From cbeae46c0b0258fd1be8760d9a6a38e7706e9862 Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Fri, 15 Jan 2021 13:13:39 +1100
Subject: [PATCH] [client] egl: move rotation into the fragment shader

---
 client/renderers/EGL/cursor.c               | 37 ++------------------
 client/renderers/EGL/shader/cursor.vert     | 38 +++++++++++++++------
 client/renderers/EGL/shader/cursor_rgb.frag | 25 ++------------
 3 files changed, 32 insertions(+), 68 deletions(-)

diff --git a/client/renderers/EGL/cursor.c b/client/renderers/EGL/cursor.c
index 2fd0a8fa..d7dc5571 100644
--- a/client/renderers/EGL/cursor.c
+++ b/client/renderers/EGL/cursor.c
@@ -97,48 +97,15 @@ static bool egl_cursor_tex_init(struct CursorTex * t,
 
 static inline void egl_cursor_tex_uniforms(EGL_Cursor * cursor, struct CursorTex * t, bool mono)
 {
-  float x, y, w, h;
-
-  switch(cursor->rotate)
-  {
-    case LG_ROTATE_UP:
-      x =  cursor->x;
-      y =  cursor->y;
-      w =  cursor->w;
-      h =  cursor->h;
-      break;
-
-    case LG_ROTATE_DOWN:
-      x = -cursor->x;
-      y = -cursor->y;
-      w =  cursor->w;
-      h =  cursor->h;
-      break;
-
-    case LG_ROTATE_LEFT:
-      x =  cursor->y;
-      y = -cursor->x;
-      w =  cursor->h;
-      h =  cursor->w;
-      break;
-
-    case LG_ROTATE_RIGHT:
-      x = -cursor->y;
-      y =  cursor->x;
-      w =  cursor->h;
-      h =  cursor->w;
-      break;
-  }
-
   if (mono)
   {
-    glUniform4f(t->uMousePos, x, y, w, h / 2);
+    glUniform4f(t->uMousePos, cursor->x, cursor->y, cursor->w, cursor->h / 2);
     glUniform1i(t->uRotate  , cursor->rotate);
     glUniform1i(t->uCBMode  , cursor->cbMode);
   }
   else
   {
-    glUniform4f(t->uMousePos, x, y, w, h);
+    glUniform4f(t->uMousePos, cursor->x, cursor->y, cursor->w, cursor->h);
     glUniform1i(t->uRotate  , cursor->rotate);
     glUniform1i(t->uCBMode  , cursor->cbMode);
   }
diff --git a/client/renderers/EGL/shader/cursor.vert b/client/renderers/EGL/shader/cursor.vert
index 4a289fb5..63866a97 100644
--- a/client/renderers/EGL/shader/cursor.vert
+++ b/client/renderers/EGL/shader/cursor.vert
@@ -4,22 +4,40 @@ layout(location = 0) in vec3 vertexPosition_modelspace;
 layout(location = 1) in vec2 vertexUV;
 
 uniform vec4 mouse;
+uniform lowp int rotate;
 
 out highp vec2 uv;
 
 void main()
 {
-  gl_Position.xyz = vertexPosition_modelspace;
-  gl_Position.w   = 1.0;
+  vec2 muv = vertexPosition_modelspace.xy;
+  muv.x += 1.0f;
+  muv.y -= 1.0f;
+  muv.x *= mouse.z;
+  muv.y *= mouse.w;
+  muv.x += mouse.x;
+  muv.y -= mouse.y;
 
-  gl_Position.x += 1.0f;
-  gl_Position.y -= 1.0f;
-
-  gl_Position.x *= mouse.z;
-  gl_Position.y *= mouse.w;
-
-  gl_Position.x += mouse.x;
-  gl_Position.y -= mouse.y;
+  if (rotate == 0) // up
+  {
+    gl_Position.xy = muv;
+  }
+  else if (rotate == 1) // down
+  {
+    gl_Position.x = -muv.x;
+    gl_Position.y = -muv.y;
+  }
+  else if (rotate == 2) // left
+  {
+    gl_Position.x = -muv.y;
+    gl_Position.y =  muv.x;
+  }
+  else if (rotate == 3) // right
+  {
+    gl_Position.x =  muv.y;
+    gl_Position.y = -muv.x;
+  }
 
+  gl_Position.w = 1.0;
   uv = vertexUV;
 }
diff --git a/client/renderers/EGL/shader/cursor_rgb.frag b/client/renderers/EGL/shader/cursor_rgb.frag
index 2c4c6e2b..8b0ed763 100644
--- a/client/renderers/EGL/shader/cursor_rgb.frag
+++ b/client/renderers/EGL/shader/cursor_rgb.frag
@@ -2,36 +2,15 @@
 
 in  highp vec2 uv;
 out highp vec4 color;
-uniform int rotate;
 
 uniform sampler2D sampler1;
 
+uniform lowp int rotate;
 uniform int cbMode;
 
 void main()
 {
-  highp vec2 ruv;
-  if (rotate == 0) // up
-  {
-    ruv = uv;
-  }
-  else if (rotate == 1) // down
-  {
-    ruv.x = -uv.x + 1.0f;
-    ruv.y = -uv.y + 1.0f;
-  }
-  else if (rotate == 2) // left
-  {
-    ruv.x = -uv.y + 1.0f;
-    ruv.y =  uv.x;
-  }
-  else if (rotate == 3) // right
-  {
-    ruv.x =  uv.y;
-    ruv.y = -uv.x + 1.0f;
-  }
-
-  color = texture(sampler1, ruv);
+  color = texture(sampler1, uv);
 
   if (cbMode > 0)
   {