[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/texture_buffer.c

@@ -19,6 +19,7 @@
  */
 
 #include "texture_buffer.h"
+#include "state.h"
 
 #include "egldebug.h"
 
@@ -35,7 +36,10 @@ static void egl_texBuffer_cleanup(TextureBuffer * this)
   egl_texUtilFreeBuffers(this->buf, this->texCount);
 
   if (this->tex[0])
+  {
     glDeleteTextures(this->texCount, this->tex);
+    egl_stateInvalidateShared();
+  }
 
   for (int i = 0; i < EGL_TEX_BUFFER_MAX; ++i)
   {
@@ -89,9 +93,10 @@ bool egl_texBufferSetup(EGL_Texture * texture, const EGL_TexSetup * setup)
   egl_texBuffer_cleanup(this);
 
   glGenTextures(this->texCount, this->tex);
+  egl_stateBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
   for(int i = 0; i < this->texCount; ++i)
   {
-    glBindTexture(GL_TEXTURE_2D, this->tex[i]);
+    egl_stateBindTexture(0, GL_TEXTURE_2D, this->tex[i]);
     glTexImage2D(GL_TEXTURE_2D,
         0,
         texture->format.intFormat,
@@ -103,7 +108,6 @@ bool egl_texBufferSetup(EGL_Texture * texture, const EGL_TexSetup * setup)
         NULL);
   }
 
-  glBindTexture(GL_TEXTURE_2D, 0);
   this->bufIndex = 0;
   this->rIndex = -1;
 
@@ -118,7 +122,8 @@ static bool egl_texBufferUpdate(EGL_Texture * texture, const EGL_TexUpdate * upd
   TextureBuffer * this = UPCAST(TextureBuffer, texture);
   DEBUG_ASSERT(update->type == EGL_TEXTYPE_BUFFER);
 
-  glBindTexture(GL_TEXTURE_2D, this->tex[0]);
+  egl_stateBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+  egl_stateBindTexture(0, GL_TEXTURE_2D, this->tex[0]);
   glPixelStorei(GL_UNPACK_ROW_LENGTH, update->stride);
   glTexSubImage2D(GL_TEXTURE_2D,
       0,
@@ -129,8 +134,6 @@ static bool egl_texBufferUpdate(EGL_Texture * texture, const EGL_TexUpdate * upd
       texture->format.format,
       texture->format.dataType,
       update->buffer);
-  glBindTexture(GL_TEXTURE_2D, 0);
-
   return true;
 }
 
@@ -292,8 +295,8 @@ EGL_TexStatus egl_texBufferStreamProcess(EGL_Texture * texture)
   if (!keepLocked)
     LG_UNLOCK(this->copyLock);
 
-  glBindBuffer(GL_PIXEL_UNPACK_BUFFER, buffer->pbo);
-  glBindTexture(GL_TEXTURE_2D, tex);
+  egl_stateBindBuffer(GL_PIXEL_UNPACK_BUFFER, buffer->pbo);
+  egl_stateBindTexture(0, GL_TEXTURE_2D, tex);
 
   glPixelStorei(GL_UNPACK_ROW_LENGTH, texture->format.stride);
   glTexSubImage2D(GL_TEXTURE_2D,
@@ -303,9 +306,6 @@ EGL_TexStatus egl_texBufferStreamProcess(EGL_Texture * texture)
       texture->format.format,
       texture->format.dataType,
       (const void *)0);
-  glBindTexture(GL_TEXTURE_2D, 0);
-  glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
-
   this->sync[index] = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
   if (unlikely(!this->sync[index]))
   {
@@ -348,7 +348,7 @@ EGL_TexStatus egl_texBufferBind(EGL_Texture * texture)
   if ((status = texture->ops.get(texture, &tex, NULL)) != EGL_TEX_STATUS_OK)
     return status;
 
-  glBindTexture(GL_TEXTURE_2D, tex);
+  egl_stateBindTexture(0, GL_TEXTURE_2D, tex);
   return EGL_TEX_STATUS_OK;
 }