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Date: Mon, 17 Nov 2003 21:59:24 -0800 From: Pete Shinners Subject: [SDL] directfb cursor patch here is a quick and dirty patch that allows directfb to change the visibility of the cursor. this display backend still has no way to change the actual cursor shape, but being able to set the cursor visibility is a simple change that should offer some benefits. the code was largely based on the cursor code for other sdl backends. and this documentation. http://directfb.org/documentation/DirectFB_Reference/IDirectFBDisplayLayer_SetCursorOpacity.html
author Sam Lantinga <slouken@libsdl.org>
date Sun, 04 Jan 2004 15:57:16 +0000
parents a9e38f3b8e4d
children b4b64bb88f2f
line wrap: on
line source

// MMX assembler version of SDL_MixAudio for signed little endian 16 bit samples and signed 8 bit samples
// Copyright 2002 Stephane Marchesin (stephane.marchesin@wanadoo.fr)
// This code is licensed under the LGPL (see COPYING for details)
// 
// Assumes buffer size in bytes is a multiple of 16
// Assumes SDL_MIX_MAXVOLUME = 128


////////////////////////////////////////////////
// Mixing for 16 bit signed buffers
////////////////////////////////////////////////

#if defined(i386) && defined(__GNUC__) && defined(USE_ASMBLIT)
void SDL_MixAudio_MMX_S16(char* dst,char* src,unsigned int size,int volume)
{
    __asm__ __volatile__ (

"	movl %0,%%edi\n"	// edi = dst
"	movl %1,%%esi\n"	// esi = src
"	movl %3,%%eax\n"	// eax = volume

"	movl %2,%%ebx\n"	// ebx = size

"	shrl $4,%%ebx\n"	// process 16 bytes per iteration = 8 samples

"	jz .endS16\n"

"	pxor %%mm0,%%mm0\n"

"	movd %%eax,%%mm0\n"
"	movq %%mm0,%%mm1\n"
"	psllq $16,%%mm0\n"
"	por %%mm1,%%mm0\n"
"	psllq $16,%%mm0\n"
"	por %%mm1,%%mm0\n"
"	psllq $16,%%mm0\n"
"	por %%mm1,%%mm0\n"		// mm0 = vol|vol|vol|vol

".align 16\n"
"	.mixloopS16:\n"

"	movq (%%esi),%%mm1\n" // mm1 = a|b|c|d

"	movq %%mm1,%%mm2\n" // mm2 = a|b|c|d

"	movq 8(%%esi),%%mm4\n" // mm4 = e|f|g|h

	// pré charger le buffer dst dans mm7
"	movq (%%edi),%%mm7\n" // mm7 = dst[0]"

	// multiplier par le volume
"	pmullw %%mm0,%%mm1\n" // mm1 = l(a*v)|l(b*v)|l(c*v)|l(d*v)

"	pmulhw %%mm0,%%mm2\n" // mm2 = h(a*v)|h(b*v)|h(c*v)|h(d*v)
"	movq %%mm4,%%mm5\n" // mm5 = e|f|g|h

"	pmullw %%mm0,%%mm4\n" // mm4 = l(e*v)|l(f*v)|l(g*v)|l(h*v)

"	pmulhw %%mm0,%%mm5\n" // mm5 = h(e*v)|h(f*v)|h(g*v)|h(h*v)
"	movq %%mm1,%%mm3\n" // mm3 = l(a*v)|l(b*v)|l(c*v)|l(d*v)

"	punpckhwd %%mm2,%%mm1\n" // mm1 = a*v|b*v

"	movq %%mm4,%%mm6\n" // mm6 = l(e*v)|l(f*v)|l(g*v)|l(h*v)
"	punpcklwd %%mm2,%%mm3\n" // mm3 = c*v|d*v

"	punpckhwd %%mm5,%%mm4\n" // mm4 = e*f|f*v

"	punpcklwd %%mm5,%%mm6\n" // mm6 = g*v|h*v

	// pré charger le buffer dst dans mm5
"	movq 8(%%edi),%%mm5\n" // mm5 = dst[1]

	// diviser par 128
"	psrad $7,%%mm1\n" // mm1 = a*v/128|b*v/128 , 128 = SDL_MIX_MAXVOLUME
"	addl $16,%%esi\n"

"	psrad $7,%%mm3\n" // mm3 = c*v/128|d*v/128

"	psrad $7,%%mm4\n" // mm4 = e*v/128|f*v/128

	// mm1 = le sample avec le volume modifié
"	packssdw %%mm1,%%mm3\n" // mm3 = s(a*v|b*v|c*v|d*v)

"	psrad $7,%%mm6\n" // mm6= g*v/128|h*v/128
"	paddsw %%mm7,%%mm3\n" // mm3 = adjust_volume(src)+dst

	// mm4 = le sample avec le volume modifié
"	packssdw %%mm4,%%mm6\n" // mm6 = s(e*v|f*v|g*v|h*v)
"	movq %%mm3,(%%edi)\n"

"	paddsw %%mm5,%%mm6\n" // mm6 = adjust_volume(src)+dst

"	movq %%mm6,8(%%edi)\n"

"	addl $16,%%edi\n"

"	dec %%ebx\n"

"	jnz .mixloopS16\n"

"	emms\n"

".endS16:\n"
	 :
	 : "m" (dst), "m"(src),"m"(size),
	 "m"(volume)
	 : "eax","ebx", "esi", "edi","memory"
	 );
}



////////////////////////////////////////////////
// Mixing for 8 bit signed buffers
////////////////////////////////////////////////

void SDL_MixAudio_MMX_S8(char* dst,char* src,unsigned int size,int volume)
{
    __asm__ __volatile__ (

"	movl %0,%%edi\n"	// edi = dst
"	movl %1,%%esi\n"	// esi = src
"	movl %3,%%eax\n"	// eax = volume

"	movd %%ebx,%%mm0\n"
"	movq %%mm0,%%mm1\n"
"	psllq $16,%%mm0\n"
"	por %%mm1,%%mm0\n"
"	psllq $16,%%mm0\n"
"	por %%mm1,%%mm0\n"
"	psllq $16,%%mm0\n"
"	por %%mm1,%%mm0\n"

"	movl %2,%%ebx\n"	// ebx = size
"	shr $3,%%ebx\n"	// process 8 bytes per iteration = 8 samples

"	cmp $0,%%ebx\n"
"	je .endS8\n"

".align 16\n"
"	.mixloopS8:\n"

"	pxor %%mm2,%%mm2\n"		// mm2 = 0
"	movq (%%esi),%%mm1\n"	// mm1 = a|b|c|d|e|f|g|h

"	movq %%mm1,%%mm3\n" 	// mm3 = a|b|c|d|e|f|g|h

	// on va faire le "sign extension" en faisant un cmp avec 0 qui retourne 1 si <0, 0 si >0
"	pcmpgtb %%mm1,%%mm2\n"	// mm2 = 11111111|00000000|00000000....

"	punpckhbw %%mm2,%%mm1\n"	// mm1 = 0|a|0|b|0|c|0|d

"	punpcklbw %%mm2,%%mm3\n"	// mm3 = 0|e|0|f|0|g|0|h
"	movq (%%edi),%%mm2\n"	// mm2 = destination

"	pmullw %%mm0,%%mm1\n"	// mm1 = v*a|v*b|v*c|v*d
"	addl $8,%%esi\n"

"	pmullw %%mm0,%%mm3\n"	// mm3 = v*e|v*f|v*g|v*h
"	psraw $7,%%mm1\n"		// mm1 = v*a/128|v*b/128|v*c/128|v*d/128 

"	psraw $7,%%mm3\n"		// mm3 = v*e/128|v*f/128|v*g/128|v*h/128

"	packsswb %%mm1,%%mm3\n"	// mm1 = v*a/128|v*b/128|v*c/128|v*d/128|v*e/128|v*f/128|v*g/128|v*h/128

"	paddsb %%mm2,%%mm3\n"	// add to destination buffer

"	movq %%mm3,(%%edi)\n"	// store back to ram
"	addl $8,%%edi\n"

"	dec %%ebx\n"

"	jnz .mixloopS8\n"

".endS8:\n"
"	emms\n"
	 :
	 : "m" (dst), "m"(src),"m"(size),
	 "m"(volume)
	 : "eax","ebx", "esi", "edi","memory"
	 );
}
#endif