/*

  Simple DirectMedia Layer

  Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied

  warranty.  In no event will the authors be held liable for any damages

  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,

  including commercial applications, and to alter it and redistribute it

  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not

     claim that you wrote the original software. If you use this software

     in a product, an acknowledgment in the product documentation would be

     appreciated but is not required.

  2. Altered source versions must be plainly marked as such, and must not be

     misrepresented as being the original software.

  3. This notice may not be removed or altered from any source distribution.

*/

#include "SDL_config.h"

#if !SDL_RENDER_DISABLED

#include "SDL_draw.h"

#include "SDL_drawline.h"

#include "SDL_drawpoint.h"

static void

SDL_DrawLine1(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color,

              SDL_bool draw_end)

{

    if (y1 == y2) {

        //HLINE(Uint8, DRAW_FASTSETPIXEL1, draw_end);

        int length;

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

        Uint8 *pixel;

        if (x1 <= x2) {

            pixel = (Uint8 *)dst->pixels + y1 * pitch + x1;

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

        } else {

            pixel = (Uint8 *)dst->pixels + y1 * pitch + x2;

            if (!draw_end) {

                ++pixel;

            }

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

        }

        SDL_memset(pixel, color, length);

    } else if (x1 == x2) {

        VLINE(Uint8, DRAW_FASTSETPIXEL1, draw_end);

    } else if (ABS(x1 - x2) == ABS(y1 - y2)) {

        DLINE(Uint8, DRAW_FASTSETPIXEL1, draw_end);

    } else {

        BLINE(x1, y1, x2, y2, DRAW_FASTSETPIXELXY1, draw_end);

    }

}

static void

SDL_DrawLine2(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color,

              SDL_bool draw_end)

{

    if (y1 == y2) {

        HLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end);

    } else if (x1 == x2) {

        VLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end);

    } else if (ABS(x1 - x2) == ABS(y1 - y2)) {

        DLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end);

    } else {

        Uint8 _r, _g, _b, _a;

        const SDL_PixelFormat * fmt = dst->format;

        SDL_GetRGBA(color, fmt, &_r, &_g, &_b, &_a);

        if (fmt->Rmask == 0x7C00) {

            AALINE(x1, y1, x2, y2,

                   DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY_BLEND_RGB555,

                   draw_end);

        } else if (fmt->Rmask == 0xF800) {

            AALINE(x1, y1, x2, y2,

                   DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY_BLEND_RGB565,

                   draw_end);

        } else {

            AALINE(x1, y1, x2, y2,

                   DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY2_BLEND_RGB,

                   draw_end);

        }

    }

}

static void

SDL_DrawLine4(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color,

              SDL_bool draw_end)

{

    if (y1 == y2) {

        HLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end);

    } else if (x1 == x2) {

        VLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end);

    } else if (ABS(x1 - x2) == ABS(y1 - y2)) {

        DLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end);

    } else {

        Uint8 _r, _g, _b, _a;

        const SDL_PixelFormat * fmt = dst->format;

        SDL_GetRGBA(color, fmt, &_r, &_g, &_b, &_a);

        if (fmt->Rmask == 0x00FF0000) {

            if (!fmt->Amask) {

                AALINE(x1, y1, x2, y2,

                       DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY_BLEND_RGB888,

                       draw_end);

            } else {

                AALINE(x1, y1, x2, y2,

                       DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY_BLEND_ARGB8888,

                       draw_end);

            }

        } else {

            AALINE(x1, y1, x2, y2,

                   DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY4_BLEND_RGB,

                   draw_end);

        }

    }

}

typedef void (*DrawLineFunc) (SDL_Surface * dst,

                              int x1, int y1, int x2, int y2,

                              Uint32 color, SDL_bool draw_end);

static DrawLineFunc

SDL_CalculateDrawLineFunc(const SDL_PixelFormat * fmt)

{

    switch (fmt->BytesPerPixel) {

    case 1:

        if (fmt->BitsPerPixel < 8) {

            break;

        }

        return SDL_DrawLine1;

    case 2:

        return SDL_DrawLine2;

    case 4:

        return SDL_DrawLine4;

    }

    return NULL;

}

int

SDL_DrawLine(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color)

{

    DrawLineFunc func;

    if (!dst) {

        SDL_SetError("SDL_DrawLine(): Passed NULL destination surface");

        return -1;

    }

    func = SDL_CalculateDrawLineFunc(dst->format);

    if (!func) {

        SDL_SetError("SDL_DrawLine(): Unsupported surface format");

        return -1;

    }

    /* Perform clipping */

    /* FIXME: We don't actually want to clip, as it may change line slope */

    if (!SDL_IntersectRectAndLine(&dst->clip_rect, &x1, &y1, &x2, &y2)) {

        return 0;

    }

    func(dst, x1, y1, x2, y2, color, SDL_TRUE);

    return 0;

}

int

SDL_DrawLines(SDL_Surface * dst, const SDL_Point * points, int count,

              Uint32 color)

{

    int i;

    int x1, y1;

    int x2, y2;

    SDL_bool draw_end;

    DrawLineFunc func;

    if (!dst) {

        SDL_SetError("SDL_DrawLines(): Passed NULL destination surface");

        return -1;

    }

    func = SDL_CalculateDrawLineFunc(dst->format);

    if (!func) {

        SDL_SetError("SDL_DrawLines(): Unsupported surface format");

        return -1;

    }

    for (i = 1; i < count; ++i) {

        x1 = points[i-1].x;

        y1 = points[i-1].y;

        x2 = points[i].x;

        y2 = points[i].y;

        /* Perform clipping */

        /* FIXME: We don't actually want to clip, as it may change line slope */

        if (!SDL_IntersectRectAndLine(&dst->clip_rect, &x1, &y1, &x2, &y2)) {

            continue;

        }

        /* Draw the end if it was clipped */

        draw_end = (x2 != points[i].x || y2 != points[i].y);

        func(dst, x1, y1, x2, y2, color, draw_end);

    }

    if (points[0].x != points[count-1].x || points[0].y != points[count-1].y) {

        SDL_DrawPoint(dst, points[count-1].x, points[count-1].y, color);

    }

    return 0;

}

#endif /* !SDL_RENDER_DISABLED */

/* vi: set ts=4 sw=4 expandtab: */