From 19cd46f7f835412f01c72282dc576c886e790b3f Mon Sep 17 00:00:00 2001
From: tseng0201 <99745983+tseng0201@users.noreply.github.com>
Date: Fri, 13 Jan 2023 04:32:28 +0800
Subject: [PATCH 1/3] IMPLEMENT COMBINE SCREENS AND CUT WIPE SCREEN EFFECT
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Reduce memory use for doom
Control flag "DISABLE_WIPES" and "COMBINE_SCREENS" are define in doomdef.h.
DISABLE_WIPES will cut wipe screen effect, COMBINE_SCREENS will discard screen buffer_1、buffer_2、buffer_3.
V_Init() function make four screen buffers pointer to same address(address of screen buffer #0) In v_video.c.
DOOMHEAP are replaced by static array and it size are controled by DOOM_HEAP_SIZE, both are in i_system.c.
Screen buffers are replaced by static array and I_AllocLow will return screen buffers directly in i_system.c.
If cut wipe screen effect, in f_wipe.c only wipe_StartScreen()、wipe_EndScreen()、wipe_ScreenWipe() will remain,
wipe_ScreenWipe() only copy data from screen buffer_3 to screen buffer_0 directly.
---
src/doomdef.h | 9 +++++++++
src/f_wipe.c | 19 ++++++++++++++++++-
src/riscv/i_system.c | 28 +++++++++++++++++++++++-----
src/v_video.c | 9 ++++++++-
4 files changed, 58 insertions(+), 7 deletions(-)
diff --git a/src/doomdef.h b/src/doomdef.h
index ebd51f0..404ce8e 100644
--- a/src/doomdef.h
+++ b/src/doomdef.h
@@ -27,6 +27,15 @@
#include <stdio.h>
#include <string.h>
+// Disable screens wipe effect, you will get worse game experience,
+// but it can save about 130KB on DOOMHEAP.
+#define DISABLE_WIPES
+
+// Discard screen buffers, any screen effect will direct output on your screen,
+// It can save 192kb on heap.
+// Remeber you can only use this when disable screens wipe.
+#define COMBINE_SCREENS
+
// The packed attribute forces structures to be packed into the minimum
// space necessary. If this is not done, the compiler may align structure
// fields differently to optimise memory access, inflating the overall
diff --git a/src/f_wipe.c b/src/f_wipe.c
index d46607b..cf20792 100644
--- a/src/f_wipe.c
+++ b/src/f_wipe.c
@@ -46,7 +46,7 @@ static byte* wipe_scr_start;
static byte* wipe_scr_end;
static byte* wipe_scr;
-
+#ifndef DISABLE_WIPES
void
wipe_shittyColMajorXform
( short* array,
@@ -233,6 +233,7 @@ wipe_exitMelt
Z_Free(y);
return 0;
}
+#endif
int
wipe_StartScreen
@@ -246,6 +247,7 @@ wipe_StartScreen
return 0;
}
+#ifndef DISABLE_WIPES
int
wipe_EndScreen
( int x,
@@ -301,3 +303,18 @@ wipe_ScreenWipe
return !go;
}
+#else
+int
+wipe_ScreenWipe
+( int wipeno,
+ int x,
+ int y,
+ int width,
+ int height,
+ int ticks )
+{
+ //Because we don't need wipe effct, just move screens[3] to screens[0]
+ memcpy( screens[0], wipe_scr_end, width*height );
+ return 1;
+}
+#endif
diff --git a/src/riscv/i_system.c b/src/riscv/i_system.c
index 2ed5c50..e9084e6 100644
--- a/src/riscv/i_system.c
+++ b/src/riscv/i_system.c
@@ -39,6 +39,21 @@
#include "console.h"
+#ifdef COMBINE_SCREENS
+unsigned char CombinedScreens[SCREENWIDTH*SCREENHEIGHT];
+#else
+unsigned char CombinedScreens[SCREENWIDTH*SCREENHEIGHT*4];
+#endif
+
+/* Original 6M - wipe function (130560 bytes) */
+#ifdef DISABLE_WIPES
+#define DOOM_HEAP_SIZE 6*1024*1024 - 130560
+#else
+#define DOOM_HEAP_SIZE 6*1024*1024
+#endif
+
+unsigned char DOOMHeap[DOOM_HEAP_SIZE];
+
enum {
KEY_EVENT = 0,
MOUSE_MOTION_EVENT = 1,
@@ -139,9 +154,9 @@ I_Init(void)
byte *
I_ZoneBase(int *size)
{
- /* Give 6M to DOOM */
- *size = 6 * 1024 * 1024;
- return (byte *) malloc (*size);
+ /* Give DOOM_HEAP_SIZE to DOOM */
+ *size = DOOM_HEAP_SIZE;
+ return (byte *) DOOMHeap;
}
@@ -313,8 +328,11 @@ I_Quit(void)
byte *
I_AllocLow(int length)
{
- /* FIXME: check if memory allocation succeeds */
- return calloc(1, length);
+ /* Return screen buffer */
+ byte* mem;
+ mem = CombinedScreens;
+ memset (mem,0,length);
+ return mem;
}
diff --git a/src/v_video.c b/src/v_video.c
index 881f4ab..301b835 100644
--- a/src/v_video.c
+++ b/src/v_video.c
@@ -463,9 +463,16 @@ void V_Init (void)
byte* base;
// stick these in low dos memory on PCs
-
+
+#ifndef COMBINE_SCREENS
base = I_AllocLow (SCREENWIDTH*SCREENHEIGHT*4);
for (i=0 ; i<4 ; i++)
screens[i] = base + i*SCREENWIDTH*SCREENHEIGHT;
+#else
+ base = I_AllocLow (SCREENWIDTH*SCREENHEIGHT);
+
+ for (i=0 ; i<4 ; i++)
+ screens[i] = base;
+#endif
}
From 3f47238667a91cac7263c8d69065025f6a2cacd2 Mon Sep 17 00:00:00 2001
From: tseng0201 <99745983+tseng0201@users.noreply.github.com>
Date: Sat, 14 Jan 2023 00:01:11 +0900
Subject: [PATCH 2/3] PROVIDE THE PROOF FOR MEMORY REDUCION
provide the proof for memory reduction, detail in doomdef.h
---
src/doomdef.h | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/src/doomdef.h b/src/doomdef.h
index 404ce8e..ef545ad 100644
--- a/src/doomdef.h
+++ b/src/doomdef.h
@@ -29,10 +29,19 @@
// Disable screens wipe effect, you will get worse game experience,
// but it can save about 130KB on DOOMHEAP.
+// In f_wipe.c, only wipe_initMelt() and wipe_shittyColMajorXform() call Z_Malloc ask for some sapce,
+// wipe_initMelt() ask 320 * 8(width * sizeof(int)) = 2560 bytes,
+// wipe_shittyColMajorXform() ask 160 * 200 * 2(width/2 * height*2) = 64000 bytes,
+// it will be call twice so it will totaly ask 128000 bytes,
+// it means we can save 2560 + 128000 = 130560 bytes on DOOMHEAP when disable screens wipe.
#define DISABLE_WIPES
// Discard screen buffers, any screen effect will direct output on your screen,
-// It can save 192kb on heap.
+// It can save 192kb memory usage.
+// Each screen buffer is 320 * 200 * 1 = 64000 bytes,
+// COMBINE_SCREENS will make four screen buffers merge to one,
+// so we can save (4 - 1) * 320 * 200 = 192000 bytes.
+// In this Implement it will set "CombinedScreens[SCREENWIDTH*SCREENHEIGHT]" to replace original "CombinedScreens[SCREENWIDTH*SCREENHEIGHT*4]".
// Remeber you can only use this when disable screens wipe.
#define COMBINE_SCREENS
From 39c9238cac9a44d46b611f09cdbab876d6832e9e Mon Sep 17 00:00:00 2001
From: tseng0201 <99745983+tseng0201@users.noreply.github.com>
Date: Sat, 14 Jan 2023 01:43:47 +0900
Subject: [PATCH 3/3] ADD STATIC MODIFIER FOR HELP COMPILER OPTIMIZATION
Add static modifier on CombinedScreens and DOOMHeap in i_system.c for help compiler optimization.
No other file use both array directly and they use them by pointer.
---
src/riscv/i_system.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/src/riscv/i_system.c b/src/riscv/i_system.c
index e9084e6..b08cfcc 100644
--- a/src/riscv/i_system.c
+++ b/src/riscv/i_system.c
@@ -40,9 +40,9 @@
#include "console.h"
#ifdef COMBINE_SCREENS
-unsigned char CombinedScreens[SCREENWIDTH*SCREENHEIGHT];
+static unsigned char CombinedScreens[SCREENWIDTH*SCREENHEIGHT];
#else
-unsigned char CombinedScreens[SCREENWIDTH*SCREENHEIGHT*4];
+static unsigned char CombinedScreens[SCREENWIDTH*SCREENHEIGHT*4];
#endif
/* Original 6M - wipe function (130560 bytes) */
@@ -52,7 +52,7 @@ unsigned char CombinedScreens[SCREENWIDTH*SCREENHEIGHT*4];
#define DOOM_HEAP_SIZE 6*1024*1024
#endif
-unsigned char DOOMHeap[DOOM_HEAP_SIZE];
+static unsigned char DOOMHeap[DOOM_HEAP_SIZE];
enum {
KEY_EVENT = 0,