[client] egl: cache renderer GL state

Track context-local GL bindings to avoid redundant program, framebuffer,
buffer, texture, sampler, viewport, blend, and scissor state changes.

Invalidate the cache across context switches, ImGui rendering, and
shared object changes. Preserve CPU-backed texture upload correctness by
explicitly clearing pixel unpack buffer bindings where required.

This reduces hot-path driver overhead without adding waits or GPU
synchronization.

client/renderers/EGL/egl.c

@@ -43,6 +43,7 @@
 #include "egl_dynprocs.h"
 #include "model.h"
 #include "shader.h"
+#include "state.h"
 #include "damage.h"
 #include "desktop.h"
 #include "cursor.h"
@@ -298,7 +299,10 @@ static void egl_deinitialize(LG_Renderer * renderer)
   struct Inst * this = UPCAST(struct Inst, renderer);
 
   if (this->imgui)
+  {
     ImGui_ImplOpenGL3_Shutdown();
+    egl_stateInvalidate();
+  }
 
   ringbuffer_free(&this->importTimings);
 
@@ -483,13 +487,14 @@ static void egl_update_scale_type(struct Inst * this)
 
 void egl_resetViewport(EGL * this)
 {
-  glViewport(0, 0, this->width, this->height);
+  egl_stateViewport(0, 0, this->width, this->height);
 }
 
 static void egl_onResize(LG_Renderer * renderer, const int width, const int height, const double scale,
     const LG_RendererRect destRect, LG_RendererRotate rotate)
 {
   struct Inst * this = UPCAST(struct Inst, renderer);
+  egl_stateCheckShared();
 
   this->width   = width * scale;
   this->height  = height * scale;
@@ -501,7 +506,7 @@ static void egl_onResize(LG_Renderer * renderer, const int width, const int heig
   this->destRect.w = destRect.w * scale;
   this->destRect.h = destRect.h * scale;
 
-  glViewport(0, 0, this->width, this->height);
+  egl_stateViewport(0, 0, this->width, this->height);
 
   if (destRect.valid)
   {
@@ -540,6 +545,7 @@ static void egl_onResize(LG_Renderer * renderer, const int width, const int heig
   ImGui_ImplOpenGL3_Shutdown();
   ImGui_ImplOpenGL3_Init("#version 300 es");
   ImGui_ImplOpenGL3_NewFrame();
+  egl_stateInvalidate();
 
   egl_damageResize(this->damage, this->translateX, this->translateY, this->scaleX, this->scaleY);
   egl_desktopResize(this->desktop, this->width, this->height);
@@ -602,8 +608,12 @@ static bool egl_onFrameFormat(LG_Renderer * renderer, const LG_RendererFormat fo
       DEBUG_ERROR("Failed to make the frame context current");
       return false;
     }
+
+    egl_stateInvalidate();
   }
 
+  egl_stateCheckShared();
+
   if (likely(this->scalePointer))
   {
     float scale = max(1.0f, (float)format.screenWidth / this->width);
@@ -649,6 +659,7 @@ static bool egl_onFrame(LG_Renderer * renderer, const FrameBuffer * frame, int d
     const FrameDamageRect * damageRects, int damageRectsCount)
 {
   struct Inst * this = UPCAST(struct Inst, renderer);
+  egl_stateCheckShared();
 
   uint64_t start = nanotime();
   if (unlikely(!egl_desktopUpdate(
@@ -922,6 +933,7 @@ static bool egl_renderStartup(LG_Renderer * renderer, bool useDMA)
   }
 
   eglMakeCurrent(this->display, this->surface, this->surface, this->context);
+  egl_stateInvalidate();
   const char * gl_exts = (const char *)glGetString(GL_EXTENSIONS);
   if (!gl_exts)
   {
@@ -1038,6 +1050,7 @@ static bool egl_renderStartup(LG_Renderer * renderer, bool useDMA)
     DEBUG_ERROR("Failed to initialize ImGui");
     return false;
   }
+  egl_stateInvalidate();
 
   app_overlayConfigRegister("EGL", egl_configUI, this);
 
@@ -1067,7 +1080,7 @@ inline static void renderLetterBox(struct Inst * this)
   if (hLB || vLB)
   {
     glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
-    glEnable(GL_SCISSOR_TEST);
+    egl_stateScissor(true);
 
     if (hLB)
     {
@@ -1094,7 +1107,7 @@ inline static void renderLetterBox(struct Inst * this)
       glClear(GL_COLOR_BUFFER_BIT);
     }
 
-    glDisable(GL_SCISSOR_TEST);
+    egl_stateScissor(false);
   }
 }
 
@@ -1103,6 +1116,7 @@ static bool egl_render(LG_Renderer * renderer, LG_RendererRotate rotate,
     void (*preSwap)(void * udata), void * udata)
 {
   struct Inst * this = UPCAST(struct Inst, renderer);
+  egl_stateCheckShared();
   EGLint bufferAge   = egl_bufferAge(this);
   bool renderAll     = invalidateWindow || this->hadOverlay ||
                        bufferAge <= 0 || bufferAge > MAX_BUFFER_AGE ||
@@ -1213,6 +1227,7 @@ static bool egl_render(LG_Renderer * renderer, LG_RendererRotate rotate,
 
     ImGui_ImplOpenGL3_NewFrame();
     ImGui_ImplOpenGL3_RenderDrawData(igGetDrawData());
+    egl_stateInvalidate();
 
     for (int i = 0; i < damageIdx; ++i)
       damage[i].y = this->height - damage[i].y - damage[i].h;
@@ -1268,9 +1283,12 @@ static bool egl_render(LG_Renderer * renderer, LG_RendererRotate rotate,
 static void * egl_createTexture(LG_Renderer * renderer,
   int width, int height, uint8_t * data)
 {
+  egl_stateCheckShared();
+
   GLuint tex;
   glGenTextures(1, &tex);
-  glBindTexture(GL_TEXTURE_2D, tex);
+  egl_stateBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+  egl_stateBindTexture(0, GL_TEXTURE_2D, tex);
 
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
@@ -1289,8 +1307,6 @@ static void * egl_createTexture(LG_Renderer * renderer,
       GL_UNSIGNED_BYTE,
       data);
 
-  glBindTexture(GL_TEXTURE_2D, 0);
-
   return (void*)(intptr_t)tex;
 }
 
@@ -1298,11 +1314,13 @@ static void egl_freeTexture(LG_Renderer * renderer, void * texture)
 {
   GLuint tex = (GLuint)(intptr_t)texture;
   glDeleteTextures(1, &tex);
+  egl_stateInvalidateShared();
 }
 
 static void egl_spiceConfigure(LG_Renderer * renderer, int width, int height)
 {
   struct Inst * this = UPCAST(struct Inst, renderer);
+  egl_stateCheckShared();
   this->spiceWidth   = width;
   this->spiceHeight  = height;
   egl_desktopSpiceConfigure(this->desktop, width, height);
@@ -1312,6 +1330,7 @@ static void egl_spiceDrawFill(LG_Renderer * renderer, int x, int y, int width,
     int height, uint32_t color)
 {
   struct Inst * this = UPCAST(struct Inst, renderer);
+  egl_stateCheckShared();
   egl_desktopSpiceDrawFill(this->desktop, x, y, width, height, color);
 }
 
@@ -1319,6 +1338,7 @@ static void egl_spiceDrawBitmap(LG_Renderer * renderer, int x, int y, int width,
     int height, int stride, uint8_t * data, bool topDown)
 {
   struct Inst * this = UPCAST(struct Inst, renderer);
+  egl_stateCheckShared();
   egl_desktopSpiceDrawBitmap(this->desktop, x, y, width, height, stride,
       data, topDown);
 }