The HD Mode 7 mod fixes this problem by making use of modern computer hardware to perform its matrix math 'at the output resolution,' upscaling the original tiles before any transformations are done.

Translating those transformation results back to SNES-scale tiles and a 420p SD screen leads to some problems on the edges of objects, which can look lumpy and 'off' by a pixel or two at certain points on the screen. It's a clever effect but one that can make the underlying map data look especially smeary and blob-like, especially for parts of the map that are 'far away.' This smearing is exacerbated by the SNES' matrix math implementation, which uses trigonometric lookup tables and rounding to cut down on the time needed to perform all that linear algebra on '90s-era consumer hardware. These games would essentially draw every horizontal scanline in a single SDTV frame at a different scale, making pieces lower in the image appear 'closer' than ones far away.

Some Mode 7 games also made use of an additional HDMA mode (Horizontal-blanking Direct Memory Access) to fake a '3D' plane that stretches off into the horizon. That made for a 1024×1024 'map' that could be manipulated en masse by basic linear algebra affine transforms to rotate, scale, shear, and translate the entire screen quickly. Games that made use of the SNES 'Graphics Mode 7' used backgrounds that were coded in the SNES memory as a 128x128 grid of 256-color, 8x8 pixel tiles. That makes this project different from upscaling emulation efforts for the N64 and other retro consoles, which often require hand-drawn HD texture packs to make old art look good at higher resolutions. Perhaps the most impressive thing about these effects is that they take place on original SNES ROM and graphics files DerKoun has said that 'no artwork has been modified' in the games since the project was just a proof of concept a month ago. Pieces of Mode 7 maps that used to be boxy smears of color far in the distance are now sharp, straight lines with distinct borders and distinguishable features. The results, as you can see in the above gallery and the below YouTube video, are practically miraculous. at up to 4 times the horizontal and vertical resolution' of the original hardware.

In their own words, the patch 'performs Mode 7 transformations. A modder going by the handle DerKoun has released an 'HD Mode 7' patch for the accuracy-focused SNES emulator bsnes. Further Reading Accuracy takes power: one man’s 3GHz quest to build a perfect SNES emulatorEmulation to the rescue.

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