gfx_put_alpha.c

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/* ALPHA drawing method for PUT statement */

#include "fb_gfx.h"


extern void fb_hPutPSetC(unsigned char *src, unsigned char *dest, int w, int h, int src_pitch, int dest_pitch, int alpha, BLENDER *blender, void *param);

#ifdef HOST_X86

#include "x86/fb_gfx_mmx.h"

extern void fb_hPutPSetMMX(unsigned char *src, unsigned char *dest, int w, int h, int src_pitch, int dest_pitch, int alpha, BLENDER *blender, void *param);
extern void fb_hPutAlpha4MMX(unsigned char *src, unsigned char *dest, int w, int h, int src_pitch, int dest_pitch, int alpha, BLENDER *blender, void *param);

#endif


/*:::::*/
static void fb_hPutAlpha4C(unsigned char *src, unsigned char *dest, int w, int h, int src_pitch, int dest_pitch, int alpha, BLENDER *blender, void *param)
{
        unsigned int *s = (unsigned int *)src;
        unsigned int *d, sc, dc, a, drb, dga, srb, sga;
        int x;
        
        src_pitch = (src_pitch >> 2) - w;
        for (; h; h--) {
                d = (unsigned int *)dest;
                for (x = w; x; x--) {
                        sc = *s++;
                        dc = *d;
                        a = (sc >> 24);
                        srb = sc & MASK_RB_32;
                        sga = sc & MASK_GA_32;
                        drb = dc & MASK_RB_32;
                        dga = dc & MASK_GA_32;
                        srb = ((srb - drb) * a) >> 8;
                        sga = ((sga - dga) >> 8) * a;
                        *d++ = ((drb + srb) & MASK_RB_32) | ((dga + sga) & MASK_GA_32);
                }
                s += src_pitch;
                dest += dest_pitch;
        }
}


/*:::::*/
void fb_hPutAlpha(unsigned char *src, unsigned char *dest, int w, int h, int src_pitch, int dest_pitch, int alpha, BLENDER *blender, void *param)
{
        static PUTTER *all_putters[] = {
                fb_hPutPSetC, fb_hPutPSetC, NULL, fb_hPutAlpha4C,
#ifdef HOST_X86
                fb_hPutPSetMMX, fb_hPutPSetMMX, NULL, fb_hPutAlpha4MMX,
#endif
        };
        PUTTER *putter;
        FB_GFXCTX *context = fb_hGetContext();
        
        if (!context->putter[PUT_MODE_ALPHA]) {
#ifdef HOST_X86
                if (__fb_gfx->flags & HAS_MMX)
                        context->putter[PUT_MODE_ALPHA] = &all_putters[4];
                else
#endif
                        context->putter[PUT_MODE_ALPHA] = &all_putters[0];
        }
        putter = context->putter[PUT_MODE_ALPHA][context->target_bpp - 1];
        
        putter(src, dest, w, h, src_pitch, dest_pitch, alpha, blender, param);
}