you (or anyone else) could give would be much appreciated as I I understand what SETSOURCEPIXEL and MAKEWORD are doing,īut, I havn't dug deep enough to work out:ġ) Why SIZE is 10 in several of the renderersĢ) Why the column/byteval/x/y loops are 16,256, or 512. Maybe you could give me a brief description of how a render function is How applewin does it, but, I don't think it's using the high-bit).Īnyway, since we are both looking at the same area of the code (video.cpp), ![]() Even after looking at the code I'm not sure Applewin seems to address the problem creating readableįringed text in DHGR, but, fails to render some graphics very well as a Oasis, and MESS don't implement this mode at all and any game using text inĭHGR is unplayable. Of games seem to use this for text on DHGR screens. (mono) with 140x192 (16col) modes on screen simultaneously per 4-bits. In brief, the high bit of each DHGR byte should determine whether anyįour-bit-group with pixel-0 located in that byte should be 4 monochrome There is a good description of how this should work on: With all apple emulators: lack of decent mode3 DHGR implementation. I've been looking at the emulator source trying to address a gripe I have ![]()
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