pflib.c

   1 /*
   2  * PixelFormat conversion library.
   3  *
   4  * Author: Gerd Hoffmann <kraxel@redhat.com>
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2.  See
   7  * the COPYING file in the top-level directory.
   8  *
   9  */
  10 #include "qemu-common.h"
  11 #include "console.h"
  12 #include "pflib.h"
  13
  14 typedef struct QemuPixel QemuPixel;
  15
  16 typedef void (*pf_convert)(QemuPfConv *conv,
  17                            void *dst, void *src, uint32_t cnt);
  18 typedef void (*pf_convert_from)(PixelFormat *pf,
  19                                 QemuPixel *dst, void *src, uint32_t cnt);
  20 typedef void (*pf_convert_to)(PixelFormat *pf,
  21                               void *dst, QemuPixel *src, uint32_t cnt);
  22
  23 struct QemuPfConv {
  24     pf_convert        convert;
  25     PixelFormat       src;
  26     PixelFormat       dst;
  27
  28     /* for copy_generic() */
  29     pf_convert_from   conv_from;
  30     pf_convert_to     conv_to;
  31     QemuPixel         *conv_buf;
  32     uint32_t          conv_cnt;
  33 };
  34
  35 struct QemuPixel {
  36     uint8_t red;
  37     uint8_t green;
  38     uint8_t blue;
  39     uint8_t alpha;
  40 };
  41
  42 /* ----------------------------------------------------------------------- */
  43 /* PixelFormat -> QemuPixel conversions                                    */
  44
  45 static void conv_16_to_pixel(PixelFormat *pf,
  46                              QemuPixel *dst, void *src, uint32_t cnt)
  47 {
  48     uint16_t *src16 = src;
  49
  50     while (cnt > 0) {
  51         dst->red   = ((*src16 & pf->rmask) >> pf->rshift) << (8 - pf->rbits);
  52         dst->green = ((*src16 & pf->gmask) >> pf->gshift) << (8 - pf->gbits);
  53         dst->blue  = ((*src16 & pf->bmask) >> pf->bshift) << (8 - pf->bbits);
  54         dst->alpha = ((*src16 & pf->amask) >> pf->ashift) << (8 - pf->abits);
  55         dst++, src16++, cnt--;
  56     }
  57 }
  58
  59 /* assumes pf->{r,g,b,a}bits == 8 */
  60 static void conv_32_to_pixel_fast(PixelFormat *pf,
  61                                   QemuPixel *dst, void *src, uint32_t cnt)
  62 {
  63     uint32_t *src32 = src;
  64
  65     while (cnt > 0) {
  66         dst->red   = (*src32 & pf->rmask) >> pf->rshift;
  67         dst->green = (*src32 & pf->gmask) >> pf->gshift;
  68         dst->blue  = (*src32 & pf->bmask) >> pf->bshift;
  69         dst->alpha = (*src32 & pf->amask) >> pf->ashift;
  70         dst++, src32++, cnt--;
  71     }
  72 }
  73
  74 static void conv_32_to_pixel_generic(PixelFormat *pf,
  75                                      QemuPixel *dst, void *src, uint32_t cnt)
  76 {
  77     uint32_t *src32 = src;
  78
  79     while (cnt > 0) {
  80         if (pf->rbits < 8) {
  81             dst->red   = ((*src32 & pf->rmask) >> pf->rshift) << (8 - pf->rbits);
  82         } else {
  83             dst->red   = ((*src32 & pf->rmask) >> pf->rshift) >> (pf->rbits - 8);
  84         }
  85         if (pf->gbits < 8) {
  86             dst->green = ((*src32 & pf->gmask) >> pf->gshift) << (8 - pf->gbits);
  87         } else {
  88             dst->green = ((*src32 & pf->gmask) >> pf->gshift) >> (pf->gbits - 8);
  89         }
  90         if (pf->bbits < 8) {
  91             dst->blue  = ((*src32 & pf->bmask) >> pf->bshift) << (8 - pf->bbits);
  92         } else {
  93             dst->blue  = ((*src32 & pf->bmask) >> pf->bshift) >> (pf->bbits - 8);
  94         }
  95         if (pf->abits < 8) {
  96             dst->alpha = ((*src32 & pf->amask) >> pf->ashift) << (8 - pf->abits);
  97         } else {
  98             dst->alpha = ((*src32 & pf->amask) >> pf->ashift) >> (pf->abits - 8);
  99         }
 100         dst++, src32++, cnt--;
 101     }
 102 }
 103
 104 /* ----------------------------------------------------------------------- */
 105 /* QemuPixel -> PixelFormat conversions                                    */
 106
 107 static void conv_pixel_to_16(PixelFormat *pf,
 108                              void *dst, QemuPixel *src, uint32_t cnt)
 109 {
 110     uint16_t *dst16 = dst;
 111
 112     while (cnt > 0) {
 113         *dst16  = ((uint16_t)src->red   >> (8 - pf->rbits)) << pf->rshift;
 114         *dst16 |= ((uint16_t)src->green >> (8 - pf->gbits)) << pf->gshift;
 115         *dst16 |= ((uint16_t)src->blue  >> (8 - pf->bbits)) << pf->bshift;
 116         *dst16 |= ((uint16_t)src->alpha >> (8 - pf->abits)) << pf->ashift;
 117         dst16++, src++, cnt--;
 118     }
 119 }
 120
 121 static void conv_pixel_to_32(PixelFormat *pf,
 122                              void *dst, QemuPixel *src, uint32_t cnt)
 123 {
 124     uint32_t *dst32 = dst;
 125
 126     while (cnt > 0) {
 127         *dst32  = ((uint32_t)src->red   >> (8 - pf->rbits)) << pf->rshift;
 128         *dst32 |= ((uint32_t)src->green >> (8 - pf->gbits)) << pf->gshift;
 129         *dst32 |= ((uint32_t)src->blue  >> (8 - pf->bbits)) << pf->bshift;
 130         *dst32 |= ((uint32_t)src->alpha >> (8 - pf->abits)) << pf->ashift;
 131         dst32++, src++, cnt--;
 132     }
 133 }
 134
 135 /* ----------------------------------------------------------------------- */
 136 /* PixelFormat -> PixelFormat conversions                                  */
 137
 138 static void convert_copy(QemuPfConv *conv, void *dst, void *src, uint32_t cnt)
 139 {
 140     uint32_t bytes = cnt * conv->src.bytes_per_pixel;
 141     memcpy(dst, src, bytes);
 142 }
 143
 144 static void convert_generic(QemuPfConv *conv, void *dst, void *src, uint32_t cnt)
 145 {
 146     if (conv->conv_cnt < cnt) {
 147         conv->conv_cnt = cnt;
 148         conv->conv_buf = qemu_realloc(conv->conv_buf, sizeof(QemuPixel) * conv->conv_cnt);
 149     }
 150     conv->conv_from(&conv->src, conv->conv_buf, src, cnt);
 151     conv->conv_to(&conv->dst, dst, conv->conv_buf, cnt);
 152 }
 153
 154 /* ----------------------------------------------------------------------- */
 155 /* public interface                                                        */
 156
 157 QemuPfConv *qemu_pf_conv_get(PixelFormat *dst, PixelFormat *src)
 158 {
 159     QemuPfConv *conv = qemu_mallocz(sizeof(QemuPfConv));
 160
 161     conv->src = *src;
 162     conv->dst = *dst;
 163
 164     if (memcmp(&conv->src, &conv->dst, sizeof(PixelFormat)) == 0) {
 165         /* formats identical, can simply copy */
 166         conv->convert = convert_copy;
 167     } else {
 168         /* generic two-step conversion: src -> QemuPixel -> dst  */
 169         switch (conv->src.bytes_per_pixel) {
 170         case 2:
 171             conv->conv_from = conv_16_to_pixel;
 172             break;
 173         case 4:
 174             if (conv->src.rbits == 8 && conv->src.gbits == 8 && conv->src.bbits == 8) {
 175                 conv->conv_from = conv_32_to_pixel_fast;
 176             } else {
 177                 conv->conv_from = conv_32_to_pixel_generic;
 178             }
 179             break;
 180         default:
 181             goto err;
 182         }
 183         switch (conv->dst.bytes_per_pixel) {
 184         case 2:
 185             conv->conv_to = conv_pixel_to_16;
 186             break;
 187         case 4:
 188             conv->conv_to = conv_pixel_to_32;
 189             break;
 190         default:
 191             goto err;
 192         }
 193         conv->convert = convert_generic;
 194     }
 195     return conv;
 196
 197 err:
 198     qemu_free(conv);
 199     return NULL;
 200 }
 201
 202 void qemu_pf_conv_run(QemuPfConv *conv, void *dst, void *src, uint32_t cnt)
 203 {
 204     conv->convert(conv, dst, src, cnt);
 205 }
 206
 207 void qemu_pf_conv_put(QemuPfConv *conv)
 208 {
 209     if (conv) {
 210         qemu_free(conv->conv_buf);
 211         qemu_free(conv);
 212     }
 213 }