[DEV BUG] Inverted Y coordinate passed to per-pixel expressions

[kblaschke]

Please confirm the following points:

• This report is NOT about the Android apps in the Play Store
• I have searched the project page to check if the issue was already reported

Affected Project

libprojectM (including the playlist library)

Affected Version

No response

Operating Systems and Architectures

All

Build Tools

No response

Additional Project, OS and Toolset Details

No response

Type of Defect

Graphical issue (rendering glitches, no or broken rendering result)

Log Output

Describe the Issue

Values passed in y variable into the per-pixel expressions are flipped, causing issues with presets requiring different directional warping in the Y axis depending on the actual position (e.g. moving in- or outwards from the warp center).

The issue is in this line here:

projectm/src/libprojectM/MilkdropPreset/PerPixelMesh.cpp

Line 233 in de1f1b6

*perPixelContext.y = static_cast<double>(curVertex.Y() * -0.5f * presetState.renderContext.aspectY + 0.5f);

Removing the - in the curVertex.Y() * -0.5f subexpressions fixes the issue.

[OfficialIncubo]

There is also a problem with ang variable, but I don't know where I can find the problematic part out there.

Here's an image of my self-made preset test comparing the ang variable on BeatDrop and projectM.