From 11d93e1633249cd030e0a0321d2fe4dccc4ebc2e Mon Sep 17 00:00:00 2001
From: Kai Blaschke <kai.blaschke@kb-dev.net>
Date: Tue, 30 Sep 2025 19:28:26 +0200
Subject: [PATCH] Use Mesh class in classic post-processing effects

---
 src/libprojectM/MilkdropPreset/Filters.cpp | 53 +++++++---------------
 src/libprojectM/MilkdropPreset/Filters.hpp |  8 ++--
 2 files changed, 21 insertions(+), 40 deletions(-)

diff --git a/src/libprojectM/MilkdropPreset/Filters.cpp b/src/libprojectM/MilkdropPreset/Filters.cpp
index 472a0e70b..09d472bfa 100644
--- a/src/libprojectM/MilkdropPreset/Filters.cpp
+++ b/src/libprojectM/MilkdropPreset/Filters.cpp
@@ -4,18 +4,11 @@ namespace libprojectM {
 namespace MilkdropPreset {
 
 Filters::Filters(const PresetState& presetState)
-    : RenderItem()
-    , m_presetState(presetState)
+    : m_presetState(presetState)
+    , m_filterMesh(Renderer::VertexBufferUsage::StaticDraw)
 {
-    RenderItem::Init();
-}
-
-void Filters::InitVertexAttrib()
-{
-    glEnableVertexAttribArray(0);
-    glDisableVertexAttribArray(1);
-
-    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(Point), reinterpret_cast<void*>(offsetof(Point, x)));
+    m_filterMesh.SetRenderPrimitiveType(Renderer::Mesh::PrimitiveType::TriangleStrip);
+    m_filterMesh.SetVertexCount(4);
 }
 
 void Filters::Draw()
@@ -33,7 +26,6 @@ void Filters::Draw()
     shader->Bind();
     shader->SetUniformMat4x4("vertex_transformation", PresetState::orthogonalProjection);
 
-    glBindVertexArray(m_vaoID);
     glVertexAttrib4f(1, 1.0, 1.0, 1.0, 1.0);
 
     if (m_presetState.brighten)
@@ -53,8 +45,7 @@ void Filters::Draw()
         Invert();
     }
 
-    glBindVertexArray(0);
-
+    Renderer::Mesh::Unbind();
     Renderer::Shader::Unbind();
 
     glDisable(GL_BLEND);
@@ -64,31 +55,31 @@ void Filters::Draw()
 void Filters::Brighten()
 {
     glBlendFunc(GL_ONE_MINUS_DST_COLOR, GL_ZERO);
-    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+    m_filterMesh.Draw();
     glBlendFunc(GL_ZERO, GL_DST_COLOR);
-    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+    m_filterMesh.Draw();
     glBlendFunc(GL_ONE_MINUS_DST_COLOR, GL_ZERO);
-    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+    m_filterMesh.Draw();
 }
 
 void Filters::Darken()
 {
     glBlendFunc(GL_ZERO, GL_DST_COLOR);
-    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+    m_filterMesh.Draw();
 }
 
 void Filters::Solarize()
 {
     glBlendFunc(GL_ZERO, GL_ONE_MINUS_DST_COLOR);
-    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+    m_filterMesh.Draw();
     glBlendFunc(GL_DST_COLOR, GL_ONE);
-    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+    m_filterMesh.Draw();
 }
 
 void Filters::Invert()
 {
     glBlendFunc(GL_ONE_MINUS_DST_COLOR, GL_ZERO);
-    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+    m_filterMesh.Draw();
 }
 
 void Filters::UpdateMesh()
@@ -102,24 +93,14 @@ void Filters::UpdateMesh()
     m_viewportWidth = m_presetState.renderContext.viewportSizeX;
     m_viewportHeight = m_presetState.renderContext.viewportSizeY;
 
-    std::array<RenderItem::Point, 4> points;
-
     float const fOnePlusInvWidth = 1.0f + 1.0f / static_cast<float>(m_viewportWidth);
     float const fOnePlusInvHeight = 1.0f + 1.0f / static_cast<float>(m_viewportHeight);
-    points[0].x = -fOnePlusInvWidth;
-    points[1].x = fOnePlusInvWidth;
-    points[2].x = -fOnePlusInvWidth;
-    points[3].x = fOnePlusInvWidth;
-    points[0].y = fOnePlusInvHeight;
-    points[1].y = fOnePlusInvHeight;
-    points[2].y = -fOnePlusInvHeight;
-    points[3].y = -fOnePlusInvHeight;
+    m_filterMesh.Vertices().Set({{-fOnePlusInvWidth, fOnePlusInvHeight},
+                                 {fOnePlusInvWidth, fOnePlusInvHeight},
+                                 {-fOnePlusInvWidth, -fOnePlusInvHeight},
+                                 {fOnePlusInvWidth, -fOnePlusInvHeight}});
 
-    glBindVertexArray(m_vaoID);
-    glBindBuffer(GL_ARRAY_BUFFER, m_vboID);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(points), points.data(), GL_STATIC_DRAW);
-    glBindVertexArray(0);
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    m_filterMesh.Update();
 }
 
 } // namespace MilkdropPreset
diff --git a/src/libprojectM/MilkdropPreset/Filters.hpp b/src/libprojectM/MilkdropPreset/Filters.hpp
index c00084654..1decfcafb 100644
--- a/src/libprojectM/MilkdropPreset/Filters.hpp
+++ b/src/libprojectM/MilkdropPreset/Filters.hpp
@@ -2,7 +2,7 @@
 
 #include "PresetState.hpp"
 
-#include <Renderer/RenderItem.hpp>
+#include <Renderer/Mesh.hpp>
 
 namespace libprojectM {
 namespace MilkdropPreset {
@@ -10,14 +10,12 @@ namespace MilkdropPreset {
 /**
  * @brief Classic Milkdrop 1 postprocessing effects.
  */
-class Filters : public Renderer::RenderItem
+class Filters
 {
 public:
     Filters() = delete;
     explicit Filters(const PresetState& presetState);
 
-    void InitVertexAttrib();
-
     /**
      * @brief Applies the configured filters to the current output.
      */
@@ -48,6 +46,8 @@ private:
 
     const PresetState& m_presetState; //!< The global preset state.
 
+    Renderer::Mesh m_filterMesh;
+
     int m_viewportWidth{}; //!< Last known viewport width
     int m_viewportHeight{}; //!< Last known viewport height
 };