/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

#include "SDL_blit.h"

/* This code assumes that r, g, b, a are the source color,

 * and in the blend and add case, the RGB values are premultiplied by a.

 */

#define DRAW_MUL(_a, _b) (((unsigned)(_a)*(_b))/255)

#define DRAW_FASTSETPIXEL(type) \

    *pixel = (type) color

#define DRAW_FASTSETPIXEL1 DRAW_FASTSETPIXEL(Uint8)

#define DRAW_FASTSETPIXEL2 DRAW_FASTSETPIXEL(Uint16)

#define DRAW_FASTSETPIXEL4 DRAW_FASTSETPIXEL(Uint32)

#define DRAW_FASTSETPIXELXY(x, y, type, bpp, color) \

    *(type *)((Uint8 *)dst->pixels + (y) * dst->pitch \

                                   + (x) * bpp) = (type) color

#define DRAW_FASTSETPIXELXY1(x, y) DRAW_FASTSETPIXELXY(x, y, Uint8, 1, color)

#define DRAW_FASTSETPIXELXY2(x, y) DRAW_FASTSETPIXELXY(x, y, Uint16, 2, color)

#define DRAW_FASTSETPIXELXY4(x, y) DRAW_FASTSETPIXELXY(x, y, Uint32, 4, color)

#define DRAW_SETPIXEL(setpixel) \

do { \

    unsigned sr = r, sg = g, sb = b, sa = a; \

    setpixel; \

} while (0)

#define DRAW_SETPIXEL_BLEND(getpixel, setpixel) \

do { \

    unsigned sr, sg, sb, sa; sa; \

    getpixel; \

    sr = DRAW_MUL(inva, sr) + r; \

    sg = DRAW_MUL(inva, sg) + g; \

    sb = DRAW_MUL(inva, sb) + b; \

    setpixel; \

} while (0)

#define DRAW_SETPIXEL_ADD(getpixel, setpixel) \

do { \

    unsigned sr, sg, sb, sa; sa; \

    getpixel; \

    sr += r; if (sr > 0xff) sr = 0xff; \

    sg += g; if (sg > 0xff) sg = 0xff; \

    sb += b; if (sb > 0xff) sb = 0xff; \

    setpixel; \

} while (0)

#define DRAW_SETPIXEL_MOD(getpixel, setpixel) \

do { \

    unsigned sr, sg, sb, sa; sa; \

    getpixel; \

    sr = DRAW_MUL(sr, r); \

    sg = DRAW_MUL(sg, g); \

    sb = DRAW_MUL(sb, b); \

    setpixel; \

} while (0)

#define DRAW_SETPIXELXY(x, y, type, bpp, op) \

do { \

    type *pixel = (type *)((Uint8 *)dst->pixels + (y) * dst->pitch \

                                                + (x) * bpp); \

    op; \

} while (0)

/*

 * Define draw operators for RGB555

 */

#define DRAW_SETPIXEL_RGB555 \

    DRAW_SETPIXEL(RGB555_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXEL_BLEND_RGB555 \

    DRAW_SETPIXEL_BLEND(RGB_FROM_RGB555(*pixel, sr, sg, sb), \

                        RGB555_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXEL_ADD_RGB555 \

    DRAW_SETPIXEL_ADD(RGB_FROM_RGB555(*pixel, sr, sg, sb), \

                      RGB555_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXEL_MOD_RGB555 \

    DRAW_SETPIXEL_MOD(RGB_FROM_RGB555(*pixel, sr, sg, sb), \

                      RGB555_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXELXY_RGB555(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_RGB555)

#define DRAW_SETPIXELXY_BLEND_RGB555(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_BLEND_RGB555)

#define DRAW_SETPIXELXY_ADD_RGB555(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_ADD_RGB555)

#define DRAW_SETPIXELXY_MOD_RGB555(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_MOD_RGB555)

/*

 * Define draw operators for RGB565

 */

#define DRAW_SETPIXEL_RGB565 \

    DRAW_SETPIXEL(RGB565_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXEL_BLEND_RGB565 \

    DRAW_SETPIXEL_BLEND(RGB_FROM_RGB565(*pixel, sr, sg, sb), \

                        RGB565_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXEL_ADD_RGB565 \

    DRAW_SETPIXEL_ADD(RGB_FROM_RGB565(*pixel, sr, sg, sb), \

                      RGB565_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXEL_MOD_RGB565 \

    DRAW_SETPIXEL_MOD(RGB_FROM_RGB565(*pixel, sr, sg, sb), \

                      RGB565_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXELXY_RGB565(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_RGB565)

#define DRAW_SETPIXELXY_BLEND_RGB565(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_BLEND_RGB565)

#define DRAW_SETPIXELXY_ADD_RGB565(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_ADD_RGB565)

#define DRAW_SETPIXELXY_MOD_RGB565(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_MOD_RGB565)

/*

 * Define draw operators for RGB888

 */

#define DRAW_SETPIXEL_RGB888 \

    DRAW_SETPIXEL(RGB888_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXEL_BLEND_RGB888 \

    DRAW_SETPIXEL_BLEND(RGB_FROM_RGB888(*pixel, sr, sg, sb), \

                        RGB888_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXEL_ADD_RGB888 \

    DRAW_SETPIXEL_ADD(RGB_FROM_RGB888(*pixel, sr, sg, sb), \

                      RGB888_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXEL_MOD_RGB888 \

    DRAW_SETPIXEL_MOD(RGB_FROM_RGB888(*pixel, sr, sg, sb), \

                      RGB888_FROM_RGB(*pixel, sr, sg, sb))

#define DRAW_SETPIXELXY_RGB888(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_RGB888)

#define DRAW_SETPIXELXY_BLEND_RGB888(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_BLEND_RGB888)

#define DRAW_SETPIXELXY_ADD_RGB888(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_ADD_RGB888)

#define DRAW_SETPIXELXY_MOD_RGB888(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_MOD_RGB888)

/*

 * Define draw operators for ARGB8888

 */

#define DRAW_SETPIXEL_ARGB8888 \

    DRAW_SETPIXEL(ARGB8888_FROM_RGBA(*pixel, sr, sg, sb, sa))

#define DRAW_SETPIXEL_BLEND_ARGB8888 \

    DRAW_SETPIXEL_BLEND(RGBA_FROM_ARGB8888(*pixel, sr, sg, sb, sa), \

                        ARGB8888_FROM_RGBA(*pixel, sr, sg, sb, sa))

#define DRAW_SETPIXEL_ADD_ARGB8888 \

    DRAW_SETPIXEL_ADD(RGBA_FROM_ARGB8888(*pixel, sr, sg, sb, sa), \

                      ARGB8888_FROM_RGBA(*pixel, sr, sg, sb, sa))

#define DRAW_SETPIXEL_MOD_ARGB8888 \

    DRAW_SETPIXEL_MOD(RGBA_FROM_ARGB8888(*pixel, sr, sg, sb, sa), \

                      ARGB8888_FROM_RGBA(*pixel, sr, sg, sb, sa))

#define DRAW_SETPIXELXY_ARGB8888(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_ARGB8888)

#define DRAW_SETPIXELXY_BLEND_ARGB8888(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_BLEND_ARGB8888)

#define DRAW_SETPIXELXY_ADD_ARGB8888(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_ADD_ARGB8888)

#define DRAW_SETPIXELXY_MOD_ARGB8888(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_MOD_ARGB8888)

/*

 * Define draw operators for general RGB

 */

#define DRAW_SETPIXEL_RGB \

    DRAW_SETPIXEL(PIXEL_FROM_RGB(*pixel, fmt, sr, sg, sb))

#define DRAW_SETPIXEL_BLEND_RGB \

    DRAW_SETPIXEL_BLEND(RGB_FROM_PIXEL(*pixel, fmt, sr, sg, sb), \

                        PIXEL_FROM_RGB(*pixel, fmt, sr, sg, sb))

#define DRAW_SETPIXEL_ADD_RGB \

    DRAW_SETPIXEL_ADD(RGB_FROM_PIXEL(*pixel, fmt, sr, sg, sb), \

                      PIXEL_FROM_RGB(*pixel, fmt, sr, sg, sb))

#define DRAW_SETPIXEL_MOD_RGB \

    DRAW_SETPIXEL_MOD(RGB_FROM_PIXEL(*pixel, fmt, sr, sg, sb), \

                      PIXEL_FROM_RGB(*pixel, fmt, sr, sg, sb))

#define DRAW_SETPIXELXY2_RGB(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_RGB)

#define DRAW_SETPIXELXY4_RGB(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_RGB)

#define DRAW_SETPIXELXY2_BLEND_RGB(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_BLEND_RGB)

#define DRAW_SETPIXELXY4_BLEND_RGB(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_BLEND_RGB)

#define DRAW_SETPIXELXY2_ADD_RGB(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_ADD_RGB)

#define DRAW_SETPIXELXY4_ADD_RGB(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_ADD_RGB)

#define DRAW_SETPIXELXY2_MOD_RGB(x, y) \

    DRAW_SETPIXELXY(x, y, Uint16, 2, DRAW_SETPIXEL_MOD_RGB)

#define DRAW_SETPIXELXY4_MOD_RGB(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_MOD_RGB)

/*

 * Define draw operators for general RGBA

 */

#define DRAW_SETPIXEL_RGBA \

    DRAW_SETPIXEL(PIXEL_FROM_RGBA(*pixel, fmt, sr, sg, sb, sa))

#define DRAW_SETPIXEL_BLEND_RGBA \

    DRAW_SETPIXEL_BLEND(RGBA_FROM_PIXEL(*pixel, fmt, sr, sg, sb, sa), \

                        PIXEL_FROM_RGBA(*pixel, fmt, sr, sg, sb, sa))

#define DRAW_SETPIXEL_ADD_RGBA \

    DRAW_SETPIXEL_ADD(RGBA_FROM_PIXEL(*pixel, fmt, sr, sg, sb, sa), \

                      PIXEL_FROM_RGBA(*pixel, fmt, sr, sg, sb, sa))

#define DRAW_SETPIXEL_MOD_RGBA \

    DRAW_SETPIXEL_MOD(RGBA_FROM_PIXEL(*pixel, fmt, sr, sg, sb, sa), \

                      PIXEL_FROM_RGBA(*pixel, fmt, sr, sg, sb, sa))

#define DRAW_SETPIXELXY4_RGBA(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_RGBA)

#define DRAW_SETPIXELXY4_BLEND_RGBA(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_BLEND_RGBA)

#define DRAW_SETPIXELXY4_ADD_RGBA(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_ADD_RGBA)

#define DRAW_SETPIXELXY4_MOD_RGBA(x, y) \

    DRAW_SETPIXELXY(x, y, Uint32, 4, DRAW_SETPIXEL_MOD_RGBA)

/*

 * Define line drawing macro

 */

#define ABS(_x) ((_x) < 0 ? -(_x) : (_x))

/* Horizontal line */

#define HLINE(type, op, draw_end) \

{ \

    int length; \

    int pitch = (dst->pitch / dst->format->BytesPerPixel); \

    type *pixel; \

    if (x1 <= x2) { \

        pixel = (type *)dst->pixels + y1 * pitch + x1; \

        length = draw_end ? (x2-x1+1) : (x2-x1); \

    } else { \

        pixel = (type *)dst->pixels + y1 * pitch + x2; \

        if (!draw_end) { \

            ++pixel; \

        } \

        length = draw_end ? (x1-x2+1) : (x1-x2); \

    } \

    while (length--) { \

        op; \

        ++pixel; \

    } \

}

/* Vertical line */

#define VLINE(type, op, draw_end) \

{ \

    int length; \

    int pitch = (dst->pitch / dst->format->BytesPerPixel); \

    type *pixel; \

    if (y1 <= y2) { \

        pixel = (type *)dst->pixels + y1 * pitch + x1; \

        length = draw_end ? (y2-y1+1) : (y2-y1); \

    } else { \

        pixel = (type *)dst->pixels + y2 * pitch + x1; \

        if (!draw_end) { \

            pixel += pitch; \

        } \

        length = draw_end ? (y1-y2+1) : (y1-y2); \

    } \

    while (length--) { \

        op; \

        pixel += pitch; \

    } \

}

/* Diagonal line */

#define DLINE(type, op, draw_end) \

{ \

    int length; \

    int pitch = (dst->pitch / dst->format->BytesPerPixel); \

    type *pixel; \

    if (y1 <= y2) { \

        pixel = (type *)dst->pixels + y1 * pitch + x1; \

        if (x1 <= x2) { \

            ++pitch; \

        } else { \

            --pitch; \

        } \

        length = (y2-y1); \

    } else { \

        pixel = (type *)dst->pixels + y2 * pitch + x2; \

        if (x2 <= x1) { \

            ++pitch; \

        } else { \

            --pitch; \

        } \

        if (!draw_end) { \

            pixel += pitch; \

        } \

        length = (y1-y2); \

    } \

    if (draw_end) { \

        ++length; \

    } \

    while (length--) { \

        op; \

        pixel += pitch; \

    } \

}

/* Bresenham's line algorithm */

#define BLINE(x1, y1, x2, y2, op, draw_end) \

{ \

    int i, deltax, deltay, numpixels; \

    int d, dinc1, dinc2; \

    int x, xinc1, xinc2; \

    int y, yinc1, yinc2; \

 \

    deltax = ABS(x2 - x1); \

    deltay = ABS(y2 - y1); \

 \

    if (deltax >= deltay) { \

        numpixels = deltax + 1; \

        d = (2 * deltay) - deltax; \

        dinc1 = deltay * 2; \

        dinc2 = (deltay - deltax) * 2; \

        xinc1 = 1; \

        xinc2 = 1; \

        yinc1 = 0; \

        yinc2 = 1; \

    } else { \

        numpixels = deltay + 1; \

        d = (2 * deltax) - deltay; \

        dinc1 = deltax * 2; \

        dinc2 = (deltax - deltay) * 2; \

        xinc1 = 0; \

        xinc2 = 1; \

        yinc1 = 1; \

        yinc2 = 1; \

    } \

 \

    if (x1 > x2) { \

        xinc1 = -xinc1; \

        xinc2 = -xinc2; \

    } \

    if (y1 > y2) { \

        yinc1 = -yinc1; \

        yinc2 = -yinc2; \

    } \

 \

    x = x1; \

    y = y1; \

 \

    if (!draw_end) { \

        --numpixels; \

    } \

    for (i = 0; i < numpixels; ++i) { \

        op(x, y); \

        if (d < 0) { \

            d += dinc1; \

            x += xinc1; \

            y += yinc1; \

        } else { \

            d += dinc2; \

            x += xinc2; \

            y += yinc2; \

        } \

    } \

}

/* Xiaolin Wu's line algorithm, based on Michael Abrash's implementation */

#define WULINE(x1, y1, x2, y2, opaque_op, blend_op, draw_end) \

{ \

    Uint16 ErrorAdj, ErrorAcc; \

    Uint16 ErrorAccTemp, Weighting; \

    int DeltaX, DeltaY, Temp, XDir; \

    unsigned r, g, b, a, inva; \

 \

    /* Draw the initial pixel, which is always exactly intersected by \

       the line and so needs no weighting */ \

    opaque_op(x1, y1); \

 \

    /* Draw the final pixel, which is always exactly intersected by the line \

       and so needs no weighting */ \

    if (draw_end) { \

        opaque_op(x2, y2); \

    } \

 \

    /* Make sure the line runs top to bottom */ \

    if (y1 > y2) { \

        Temp = y1; y1 = y2; y2 = Temp; \

        Temp = x1; x1 = x2; x2 = Temp; \

    } \

    DeltaY = y2 - y1; \

 \

    if ((DeltaX = x2 - x1) >= 0) { \

        XDir = 1; \

    } else { \

        XDir = -1; \

        DeltaX = -DeltaX; /* make DeltaX positive */ \

    } \

 \

    /* line is not horizontal, diagonal, or vertical */ \

    ErrorAcc = 0;  /* initialize the line error accumulator to 0 */ \

 \

    /* Is this an X-major or Y-major line? */ \

    if (DeltaY > DeltaX) { \

        /* Y-major line; calculate 16-bit fixed-point fractional part of a \

          pixel that X advances each time Y advances 1 pixel, truncating the \

          result so that we won't overrun the endpoint along the X axis */ \

        ErrorAdj = ((unsigned long) DeltaX << 16) / (unsigned long) DeltaY; \

        /* Draw all pixels other than the first and last */ \

        while (--DeltaY) { \

            ErrorAccTemp = ErrorAcc;   /* remember currrent accumulated error */ \

            ErrorAcc += ErrorAdj;      /* calculate error for next pixel */ \

            if (ErrorAcc <= ErrorAccTemp) { \

                /* The error accumulator turned over, so advance the X coord */ \

                x1 += XDir; \

            } \

            y1++; /* Y-major, so always advance Y */ \

            /* The IntensityBits most significant bits of ErrorAcc give us the \

             intensity weighting for this pixel, and the complement of the \

             weighting for the paired pixel */ \

            Weighting = ErrorAcc >> 8; \

            { \

                a = DRAW_MUL(_a, (Weighting ^ 255)); \

                r = DRAW_MUL(_r, a); \

                g = DRAW_MUL(_g, a); \

                b = DRAW_MUL(_b, a); \

                inva = (a ^ 0xFF); \

                blend_op(x1, y1); \

            } \

            { \

                a = DRAW_MUL(_a, Weighting); \

                r = DRAW_MUL(_r, a); \

                g = DRAW_MUL(_g, a); \

                b = DRAW_MUL(_b, a); \

                inva = (a ^ 0xFF); \

                blend_op(x1 + XDir, y1); \

            } \

        } \

    } else { \

        /* X-major line; calculate 16-bit fixed-point fractional part of a \

           pixel that Y advances each time X advances 1 pixel, truncating the \

           result to avoid overrunning the endpoint along the X axis */ \

        ErrorAdj = ((unsigned long) DeltaY << 16) / (unsigned long) DeltaX; \

        /* Draw all pixels other than the first and last */ \

        while (--DeltaX) { \

            ErrorAccTemp = ErrorAcc;   /* remember currrent accumulated error */ \

            ErrorAcc += ErrorAdj;      /* calculate error for next pixel */ \

            if (ErrorAcc <= ErrorAccTemp) { \

                /* The error accumulator turned over, so advance the Y coord */ \

                y1++; \

            } \

            x1 += XDir; /* X-major, so always advance X */ \

            /* The IntensityBits most significant bits of ErrorAcc give us the \

              intensity weighting for this pixel, and the complement of the \

              weighting for the paired pixel */ \

            Weighting = ErrorAcc >> 8; \

            { \

                a = DRAW_MUL(_a, (Weighting ^ 255)); \

                r = DRAW_MUL(_r, a); \

                g = DRAW_MUL(_g, a); \

                b = DRAW_MUL(_b, a); \

                inva = (a ^ 0xFF); \

                blend_op(x1, y1); \

            } \

            { \

                a = DRAW_MUL(_a, Weighting); \

                r = DRAW_MUL(_r, a); \

                g = DRAW_MUL(_g, a); \

                b = DRAW_MUL(_b, a); \

                inva = (a ^ 0xFF); \

                blend_op(x1, y1 + 1); \

            } \

        } \

    } \

}

#ifdef AA_LINES

#define AALINE(x1, y1, x2, y2, opaque_op, blend_op, draw_end) \

            WULINE(x1, y1, x2, y2, opaque_op, blend_op, draw_end)

#else

#define AALINE(x1, y1, x2, y2, opaque_op, blend_op, draw_end) \

            BLINE(x1, y1, x2, y2, opaque_op, draw_end)

#endif

/*

 * Define fill rect macro

 */

#define FILLRECT(type, op) \

do { \

    int width = rect->w; \

    int height = rect->h; \

    int pitch = (dst->pitch / dst->format->BytesPerPixel); \

    int skip = pitch - width; \

    type *pixel = (type *)dst->pixels + rect->y * pitch + rect->x; \

    while (height--) { \

        { int n = (width+3)/4; \

            switch (width & 3) { \

            case 0: do {   op; pixel++; \

            case 3:        op; pixel++; \

            case 2:        op; pixel++; \

            case 1:        op; pixel++; \

                    } while ( --n > 0 ); \

            } \

        } \

        pixel += skip; \

    } \

} while (0)

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