From 1fcdcc87257e3d87aec535fdc35a6655a35ca279 Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Sat, 21 May 2022 21:21:16 +1000
Subject: [PATCH] [client] egl: allow for partial texture updates

---
 client/renderers/EGL/texture.c        | 49 +++++++++++++++++++++++++--
 client/renderers/EGL/texture.h        | 10 ++++++
 client/renderers/EGL/texture_buffer.c | 10 +++---
 common/include/common/util.h          |  4 +++
 4 files changed, 67 insertions(+), 6 deletions(-)

diff --git a/client/renderers/EGL/texture.c b/client/renderers/EGL/texture.c
index 06af7c06..b5e89e71 100644
--- a/client/renderers/EGL/texture.c
+++ b/client/renderers/EGL/texture.c
@@ -108,6 +108,39 @@ bool egl_textureUpdate(EGL_Texture * this, const uint8_t * buffer)
   const struct EGL_TexUpdate update =
   {
     .type   = EGL_TEXTYPE_BUFFER,
+    .x      = 0,
+    .y      = 0,
+    .width  = this->format.width,
+    .height = this->format.height,
+    .pitch  = this->format.pitch,
+    .stride = this->format.stride,
+    .buffer = buffer
+  };
+
+  return this->ops.update(this, &update);
+}
+
+bool egl_textureUpdateRect(EGL_Texture * this,
+    int x, int y, int width, int height, int stride,
+    const uint8_t * buffer)
+{
+  x      = clamp(x     , 0, this->format.width     );
+  y      = clamp(y     , 0, this->format.height    );
+  width  = clamp(width , x, this->format.width  - x);
+  height = clamp(height, y, this->format.height - y);
+
+  if (!width || !height)
+    return true;
+
+  const struct EGL_TexUpdate update =
+  {
+    .type   = EGL_TEXTYPE_BUFFER,
+    .x      = x,
+    .y      = y,
+    .width  = width,
+    .height = height,
+    .pitch  = stride / (stride / width),
+    .stride = stride,
     .buffer = buffer
   };
 
@@ -121,6 +154,12 @@ bool egl_textureUpdateFromFrame(EGL_Texture * this,
   const struct EGL_TexUpdate update =
   {
     .type      = EGL_TEXTYPE_FRAMEBUFFER,
+    .x         = 0,
+    .y         = 0,
+    .width     = this->format.width,
+    .height    = this->format.height,
+    .pitch     = this->format.pitch,
+    .stride    = this->format.stride,
     .frame     = frame,
     .rects     = damageRects,
     .rectCount = damageRectsCount,
@@ -134,8 +173,14 @@ bool egl_textureUpdateFromDMA(EGL_Texture * this,
 {
   const struct EGL_TexUpdate update =
   {
-    .type  = EGL_TEXTYPE_DMABUF,
-    .dmaFD = dmaFd
+    .type   = EGL_TEXTYPE_DMABUF,
+    .x      = 0,
+    .y      = 0,
+    .width  = this->format.width,
+    .height = this->format.height,
+    .pitch  = this->format.pitch,
+    .stride = this->format.stride,
+    .dmaFD  = dmaFd
   };
 
   /* wait for completion */
diff --git a/client/renderers/EGL/texture.h b/client/renderers/EGL/texture.h
index 53d709b4..3f251a84 100644
--- a/client/renderers/EGL/texture.h
+++ b/client/renderers/EGL/texture.h
@@ -42,6 +42,12 @@ typedef struct EGL_TexUpdate
   /* the type of this update */
   EGL_TexType type;
 
+  int x, y, width, height;
+
+  //pitch  = row length in pixels
+  //stride = row length in bytes
+  int pitch, stride;
+
   union
   {
     /* EGL_TEXTURE_BUFFER */
@@ -102,6 +108,10 @@ bool egl_textureSetup(EGL_Texture * texture, enum EGL_PixelFormat pixFmt,
 
 bool egl_textureUpdate(EGL_Texture * texture, const uint8_t * buffer);
 
+bool egl_textureUpdateRect(EGL_Texture * texture,
+    int x, int y, int width, int height, int stride,
+    const uint8_t * buffer);
+
 bool egl_textureUpdateFromFrame(EGL_Texture * texture,
     const FrameBuffer * frame, const FrameDamageRect * damageRects,
     int damageRectsCount);
diff --git a/client/renderers/EGL/texture_buffer.c b/client/renderers/EGL/texture_buffer.c
index 2ee83223..5f7b497b 100644
--- a/client/renderers/EGL/texture_buffer.c
+++ b/client/renderers/EGL/texture_buffer.c
@@ -111,11 +111,13 @@ static bool egl_texBufferUpdate(EGL_Texture * texture, const EGL_TexUpdate * upd
   DEBUG_ASSERT(update->type == EGL_TEXTYPE_BUFFER);
 
   glBindTexture(GL_TEXTURE_2D, this->tex[0]);
-  glPixelStorei(GL_UNPACK_ROW_LENGTH, texture->format.pitch);
+  glPixelStorei(GL_UNPACK_ROW_LENGTH, update->pitch);
   glTexSubImage2D(GL_TEXTURE_2D,
-      0, 0, 0,
-      texture->format.width,
-      texture->format.height,
+      0,
+      update->x,
+      update->y,
+      update->width,
+      update->height,
       texture->format.format,
       texture->format.dataType,
       update->buffer);
diff --git a/common/include/common/util.h b/common/include/common/util.h
index 0f5a2fe4..bb21fecc 100644
--- a/common/include/common/util.h
+++ b/common/include/common/util.h
@@ -31,6 +31,10 @@
     _a > _b ? _a : _b; })
 #endif
 
+#ifndef clamp
+#define clamp(v,a,b) min(max(v, a), b)
+#endif
+
 #define UPCAST(type, x) \
   (type *)((uintptr_t)(x) - offsetof(type, base))