(*

 * Hedgewars, a free turn based strategy game

 * Copyright (c) 2004-2014 Andrey Korotaev <unC0Rr@gmail.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; version 2 of the License

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

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

 *)

{$INCLUDE "options.inc"}

unit uTextures;

interface

uses SDLh, uTypes;

function  NewTexture(width, height: Longword; buf: Pointer): PTexture;

procedure Surface2GrayScale(surf: PSDL_Surface);

function  Surface2Tex(surf: PSDL_Surface; enableClamp: boolean): PTexture;

procedure PrettifySurfaceAlpha(surf: PSDL_Surface; pixels: PLongwordArray);

procedure PrettifyAlpha2D(pixels: TLandArray; height, width: LongWord);

procedure initModule;

procedure freeModule;

implementation

uses GLunit, uUtils, uVariables, uConsts, uDebug, uConsole;

var TextureList: PTexture;

procedure SetTextureParameters(enableClamp: Boolean);

begin

    if enableClamp and ((cReducedQuality and rqClampLess) = 0) then

        begin

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE)

        end;

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)

end;

procedure ResetVertexArrays(texture: PTexture);

begin

with texture^ do

    begin

    vb[0].X:= 0;

    vb[0].Y:= 0;

    vb[1].X:= w;

    vb[1].Y:= 0;

    vb[2].X:= w;

    vb[2].Y:= h;

    vb[3].X:= 0;

    vb[3].Y:= h;

    tb[0].X:= 0;

    tb[0].Y:= 0;

    tb[1].X:= rx;

    tb[1].Y:= 0;

    tb[2].X:= rx;

    tb[2].Y:= ry;

    tb[3].X:= 0;

    tb[3].Y:= ry

    end;

end;

function NewTexture(width, height: Longword; buf: Pointer): PTexture;

begin

new(NewTexture);

NewTexture^.PrevTexture:= nil;

NewTexture^.NextTexture:= nil;

NewTexture^.Scale:= 1;

if TextureList <> nil then

    begin

    TextureList^.PrevTexture:= NewTexture;

    NewTexture^.NextTexture:= TextureList

    end;

TextureList:= NewTexture;

NewTexture^.w:= width;

NewTexture^.h:= height;

NewTexture^.rx:= 1.0;

NewTexture^.ry:= 1.0;

ResetVertexArrays(NewTexture);

glGenTextures(1, @NewTexture^.id);

glBindTexture(GL_TEXTURE_2D, NewTexture^.id);

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, buf);

SetTextureParameters(true);

end;

procedure Surface2GrayScale(surf: PSDL_Surface);

var tw, x, y: Longword;

    fromP4: PLongWordArray;

begin

fromP4:= Surf^.pixels;

for y:= 0 to Pred(Surf^.h) do

    begin

    for x:= 0 to Pred(Surf^.w) do

        begin

        tw:= fromP4^[x];

        tw:= round((tw shr RShift and $FF) * RGB_LUMINANCE_RED +

              (tw shr GShift and $FF) * RGB_LUMINANCE_GREEN +

              (tw shr BShift and $FF) * RGB_LUMINANCE_BLUE);

        if tw > 255 then tw:= 255;

        tw:= (tw and $FF shl RShift) or (tw and $FF shl BShift) or (tw and $FF shl GShift) or (fromP4^[x] and AMask);

        fromP4^[x]:= tw;

        end;

    fromP4:= PLongWordArray(@(fromP4^[Surf^.pitch div 4]))

    end;

end;

{ this will make invisible pixels that have a visible neighbor have the

  same color as their visible neighbor, so that bilinear filtering won't

  display a "wrongly" colored border when zoomed in }

procedure PrettifyAlpha(row1, row2: PLongwordArray; firsti, lasti, ioffset: LongWord);

var

    i: Longword;

    lpi, cpi, bpi: boolean; // was last/current/bottom neighbor pixel invisible?

begin

    // suppress incorrect warning

    lpi:= true;

    for i:=firsti to lasti do

        begin

        // use first pixel in row1 as starting point

        if i = firsti then

            cpi:= ((row1^[i] and AMask) = 0)

        else

            begin

            cpi:= ((row1^[i] and AMask) = 0);

            if cpi <> lpi then

                begin

                // invisible pixels get colors from visible neighbors

                if cpi then

                    begin

                    row1^[i]:= row1^[i-1] and (not AMask);

                    // as this pixel is invisible and already colored correctly now, no point in further comparing it

                    lpi:= cpi;

                    continue;

                    end

                else

                    row1^[i-1]:= row1^[i] and (not AMask);

                end;

            end;

        lpi:= cpi;

        // also check bottom neighbor

        if row2 <> nil then

            begin

            bpi:= ((row2^[i+ioffset] and AMask) = 0);

            if cpi <> bpi then

                begin

                if cpi then

                    row1^[i]:= row2^[i+ioffset] and (not AMask)

                else

                    row2^[i+ioffset]:= row1^[i] and (not AMask);

                end;

            end;

        end;

end;

procedure PrettifySurfaceAlpha(surf: PSDL_Surface; pixels: PLongwordArray);

var

    // current row index, second last row index of array, width and first/last i of row

    r, slr, w, si, li: LongWord;

begin

    w:= surf^.w;

    slr:= surf^.h - 2;

    si:= 0;

    li:= w - 1;

    for r:= 0 to slr do

        begin

        PrettifyAlpha(pixels, pixels, si, li, w);

        // move indices to next row

        si:= si + w;

        li:= li + w;

        end;

    // don't forget last row

    PrettifyAlpha(pixels, nil, si, li, w);

end;

procedure PrettifyAlpha2D(pixels: TLandArray; height, width: LongWord);

var

    // current y; last x, second last y of array;

    y, lx, sly: LongWord;

begin

    sly:= height - 2;

    lx:= width - 1;

    for y:= 0 to sly do

        begin

        PrettifyAlpha(PLongWordArray(pixels[y]), PLongWordArray(pixels[y+1]), 0, lx, 0);

        end;

    // don't forget last row

    PrettifyAlpha(PLongWordArray(pixels[sly+1]), nil, 0, lx, 0);

end;

function Surface2Tex(surf: PSDL_Surface; enableClamp: boolean): PTexture;

var tw, th, x, y: Longword;

    tmpp: pointer;

    fromP4, toP4: PLongWordArray;

begin

if cOnlyStats then exit(nil);

new(Surface2Tex);

Surface2Tex^.PrevTexture:= nil;

Surface2Tex^.NextTexture:= nil;

if TextureList <> nil then

    begin

    TextureList^.PrevTexture:= Surface2Tex;

    Surface2Tex^.NextTexture:= TextureList

    end;

TextureList:= Surface2Tex;

Surface2Tex^.w:= surf^.w;

Surface2Tex^.h:= surf^.h;

if (surf^.format^.BytesPerPixel <> 4) then

    begin

    TryDo(false, 'Surface2Tex failed, expecting 32 bit surface', true);

    Surface2Tex^.id:= 0;

    exit

    end;

glGenTextures(1, @Surface2Tex^.id);

glBindTexture(GL_TEXTURE_2D, Surface2Tex^.id);

if SDL_MustLock(surf) then

    SDLTry(SDL_LockSurface(surf) >= 0, true);

fromP4:= Surf^.pixels;

if GrayScale then

    Surface2GrayScale(Surf);

PrettifySurfaceAlpha(surf, fromP4);

if (not SupportNPOTT) and (not (isPowerOf2(Surf^.w) and isPowerOf2(Surf^.h))) then

    begin

    tw:= toPowerOf2(Surf^.w);

    th:= toPowerOf2(Surf^.h);

    Surface2Tex^.rx:= Surf^.w / tw;

    Surface2Tex^.ry:= Surf^.h / th;

    tmpp:= GetMem(tw * th * surf^.format^.BytesPerPixel);

    fromP4:= Surf^.pixels;

    toP4:= tmpp;

    for y:= 0 to Pred(Surf^.h) do

        begin

        for x:= 0 to Pred(Surf^.w) do

            toP4^[x]:= fromP4^[x];

        for x:= Surf^.w to Pred(tw) do

            toP4^[x]:= fromP4^[0];

        toP4:= PLongWordArray(@(toP4^[tw]));

        fromP4:= PLongWordArray(@(fromP4^[Surf^.pitch div 4]))

        end;

    for y:= Surf^.h to Pred(th) do

        begin

        for x:= 0 to Pred(tw) do

            toP4^[x]:= 0;

        toP4:= PLongWordArray(@(toP4^[tw]))

        end;

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tw, th, 0, GL_RGBA, GL_UNSIGNED_BYTE, tmpp);

    FreeMem(tmpp, tw * th * surf^.format^.BytesPerPixel)

    end

else

    begin

    Surface2Tex^.rx:= 1.0;

    Surface2Tex^.ry:= 1.0;

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, surf^.w, surf^.h, 0, GL_RGBA, GL_UNSIGNED_BYTE, surf^.pixels);

    end;

ResetVertexArrays(Surface2Tex);

if SDL_MustLock(surf) then

    SDL_UnlockSurface(surf);

SetTextureParameters(enableClamp);

end;

// deletes texture and frees the memory allocated for it.

// if nil is passed nothing is done

begin

end;

procedure initModule;

begin

TextureList:= nil;

end;

procedure freeModule;

begin

if TextureList <> nil then

    WriteToConsole('FIXME FIXME FIXME. App shutdown without full cleanup of texture list; read game0.log and please report this problem');

    while TextureList <> nil do

        begin

        end

end;

end.