{$INCLUDE "options.inc"}

unit uTextures;

interface

uses SDLh, uTypes;

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

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

procedure FreeTexture(tex: PTexture);

procedure initModule;

procedure freeModule;

implementation

uses GLunit, uUtils, uVariables, uConsts, uDebug;

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;

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

var tw, th, x, y: Longword;

    tmpp: pointer;

    fromP4, toP4: PLongWordArray;

begin

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);

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;

    GetMem(tmpp, 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]:= 0;

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

        fromP4:= @(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:= @(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

procedure FreeTexture(tex: PTexture);

begin

    if tex <> nil then

    begin

        if tex^.NextTexture <> nil then

            tex^.NextTexture^.PrevTexture:= tex^.PrevTexture;

        if tex^.PrevTexture <> nil then

            tex^.PrevTexture^.NextTexture:= tex^.NextTexture

        else

            TextureList:= tex^.NextTexture;

        glDeleteTextures(1, @tex^.id);

        Dispose(tex);

    end

end;

procedure initModule;

begin

TextureList:= nil;

end;

procedure freeModule;

begin

    while TextureList <> nil do FreeTexture(TextureList);

end;

end.