From addd65a1602d59cef2e3cc2d64de179c03057405 Mon Sep 17 00:00:00 2001
From: Ada <ada+github@thingvellir.net>
Date: Wed, 26 Feb 2025 04:55:14 +1000
Subject: [PATCH] Canvas frame update experiment

---
 .../src/RenderableCanvasEntityItem.cpp        | 25 ++++++++++++++++++-
 .../src/RenderableCanvasEntityItem.h          |  4 +++
 .../src/RenderableEntityItem.cpp              |  5 ++++
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/libraries/entities-renderer/src/RenderableCanvasEntityItem.cpp b/libraries/entities-renderer/src/RenderableCanvasEntityItem.cpp
index 238eca3370..f1c77c26b5 100644
--- a/libraries/entities-renderer/src/RenderableCanvasEntityItem.cpp
+++ b/libraries/entities-renderer/src/RenderableCanvasEntityItem.cpp
@@ -14,7 +14,7 @@ using namespace render::entities;
 CanvasEntityRenderer::CanvasEntityRenderer(const EntityItemPointer& entity) : Parent(entity) {
     gpu::Byte pixels[256 * 256 * 4];
 
-    // grayscale XOR placeholder texture
+    // dummy placeholder texture to make sure the per-frame thing works
     for (int x = 0; x < 256; x++) {
         for (int y = 0; y < 256; y++) {
             pixels[(y * 256 * 4) + (x * 4) + 0] = 255;
@@ -28,6 +28,29 @@ CanvasEntityRenderer::CanvasEntityRenderer(const EntityItemPointer& entity) : Pa
     _texture->setStoredMipFormat(gpu::Element::COLOR_SRGBA_32);
     _texture->assignStoredMip(0, 256 * 256 * 4, pixels);
     _texture->setSource(__FUNCTION__);
+
+    _testTimer.setInterval(33);
+    connect(&_testTimer, &QTimer::timeout, this, &CanvasEntityRenderer::onTimeout);
+    _testTimer.start();
 }
 
 CanvasEntityRenderer::~CanvasEntityRenderer() { }
+
+void CanvasEntityRenderer::onTimeout() {
+    gpu::Byte pixels[256 * 256 * 4];
+
+    // XOR placeholder texture
+    for (int x = 0; x < 256; x++) {
+        for (int y = 0; y < 256; y++) {
+            pixels[(y * 256 * 4) + (x * 4) + 0] = ((x + _ticks) ^ (y + _ticks));
+            pixels[(y * 256 * 4) + (x * 4) + 1] = ((x + _ticks) ^ (y + _ticks));
+            pixels[(y * 256 * 4) + (x * 4) + 2] = ((x + _ticks) ^ (y + _ticks));
+            pixels[(y * 256 * 4) + (x * 4) + 3] = 255;
+        }
+    }
+
+    _texture->assignStoredMip(0, 256 * 256 * 4, pixels);
+
+    _ticks += 1;
+    qDebug("onTimeout: _ticks = %d", _ticks);
+}
diff --git a/libraries/entities-renderer/src/RenderableCanvasEntityItem.h b/libraries/entities-renderer/src/RenderableCanvasEntityItem.h
index 050a6be02f..fef1cdb721 100644
--- a/libraries/entities-renderer/src/RenderableCanvasEntityItem.h
+++ b/libraries/entities-renderer/src/RenderableCanvasEntityItem.h
@@ -34,6 +34,10 @@ protected:
 
 private:
     gpu::TexturePointer _texture;
+
+    int _ticks = 0;
+    QTimer _testTimer;
+    void onTimeout();
 };
 
 } }
diff --git a/libraries/entities-renderer/src/RenderableEntityItem.cpp b/libraries/entities-renderer/src/RenderableEntityItem.cpp
index 7ca3a5c341..a3e4cbb105 100644
--- a/libraries/entities-renderer/src/RenderableEntityItem.cpp
+++ b/libraries/entities-renderer/src/RenderableEntityItem.cpp
@@ -31,6 +31,7 @@
 #include "RenderableLightEntityItem.h"
 #include "RenderableZoneEntityItem.h"
 #include "RenderableMaterialEntityItem.h"
+#include "RenderableCanvasEntityItem.h"
 
 #include "RenderPipelines.h"
 
@@ -433,6 +434,10 @@ EntityRenderer::Pointer EntityRenderer::addToScene(EntityTreeRenderer& renderer,
             result = make_renderer<MaterialEntityRenderer>(entity);
             break;
 
+        case Type::Canvas:
+            result = make_renderer<CanvasEntityRenderer>(entity);
+            break;
+
         default:
             break;
     }