Hi,
I am drawing user-interface elements in Cocoa. I have a problem with transparent colors. I have created a minimal example to illustrate the issue. https://github.com/JeffMcClintock/AlphaBlender Here is the apps output: https://synthedit.com/files/AlphaBlender.png To explain, the app is drawing (left to right) first some solid colors (White, Black, 50% Grey), then a checkerboard pattern (50% white, 50% black), then two blends – 50% white over Black and 50% black over white. My aim is that any blend of two colors is calculated in a linear RGB color space. So ideally all 3 shades on the right would appear to be the same brightness as the checkerboard (a physical brightness half way between black and white). I think, based on the sRGB curve that the raw pixel brightness of mid-grey is 188 (on a scale of 0 – 255) i.e. hex 0xBCBCBC. This is the pixel value that I am hoping to achieve with a 50% blend of black and white. I have tried creating the NSColor with various different colorspaces, but this seems to not affect the result of the blending. Any suggestions of how I can achieve this are appreciated! Jeff _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
