renderer: add transformers

src/Window.hpp

@@ -32,6 +32,8 @@ enum eGroupRules
     GROUP_OVERRIDE    = 1 << 6, // Override other rules
 };
 
+class IWindowTransformer;
+
 template <typename T>
 class CWindowOverridableVar {
   public:
@@ -290,6 +292,9 @@ class CWindow {
     SWindowSpecialRenderData    m_sSpecialRenderData;
     SWindowAdditionalConfigData m_sAdditionalConfigData;
 
+    // Transformers
+    std::vector<std::unique_ptr<IWindowTransformer>> m_vTransformers;
+
     // for alpha
     CAnimatedVariable m_fActiveInactiveAlpha;
 

src/render/OpenGL.cpp

@@ -128,10 +128,12 @@ void CHyprOpenGLImpl::begin(CMonitor* pMonitor, CRegion* pDamage, bool fake) {
         m_RenderData.pCurrentMonData->primaryFB.m_pStencilTex    = &m_RenderData.pCurrentMonData->stencilTex;
         m_RenderData.pCurrentMonData->mirrorFB.m_pStencilTex     = &m_RenderData.pCurrentMonData->stencilTex;
         m_RenderData.pCurrentMonData->mirrorSwapFB.m_pStencilTex = &m_RenderData.pCurrentMonData->stencilTex;
+        m_RenderData.pCurrentMonData->offMainFB.m_pStencilTex    = &m_RenderData.pCurrentMonData->stencilTex;
 
         m_RenderData.pCurrentMonData->primaryFB.alloc(pMonitor->vecPixelSize.x, pMonitor->vecPixelSize.y);
         m_RenderData.pCurrentMonData->mirrorFB.alloc(pMonitor->vecPixelSize.x, pMonitor->vecPixelSize.y);
         m_RenderData.pCurrentMonData->mirrorSwapFB.alloc(pMonitor->vecPixelSize.x, pMonitor->vecPixelSize.y);
+        m_RenderData.pCurrentMonData->offMainFB.alloc(pMonitor->vecPixelSize.x, pMonitor->vecPixelSize.y);
 
         createBGTextureForMonitor(pMonitor);
     }
@@ -149,6 +151,8 @@ void CHyprOpenGLImpl::begin(CMonitor* pMonitor, CRegion* pDamage, bool fake) {
 
     m_bFakeFrame = fake;
 
+    m_RenderData.currentFB = &m_RenderData.pCurrentMonData->primaryFB;
+
     if (m_bReloadScreenShader) {
         m_bReloadScreenShader = false;
         applyScreenShader(g_pConfigManager->getString("decoration:screen_shader"));
@@ -1892,6 +1896,7 @@ void CHyprOpenGLImpl::destroyMonitorResources(CMonitor* pMonitor) {
     g_pHyprOpenGL->m_mMonitorRenderResources[pMonitor].mirrorSwapFB.release();
     g_pHyprOpenGL->m_mMonitorRenderResources[pMonitor].monitorMirrorFB.release();
     g_pHyprOpenGL->m_mMonitorRenderResources[pMonitor].blurFB.release();
+    g_pHyprOpenGL->m_mMonitorRenderResources[pMonitor].offMainFB.release();
     g_pHyprOpenGL->m_mMonitorRenderResources[pMonitor].stencilTex.destroyTexture();
     g_pHyprOpenGL->m_mMonitorBGTextures[pMonitor].destroyTexture();
     g_pHyprOpenGL->m_mMonitorRenderResources.erase(pMonitor);
@@ -1914,3 +1919,19 @@ void CHyprOpenGLImpl::setMatrixScaleTranslate(const Vector2D& translate, const f
 void CHyprOpenGLImpl::restoreMatrix() {
     memcpy(m_RenderData.projection, m_RenderData.savedProjection, 9 * sizeof(float));
 }
+
+void CHyprOpenGLImpl::bindOffMain() {
+    m_RenderData.pCurrentMonData->offMainFB.bind();
+    clear(CColor(0, 0, 0, 0));
+    m_RenderData.currentFB = &m_RenderData.pCurrentMonData->offMainFB;
+}
+
+void CHyprOpenGLImpl::renderOffToMain(CFramebuffer* off) {
+    wlr_box monbox = {0, 0, m_RenderData.pMonitor->vecTransformedSize.x, m_RenderData.pMonitor->vecTransformedSize.y};
+    renderTexturePrimitive(off->m_cTex, &monbox);
+}
+
+void CHyprOpenGLImpl::bindBackOnMain() {
+    m_RenderData.pCurrentMonData->primaryFB.bind();
+    m_RenderData.currentFB = &m_RenderData.pCurrentMonData->primaryFB;
+}

src/render/OpenGL.hpp

@@ -13,6 +13,7 @@
 #include "Shader.hpp"
 #include "Texture.hpp"
 #include "Framebuffer.hpp"
+#include "Transformer.hpp"
 
 #include "../debug/TracyDefines.hpp"
 
@@ -41,6 +42,7 @@ struct SMonitorRenderData {
     CFramebuffer primaryFB;
     CFramebuffer mirrorFB;     // these are used for some effects,
     CFramebuffer mirrorSwapFB; // etc
+    CFramebuffer offMainFB;
 
     CFramebuffer monitorMirrorFB; // used for mirroring outputs
 
@@ -75,6 +77,7 @@ struct SCurrentRenderData {
     float               savedProjection[9];
 
     SMonitorRenderData* pCurrentMonData = nullptr;
+    CFramebuffer*       currentFB       = nullptr;
 
     CRegion             damage;
 
@@ -142,6 +145,10 @@ class CHyprOpenGLImpl {
 
     void               applyScreenShader(const std::string& path);
 
+    void               bindOffMain();
+    void               renderOffToMain(CFramebuffer* off);
+    void               bindBackOnMain();
+
     SCurrentRenderData m_RenderData;
 
     GLint              m_iCurrentOutputFb = 0;

src/render/Renderer.cpp

@@ -406,6 +406,12 @@ void CHyprRenderer::renderWindow(CWindow* pWindow, CMonitor* pMonitor, timespec*
 
     // render window decorations first, if not fullscreen full
     if (mode == RENDER_PASS_ALL || mode == RENDER_PASS_MAIN) {
+
+        const bool TRANSFORMERSPRESENT = !pWindow->m_vTransformers.empty();
+
+        if (TRANSFORMERSPRESENT)
+            g_pHyprOpenGL->bindOffMain();
+
         if (!pWindow->m_bIsFullscreen || PWORKSPACE->m_efFullscreenMode != FULLSCREEN_FULL)
             for (auto& wd : pWindow->m_dWindowDecorations)
                 wd->draw(pMonitor, renderdata.alpha * renderdata.fadeAlpha, offset);
@@ -443,6 +449,17 @@ void CHyprRenderer::renderWindow(CWindow* pWindow, CMonitor* pMonitor, timespec*
                 g_pHyprOpenGL->renderBorder(&windowBox, g_pHyprOpenGL->m_pCurrentWindow->m_cRealBorderColorPrevious, renderdata.rounding, borderSize, a2);
             }
         }
+
+        if (TRANSFORMERSPRESENT) {
+
+            CFramebuffer* last = g_pHyprOpenGL->m_RenderData.currentFB;
+            for (auto& t : pWindow->m_vTransformers) {
+                last = t->transform(last);
+            }
+
+            g_pHyprOpenGL->bindBackOnMain();
+            g_pHyprOpenGL->renderOffToMain(last);
+        }
     }
 
     if (mode == RENDER_PASS_ALL || mode == RENDER_PASS_POPUP) {

src/render/Transformer.cpp

@@ -0,0 +1 @@
+#include "Transformer.hpp"

src/render/Transformer.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+#include "Framebuffer.hpp"
+
+// A window transformer can be attached to a window.
+// If any is attached, Hyprland will render the window to a separate fb, then call the transform() func with it,
+// and finally render it back to the main fb after all transformers pass.
+class IWindowTransformer {
+  public:
+    // called by Hyprland. For more data about what is being rendered, inspect render data.
+    // returns the out fb.
+    virtual CFramebuffer* transform(CFramebuffer* in) = 0;
+};