From fe519a93f2638c01662b48aa7f25fcbebf19c544 Mon Sep 17 00:00:00 2001
From: ppodds <oscar20020629@gmail.com>
Date: Fri, 31 Dec 2021 03:16:46 +0800
Subject: [PATCH] Fix: enable O2 when building solution cause the do-nothing
 loop be optimized

---
 AAAAnimation/AAAAnimation.vcxproj           |  2 ++
 AAAAnimation/AAAAnimation.vcxproj.filters   |  6 ++++++
 AAAAnimation/player/ascii_player_thread.cpp |  3 ++-
 AAAAnimation/utils.asm                      | 20 ++++++++++++++++++++
 AAAAnimation/utils.h                        |  3 +++
 5 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 AAAAnimation/utils.asm
 create mode 100644 AAAAnimation/utils.h

diff --git a/AAAAnimation/AAAAnimation.vcxproj b/AAAAnimation/AAAAnimation.vcxproj
index 677b4e0..0e5029a 100644
--- a/AAAAnimation/AAAAnimation.vcxproj
+++ b/AAAAnimation/AAAAnimation.vcxproj
@@ -119,6 +119,7 @@
     <ClCompile Include="main.cpp" />
   </ItemGroup>
   <ItemGroup>
+    <MASM Include="utils.asm" />
     <MASM Include="transform.asm">
       <FileType>Document</FileType>
     </MASM>
@@ -128,6 +129,7 @@
     <ClInclude Include="ffmpeg\stream_wrapper.h" />
     <ClInclude Include="ffmpeg\video_decoder.h" />
     <QtMoc Include="player\ascii_player_thread.h" />
+    <ClInclude Include="utils.h" />
     <ClInclude Include="transform.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
diff --git a/AAAAnimation/AAAAnimation.vcxproj.filters b/AAAAnimation/AAAAnimation.vcxproj.filters
index c4a6cbe..55e1102 100644
--- a/AAAAnimation/AAAAnimation.vcxproj.filters
+++ b/AAAAnimation/AAAAnimation.vcxproj.filters
@@ -57,11 +57,17 @@
     <ClInclude Include="transform.h">
       <Filter>Source Files</Filter>
     </ClInclude>
+    <ClInclude Include="utils.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <MASM Include="transform.asm">
       <Filter>Source Files</Filter>
     </MASM>
+    <MASM Include="utils.asm">
+      <Filter>Source Files</Filter>
+    </MASM>
   </ItemGroup>
   <ItemGroup>
     <QtMoc Include="player\ascii_player_thread.h">
diff --git a/AAAAnimation/player/ascii_player_thread.cpp b/AAAAnimation/player/ascii_player_thread.cpp
index d01ca5c..6754c51 100644
--- a/AAAAnimation/player/ascii_player_thread.cpp
+++ b/AAAAnimation/player/ascii_player_thread.cpp
@@ -3,6 +3,7 @@
 #include "../ffmpeg/video_decoder.h"
 #include "../console/console_controller.h"
 #include "../transform.h"
+#include "../utils.h"
 #include <QThread>
 
 AsciiPlayerThread::AsciiPlayerThread()
@@ -41,7 +42,7 @@ void AsciiPlayerThread::run()
 			transform(frame->data[0], arr, width, height, frame->linesize[0]);
 			// check time again
 			// wait until the proper time and play this frame
-			while (play_time - 150 > position); // 150ms offset to avoid drop too many frames
+			wait_until_smaller(play_time - 150, &position); // 150ms offset to avoid drop too many frames
 			std::cout << arr;
 			console_controller.top();
 		}
diff --git a/AAAAnimation/utils.asm b/AAAAnimation/utils.asm
new file mode 100644
index 0000000..9a1b7a2
--- /dev/null
+++ b/AAAAnimation/utils.asm
@@ -0,0 +1,20 @@
+wait_until_smaller PROTO
+; arguments
+; xmm0: REAL4 a REAL4 variable need to be compared
+; rdx: SQWORD PTR a SQWORD pointer which value be pointed would increase
+; this procedure would block the thread until the condition is fulfilled
+; Caution: it may cause the thread is blocked by a infinite loop
+.CODE
+wait_until_smaller PROC
+    push rbp
+    mov rbp, rsp
+compare:
+    cvtsi2ss xmm1, SQWORD PTR [rdx] ; convert rdx to REAL4 type and store it in xmm1 
+    comiss xmm0,xmm1 ; compare xmm0 with xmm1
+    jbe fufilled ; jump to fufilled if xmm0 <= xmm1
+    jmp compare ; jump to compare if xmm0 > xmm1
+fufilled:
+    leave
+    ret
+wait_until_smaller ENDP
+END
\ No newline at end of file
diff --git a/AAAAnimation/utils.h b/AAAAnimation/utils.h
new file mode 100644
index 0000000..9ffb53c
--- /dev/null
+++ b/AAAAnimation/utils.h
@@ -0,0 +1,3 @@
+#pragma once
+#include <QThread>
+extern "C" void wait_until_smaller(float, qint64*);
\ No newline at end of file