Replace desktop backend with SDL3 GL and ANGLE-GLES by riccardobl · Pull Request #2585 · jMonkeyEngine/jmonkeyengine

riccardobl · 2026-01-25T14:38:40Z

This started with the intention of adapting the current glfw+lwjgl3 backend to use angle, but it turned out that glfw has some major limitations that break angle in wayland.

After trying to workaround these limitations, with no success, I decided to rewrite (with the help of gpt 5.3) the entire lwjgl3 backend to use SDL3, that is now available in lwjgl 3.4 and that we are already using for controllers (due to, again, more glfw limitations).

That said, this is a summary of what this PR does:

entirely replaces glfw with sdl3
- removes glfw dependency
implements angle built here
replaces the unreliable sRGB default framebuffer with an offscreen framebuffer
- when gamma correction = true an offscreen RGBA16F framebuffer is passed to jme
- jme renders to it as usual (doesn't even know it is not the default fb)
- the offscreen fb is converted to srgb and blitted to the default framebuffer automatically using a shader
removes opencl
- as discussed, it is mostly untested and unused and doesn't work on every platform we support
deprecates every opengl version before 3.2
set some better defaults (related to Plan to remove default dependency from AWT Settings launcher #2626)

This is still a work in progress, but it is a step forward in making GLES 3.0 the jME baseline across every platform.

github-actions · 2026-01-25T14:40:58Z

🖼️ Screenshot tests have failed.

The purpose of these tests is to ensure that changes introduced in this PR don't break visual features. They are visual unit tests.

📄 Where to find the report:

Direct Download: screenshot-test-report
Alternatively, go to the failed run summary > Artifacts > screenshot-test-report
Download the zip and open jme3-screenshot-tests/build/reports/ScreenshotDiffReport.html

⚠️ If you didn't expect to change anything visual:
Fix your changes so the screenshot tests pass.

✅ If you did mean to change things:
Review the replacement images in jme3-screenshot-tests/build/changed-images to make sure they really are improvements and then replace and commit the replacement images at jme3-screenshot-tests/src/test/resources.

✨ If you are creating entirely new tests:
Find the new images in jme3-screenshot-tests/build/changed-images and commit the new images at jme3-screenshot-tests/src/test/resources.

Note; it is very important that the committed reference images are created on the build pipeline, locally created images are not reliable. Similarly tests will fail locally but you can look at the report to check they are "visually similar".

See https://github.com/jMonkeyEngine/jmonkeyengine/blob/master/jme3-screenshot-tests/README.md for more information

Contact @richardTingle (aka richtea) for guidance if required

Copilot

Pull request overview

This PR is a work-in-progress refactor of the LWJGL3 backend to replace GLFW with SDL3, introduce an ANGLE/GLES3 rendering path, and simplify/remodel related rendering + native loading behavior (including removal of LWJGL OpenCL support).

Changes:

Replaces GLFW-based input/windowing with SDL3 implementations (mouse/keyboard/joysticks) and updates LWJGL context initialization to support ANGLE/GLES3.
Adds auxiliary framebuffer shader/material resources and updates multisample/sRGB handling logic.
Removes LWJGL OpenCL integration code and updates defaults (renderer + window defaults) and native-library loading behavior.

Reviewed changes

Copilot reviewed 49 out of 50 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
jme3-lwjgl3/src/main/resources/Common/MatDefs/Post/AuxFramebuffer.vert	Adds vertex shader for auxiliary framebuffer pass-through.
jme3-lwjgl3/src/main/resources/Common/MatDefs/Post/AuxFramebuffer.j3md	Adds material definition for auxiliary framebuffer blit/resolve.
jme3-lwjgl3/src/main/resources/Common/MatDefs/Post/AuxFramebuffer.frag	Adds fragment shader to resolve MSAA (via MultiSample) and linear→sRGB encode.
jme3-lwjgl3/src/main/java/com/jme3/system/lwjgl/WindowSizeListener.java	Removes GLFW-specific javadoc wording.
jme3-lwjgl3/src/main/java/com/jme3/system/lwjgl/LwjglDisplay.java	Removes unused import.
jme3-lwjgl3/src/main/java/com/jme3/system/lwjgl/LwjglContext.java	Adds ANGLE/GLES init path, removes OpenCL, updates sRGB detection/flags.
jme3-lwjgl3/src/main/java/com/jme3/system/lwjgl/LwjglCanvas.java	Drops GL < 3.2 configs; forces core profile defaults and forward-compat.
jme3-lwjgl3/src/main/java/com/jme3/renderer/lwjgl/LwjglGLES.java	Introduces GLES wrapper for LWJGL+ANGLE backend.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/info/InfoQueryObject.java	Removes LWJGL OpenCL info querying helper.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/info/InfoQueryInt.java	Removes LWJGL OpenCL info querying helper.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/info/InfoQuery.java	Removes LWJGL OpenCL info querying helper.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/info/Info.java	Removes generated LWJGL OpenCL info query facade.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/info/CLUtil.java	Removes LWJGL OpenCL error token utilities.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/Utils.java	Removes LWJGL OpenCL buffer/util helpers.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/LwjglProgram.java	Removes LWJGL OpenCL program wrapper.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/LwjglPlatform.java	Removes LWJGL OpenCL platform wrapper.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/LwjglKernel.java	Removes LWJGL OpenCL kernel wrapper.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/LwjglImage.java	Removes LWJGL OpenCL image wrapper.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/LwjglEvent.java	Removes LWJGL OpenCL event wrapper.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/LwjglDevice.java	Removes LWJGL OpenCL device wrapper.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/LwjglContext.java	Removes LWJGL OpenCL context wrapper.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/LwjglCommandQueue.java	Removes LWJGL OpenCL command queue wrapper.
jme3-lwjgl3/src/main/java/com/jme3/opencl/lwjgl/LwjglBuffer.java	Removes LWJGL OpenCL buffer wrapper.
jme3-lwjgl3/src/main/java/com/jme3/input/lwjgl/SdlMouseInput.java	Adds SDL mouse input implementation.
jme3-lwjgl3/src/main/java/com/jme3/input/lwjgl/SdlKeyMap.java	Adds SDL scancode↔jME keycode mapping.
jme3-lwjgl3/src/main/java/com/jme3/input/lwjgl/SdlKeyInput.java	Replaces GLFW key input with SDL key/text input handling.
jme3-lwjgl3/src/main/java/com/jme3/input/lwjgl/SdlJoystickInput.java	Routes device add/remove via external SDL event dispatch method.
jme3-lwjgl3/src/main/java/com/jme3/input/lwjgl/GlfwMouseInput.java	Removes GLFW mouse input implementation.
jme3-lwjgl3/src/main/java/com/jme3/input/lwjgl/GlfwKeyMap.java	Removes GLFW key mapping.
jme3-lwjgl3/src/main/java/com/jme3/input/lwjgl/GlfwJoystickInput.java	Removes GLFW joystick input implementation.
jme3-lwjgl3/src/main/java/com/jme3/system/lwjgl/LwjglWindow.java	SDL window/context creation + ANGLE configuration hooks (and ANGLE native loading).
jme3-lwjgl3/build.gradle	Drops GLFW/OpenCL deps; adds SDL/EGL/OpenGLES + ANGLE natives.
jme3-ios/src/main/java/com/jme3/renderer/ios/JmeIosGLES.java	Adds `glGetStringi` native declaration.
jme3-ios/src/main/java/com/jme3/renderer/ios/IosGL.java	Wires `glGetString(name,index)` to iOS native `glGetStringi`.
jme3-examples/src/main/java/jme3test/material/TestUnshadedModel.java	Forces ANGLE/GLES3 settings for a sample test.
jme3-examples/src/main/java/jme3test/light/pbr/TestPBRSimple.java	Adjusts example startup to use explicit AppSettings.
jme3-effects/src/main/resources/Common/MatDefs/Post/ToneMap.frag	Switches multisample support to MultiSample.glsllib import.
jme3-effects/src/main/resources/Common/MatDefs/Post/KHRToneMap.frag	Switches multisample support to MultiSample.glsllib import.
jme3-desktop/src/main/java/jme3tools/converters/ImageToAwt.java	Converts some formats to GLES-friendly equivalents before encode.
jme3-desktop/src/main/java/com/jme3/texture/plugins/AWTLoader.java	Converts BGR/ABGR sources to RGB/RGBA output formats.
jme3-desktop/src/main/java/com/jme3/system/NativeLibraryLoader.java	Adds `LibraryInfo` registration overload; returns absolute path from `loadNativeLibrary`.
jme3-desktop/src/main/java/com/jme3/system/JmeDesktopSystem.java	Accepts ANGLE renderer prefix for LWJGL context creation.
jme3-core/src/plugins/java/com/jme3/texture/plugins/TGALoader.java	Converts 24-bit BGR TGA data to RGB and updates format.
jme3-core/src/main/resources/Common/ShaderLib/MultiSample.glsllib	Adds EXT multisampled render-to-texture extension support and broadens GLES condition.
jme3-core/src/main/java/com/jme3/system/AppSettings.java	Deprecates old LWJGL renderer strings; adds ANGLE_GLES3 and updates defaults.
jme3-core/src/main/java/com/jme3/renderer/opengl/GLRenderer.java	Adds GLES extension enumeration via `glGetStringi`; updates multisample capability detection.
jme3-core/src/main/java/com/jme3/renderer/opengl/GLES_30.java	Adds `GL_NUM_EXTENSIONS` and `glGetString(name,index)` API.
gradle/libs.versions.toml	Adds LWJGL OpenGLES + EGL modules to the version catalog.
common.gradle	Adds maven repo for ANGLE native artifacts.
.gitignore	Formatting-only change to an ignore entry.

Comments suppressed due to low confidence (1)

jme3-lwjgl3/src/main/java/com/jme3/input/lwjgl/SdlKeyInput.java:144

update() returns early when listener == null, but queued events are never drained/cleared. If SDL events are still being forwarded via onSDLEvent(...), this can cause unbounded queue growth and stale key events once a listener is attached later. Consider clearing keyInputEvents when listener == null (similar to SdlMouseInput.update()) or avoiding enqueuing events when there's no listener.

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8Keep · 2026-04-15T15:45:08Z

@riccardobl Could you split this out into multiple PRs? Opencl removal, gles 2 removal, could be very independent and land before the main changes here are ready.

riccardobl · 2026-04-15T15:52:42Z

@riccardobl Could you split this out into multiple PRs? Opencl removal, gles 2 removal, could be very independent and land before the main changes here are ready.

The goal of this PR is to implement ANGLE in jme, everything else is just a side effect of that.

GLFW is replaced with SDL because it does not support angle very well on wayland
OpenCL is dropped because angle does not support it
GL2 is dropped because it becomes useless with ANGLE and it would be just be extra effort to implement in SDL

So, this is actually a single feature, there is no point in implementing any of these changes on their own in the current jme , and splitting this would make it much harder to test.

The blocker here is just that I need to test it on a real project and implement ios support

This reverts commit 79734e7.

This reverts commit f0a76dc740a9cd370cf76891d5edc8f8f2e103b6.

… bug that causes lwjgl apps to break

Copilot

Pull request overview

Copilot reviewed 58 out of 59 changed files in this pull request and generated 6 comments.

Comments suppressed due to low confidence (1)

jme3-lwjgl3/src/main/java/com/jme3/input/lwjgl/SdlKeyInput.java:145

When listener is null, update() returns without draining keyInputEvents. If SDL events keep arriving (e.g., when UseInput is false or the listener is set later), this queue can grow unbounded. Consider clearing the queue when listener == null (similar to SdlMouseInput).

riccardobl · 2026-05-09T12:46:59Z

 #extension GL_ARB_texture_multisample : enable
+#extension GL_EXT_multisampled_render_to_texture : enable


riccardobl · 2026-05-09T12:46:40Z

+                if (settings.getBoolean("GraphicsTrace")) {
+                    gles = (LwjglGLES) GLTracer.createGlesTracer(gles, GL.class, GLES_30.class, GLFbo.class,
+                            GLExt.class);


@copilot apply changes based on this feedback

+    maven { 
+       url = uri("https://central.sonatype.com/repository/maven-snapshots")


Copilot

Pull request overview

Copilot reviewed 58 out of 59 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

jme3-lwjgl3/src/main/java/com/jme3/input/lwjgl/SdlKeyInput.java:145

update() returns early when listener == null but does not drain/clear keyInputEvents. If the listener is temporarily unset (or input is disabled), the queue can grow without bound and then replay stale events later. Consider mirroring SdlMouseInput.update() by clearing the queue when there is no listener (and/or when the context isn’t renderable).

Fix issues in GLES backends

0d3be6c

riccardobl added Contribution welcome To be investigated Feature Request / Proposal Request a feature or propose an idea labels Jan 25, 2026

riccardobl force-pushed the angle branch from 700612c to 42680ac Compare January 25, 2026 14:39

riccardobl marked this pull request as draft January 25, 2026 14:39

riccardobl changed the title ~~Angle backend (Work in progress)~~ Angle GLES backend for desktop (Work in progress) Jan 25, 2026

riccardobl mentioned this pull request Jan 26, 2026

Feature Request: Add Google ANGLE backend #1425

Closed

rewrite lwjgl3 backend to use SDL

9a63ca1

riccardobl force-pushed the angle branch from 42680ac to 9a63ca1 Compare March 20, 2026 22:28

riccardobl added 5 commits March 21, 2026 00:30

remove debug libraries

5b00164

support msaa framebuffer extension in gles

fe52fef

use auxiliary framebuffer for srgb conversion

fd4512a

deprecate old opengl versions

812eecc

update deps

76da689

riccardobl changed the title ~~Angle GLES backend for desktop (Work in progress)~~ New GL/GLES backend for jme (Work in progress) Mar 21, 2026

riccardobl requested a review from Copilot March 28, 2026 10:20

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riccardobl added 8 commits May 5, 2026 20:14

Merge remote-tracking branch 'upstream/master' into angle

05a9d64

use lib catalog for angle native

0f94445

Merge remote-tracking branch 'upstream/master' into angle

2b7c025

Merge branch 'glespatch' into angle

5706c46

fix

a257bed

remove debug override

182e94f

update libs

b15c60f

add task to run tests in proton

2927234

riccardobl added enhancement and removed Contribution welcome To be investigated Feature Request / Proposal Request a feature or propose an idea labels May 9, 2026

riccardobl and others added 5 commits May 9, 2026 08:50

Merge branch 'master' into angle

c3c1fc8

use Blit.j3md for gamma correction

31af325

Revert "fixes"

ccd450f

This reverts commit 79734e7.

Reapply "fixes"

2e1d32b

This reverts commit f0a76dc740a9cd370cf76891d5edc8f8f2e103b6.

add explicit GLSL310 support for Blit material

9520f5d

riccardobl changed the title ~~New GL/GLES backend for jme (Work in progress)~~ New GL/GLES backend for jme May 9, 2026

riccardobl changed the title ~~New GL/GLES backend for jme~~ New SDL GL and ANGLE GLES backend May 9, 2026

riccardobl changed the title ~~New SDL GL and ANGLE GLES backend~~ SDL3 GL and ANGLE GLES backend May 9, 2026

riccardobl changed the title ~~SDL3 GL and ANGLE GLES backend~~ SDL3 GL and ANGLE-GLES backend May 9, 2026

riccardobl changed the title ~~SDL3 GL and ANGLE-GLES backend~~ Replace desktop backend with SDL3 GL and ANGLE-GLES May 9, 2026

riccardobl added 5 commits May 9, 2026 11:28

force GL 3.2 in screenshot tests

11c578f

add renderer selector to settings dialog

1059c81

catch swapwindow failures

34e595c

reset hint on renderer change, fix sRGB for non angle renderer

5784b2b

set __GL_THREADED_OPTIMIZATIONS=0 on start to workaround known nvidia…

a926479

… bug that causes lwjgl apps to break

riccardobl force-pushed the angle branch from 95f307a to a926479 Compare May 9, 2026 12:24

riccardobl requested a review from Copilot May 9, 2026 12:27

Copilot started reviewing on behalf of riccardobl May 9, 2026 12:28 View session

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View reviewed changes

bypass aux framebuffer if native gl

da56f14

riccardobl requested a review from Copilot May 9, 2026 12:43

Copilot started reviewing on behalf of riccardobl May 9, 2026 12:44 View session

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View reviewed changes

Comment thread jme3-lwjgl3/src/main/java/com/jme3/system/lwjgl/LwjglContext.java

Comment thread jme3-lwjgl3/src/main/java/com/jme3/system/lwjgl/LwjglWindow.java

riccardobl and others added 3 commits May 9, 2026 16:30

use isGraphicsDebug

5296808

Merge branch 'master' into angle

4c3ee3c

use 24 bit buffer in Xvfb

db3d814

		#extension GL_ARB_texture_multisample : enable
		#extension GL_EXT_multisampled_render_to_texture : enable

		maven {
		url = uri("https://central.sonatype.com/repository/maven-snapshots")

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