--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hedgewars/uMatrix.pas	Sun Nov 11 17:15:19 2012 +0100
@@ -0,0 +1,268 @@
+(*
+ * Hedgewars, a free turn based strategy game
+ * Copyright (c) 2004-2012 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *)
+
+{$INCLUDE "options.inc"}
+
+unit uMatrix;
+
+interface
+
+uses uTypes {$IFNDEF PAS2C}, gl{$ENDIF};
+
+const
+    MATRIX_MODELVIEW:Integer = 0;
+    MATRIX_PROJECTION:Integer = 1;
+  
+procedure MatrixLoadIdentity(out Result: TMatrix4x4f);
+procedure MatrixMultiply(out Result: TMatrix4x4f; const lhs, rhs: TMatrix4x4f);
+
+procedure hglMatrixMode(t: Integer);
+procedure hglLoadIdentity();
+procedure hglPushMatrix();
+procedure hglPopMatrix();
+procedure hglMVP(var res : TMatrix4x4f);
+procedure hglScalef(x: GLfloat; y: GLfloat; z: GLfloat);
+procedure hglTranslatef(x: GLfloat; y: GLfloat; z: GLfloat);
+procedure hglRotatef(a:GLfloat; x:GLfloat; y:GLfloat; z:GLfloat);
+procedure initModule();
+procedure freeModule();
+
+implementation
+
+const
+    MATRIX_STACK_SIZE = 10;
+
+type
+    TMatrixStack = record
+        top:Integer;
+        stack: array[0..9] of TMatrix4x4f;
+        end;
+var
+    MatrixStacks : array[0..1] of TMatrixStack;
+    CurMatrix: integer;
+
+procedure MatrixLoadIdentity(out Result: TMatrix4x4f);
+begin
+    Result[0,0]:= 1.0; Result[1,0]:=0.0; Result[2,0]:=0.0; Result[3,0]:=0.0;
+    Result[0,1]:= 0.0; Result[1,1]:=1.0; Result[2,1]:=0.0; Result[3,1]:=0.0;
+    Result[0,2]:= 0.0; Result[1,2]:=0.0; Result[2,2]:=1.0; Result[3,2]:=0.0;
+    Result[0,3]:= 0.0; Result[1,3]:=0.0; Result[2,3]:=0.0; Result[3,3]:=1.0;
+end;
+
+procedure hglMatrixMode(t: Integer);
+begin
+    CurMatrix := t;
+end;
+
+procedure hglLoadIdentity();
+begin
+    MatrixLoadIdentity(MatrixStacks[CurMatrix].stack[MatrixStacks[CurMatrix].top]);
+end;
+
+procedure hglScalef(x: GLfloat; y: GLfloat; z: GLfloat);
+var
+    m:TMatrix4x4f;
+    t:TMatrix4x4f;
+begin
+    m[0,0]:=x;m[1,0]:=0;m[2,0]:=0;m[3,0]:=0;
+    m[0,1]:=0;m[1,1]:=y;m[2,1]:=0;m[3,1]:=0;
+    m[0,2]:=0;m[1,2]:=0;m[2,2]:=z;m[3,2]:=0;
+    m[0,3]:=0;m[1,3]:=0;m[2,3]:=0;m[3,3]:=1;
+
+    MatrixMultiply(t, MatrixStacks[CurMatrix].stack[MatrixStacks[CurMatrix].top], m);
+    MatrixStacks[CurMatrix].stack[MatrixStacks[CurMatrix].top] := t; 
+end;
+
+procedure hglTranslatef(x: GLfloat; y: GLfloat; z: GLfloat);
+var
+    m:TMatrix4x4f;
+    t:TMatrix4x4f;
+begin
+    m[0,0]:=1;m[1,0]:=0;m[2,0]:=0;m[3,0]:=x;
+    m[0,1]:=0;m[1,1]:=1;m[2,1]:=0;m[3,1]:=y;
+    m[0,2]:=0;m[1,2]:=0;m[2,2]:=1;m[3,2]:=z;
+    m[0,3]:=0;m[1,3]:=0;m[2,3]:=0;m[3,3]:=1;
+
+    MatrixMultiply(t, MatrixStacks[CurMatrix].stack[MatrixStacks[CurMatrix].top], m);
+    MatrixStacks[CurMatrix].stack[MatrixStacks[CurMatrix].top] := t;
+end;
+
+procedure hglRotatef(a:GLfloat; x:GLfloat; y:GLfloat; z:GLfloat);
+var
+    m:TMatrix4x4f;
+    t:TMatrix4x4f;
+    c:GLfloat;
+    s:GLfloat;
+    xn, yn, zn:GLfloat;
+    l:GLfloat;
+begin
+    a:=a * 3.14159265368 / 180;
+    c:=cos(a);
+    s:=sin(a);
+    
+    l := 1.0 / sqrt(x * x + y * y + z * z);
+    xn := x * l;
+    yn := y * l;
+    zn := z * l;
+
+    m[0,0]:=c + xn * xn * (1 - c);
+    m[1,0]:=xn * yn * (1 - c) - zn * s;
+    m[2,0]:=xn * zn * (1 - c) + yn * s;
+    m[3,0]:=0;
+
+
+    m[0,1]:=yn * xn * (1 - c) + zn * s;
+    m[1,1]:=c + yn * yn * (1 - c);
+    m[2,1]:=yn * zn * (1 - c) - xn * s;
+    m[3,1]:=0;
+
+    m[0,2]:=zn * xn * (1 - c) - yn * s;
+    m[1,2]:=zn * yn * (1 - c) + xn * s;
+    m[2,2]:=c + zn * zn * (1 - c);
+    m[3,2]:=0;
+
+    m[0,3]:=0;m[1,3]:=0;m[2,3]:=0;m[3,3]:=1;
+
+    MatrixMultiply(t, MatrixStacks[CurMatrix].stack[MatrixStacks[CurMatrix].top], m);
+    MatrixStacks[CurMatrix].stack[MatrixStacks[CurMatrix].top] := t;
+end;
+
+procedure hglMVP(var res: TMatrix4x4f);
+begin
+    MatrixMultiply(res, 
+                   MatrixStacks[MATRIX_PROJECTION].stack[MatrixStacks[MATRIX_PROJECTION].top], 
+                   MatrixStacks[MATRIX_MODELVIEW].stack[MatrixStacks[MATRIX_MODELVIEW].top]);
+end;
+
+procedure hglPushMatrix();
+var
+    t: Integer;
+begin
+    t := MatrixStacks[CurMatrix].top;
+    MatrixStacks[CurMatrix].stack[t + 1] := MatrixStacks[CurMatrix].stack[t];
+    inc(t);
+    MatrixStacks[CurMatrix].top := t;
+end;
+
+procedure hglPopMatrix();
+var
+    t: Integer;
+begin
+    t := MatrixStacks[CurMatrix].top;
+    dec(t);
+    MatrixStacks[CurMatrix].top := t;
+end;
+
+procedure initModule();
+begin
+    MatrixStacks[MATRIX_MODELVIEW].top := 0;
+    MatrixStacks[MATRIX_Projection].top := 0;
+    MatrixLoadIdentity(MatrixStacks[MATRIX_MODELVIEW].stack[0]);
+    MatrixLoadIdentity(MatrixStacks[MATRIX_PROJECTION].stack[0]);
+end;
+
+procedure freeModule();
+begin
+end;
+
+procedure MatrixMultiply(out Result: TMatrix4x4f; const lhs, rhs: TMatrix4x4f);
+var
+    test: TMatrix4x4f;
+    i, j: Integer;
+    error: boolean;
+begin
+    Result[0,0]:=lhs[0,0]*rhs[0,0] + lhs[1,0]*rhs[0,1] + lhs[2,0]*rhs[0,2] + lhs[3,0]*rhs[0,3];
+    Result[0,1]:=lhs[0,1]*rhs[0,0] + lhs[1,1]*rhs[0,1] + lhs[2,1]*rhs[0,2] + lhs[3,1]*rhs[0,3];
+    Result[0,2]:=lhs[0,2]*rhs[0,0] + lhs[1,2]*rhs[0,1] + lhs[2,2]*rhs[0,2] + lhs[3,2]*rhs[0,3];
+    Result[0,3]:=lhs[0,3]*rhs[0,0] + lhs[1,3]*rhs[0,1] + lhs[2,3]*rhs[0,2] + lhs[3,3]*rhs[0,3];
+
+    Result[1,0]:=lhs[0,0]*rhs[1,0] + lhs[1,0]*rhs[1,1] + lhs[2,0]*rhs[1,2] + lhs[3,0]*rhs[1,3];
+    Result[1,1]:=lhs[0,1]*rhs[1,0] + lhs[1,1]*rhs[1,1] + lhs[2,1]*rhs[1,2] + lhs[3,1]*rhs[1,3];
+    Result[1,2]:=lhs[0,2]*rhs[1,0] + lhs[1,2]*rhs[1,1] + lhs[2,2]*rhs[1,2] + lhs[3,2]*rhs[1,3];
+    Result[1,3]:=lhs[0,3]*rhs[1,0] + lhs[1,3]*rhs[1,1] + lhs[2,3]*rhs[1,2] + lhs[3,3]*rhs[1,3];
+
+    Result[2,0]:=lhs[0,0]*rhs[2,0] + lhs[1,0]*rhs[2,1] + lhs[2,0]*rhs[2,2] + lhs[3,0]*rhs[2,3];
+    Result[2,1]:=lhs[0,1]*rhs[2,0] + lhs[1,1]*rhs[2,1] + lhs[2,1]*rhs[2,2] + lhs[3,1]*rhs[2,3];
+    Result[2,2]:=lhs[0,2]*rhs[2,0] + lhs[1,2]*rhs[2,1] + lhs[2,2]*rhs[2,2] + lhs[3,2]*rhs[2,3];
+    Result[2,3]:=lhs[0,3]*rhs[2,0] + lhs[1,3]*rhs[2,1] + lhs[2,3]*rhs[2,2] + lhs[3,3]*rhs[2,3];
+
+    Result[3,0]:=lhs[0,0]*rhs[3,0] + lhs[1,0]*rhs[3,1] + lhs[2,0]*rhs[3,2] + lhs[3,0]*rhs[3,3];
+    Result[3,1]:=lhs[0,1]*rhs[3,0] + lhs[1,1]*rhs[3,1] + lhs[2,1]*rhs[3,2] + lhs[3,1]*rhs[3,3];
+    Result[3,2]:=lhs[0,2]*rhs[3,0] + lhs[1,2]*rhs[3,1] + lhs[2,2]*rhs[3,2] + lhs[3,2]*rhs[3,3];
+    Result[3,3]:=lhs[0,3]*rhs[3,0] + lhs[1,3]*rhs[3,1] + lhs[2,3]*rhs[3,2] + lhs[3,3]*rhs[3,3];
+
+{
+    Result[0,0]:=lhs[0,0]*rhs[0,0] + lhs[1,0]*rhs[0,1] + lhs[2,0]*rhs[0,2] + lhs[3,0]*rhs[0,3];
+    Result[0,1]:=lhs[0,0]*rhs[1,0] + lhs[1,0]*rhs[1,1] + lhs[2,0]*rhs[1,2] + lhs[3,0]*rhs[1,3];
+    Result[0,2]:=lhs[0,0]*rhs[2,0] + lhs[1,0]*rhs[2,1] + lhs[2,0]*rhs[2,2] + lhs[3,0]*rhs[2,3];
+    Result[0,3]:=lhs[0,0]*rhs[3,0] + lhs[1,0]*rhs[3,1] + lhs[2,0]*rhs[3,2] + lhs[3,0]*rhs[3,3];
+  
+    Result[1,0]:=lhs[0,1]*rhs[0,0] + lhs[1,1]*rhs[0,1] + lhs[2,1]*rhs[0,2] + lhs[3,1]*rhs[0,3];
+    Result[1,1]:=lhs[0,1]*rhs[1,0] + lhs[1,1]*rhs[1,1] + lhs[2,1]*rhs[1,2] + lhs[3,1]*rhs[1,3];
+    Result[1,2]:=lhs[0,1]*rhs[2,0] + lhs[1,1]*rhs[2,1] + lhs[2,1]*rhs[2,2] + lhs[3,1]*rhs[2,3];
+    Result[1,3]:=lhs[0,1]*rhs[3,0] + lhs[1,1]*rhs[3,1] + lhs[2,1]*rhs[3,2] + lhs[3,1]*rhs[3,3];
+
+    Result[2,0]:=lhs[0,2]*rhs[0,0] + lhs[1,2]*rhs[0,1] + lhs[2,2]*rhs[0,2] + lhs[3,2]*rhs[0,3];
+    Result[2,1]:=lhs[0,2]*rhs[1,0] + lhs[1,2]*rhs[1,1] + lhs[2,2]*rhs[1,2] + lhs[3,2]*rhs[1,3];
+    Result[2,2]:=lhs[0,2]*rhs[2,0] + lhs[1,2]*rhs[2,1] + lhs[2,2]*rhs[2,2] + lhs[3,2]*rhs[2,3];
+    Result[2,3]:=lhs[0,2]*rhs[3,0] + lhs[1,2]*rhs[3,1] + lhs[2,2]*rhs[3,2] + lhs[3,2]*rhs[3,3];
+
+    Result[3,0]:=lhs[0,3]*rhs[0,0] + lhs[1,3]*rhs[0,1] + lhs[2,3]*rhs[0,2] + lhs[3,3]*rhs[0,3];
+    Result[3,1]:=lhs[0,3]*rhs[1,0] + lhs[1,3]*rhs[1,1] + lhs[2,3]*rhs[1,2] + lhs[3,3]*rhs[1,3];
+    Result[3,2]:=lhs[0,3]*rhs[2,0] + lhs[1,3]*rhs[2,1] + lhs[2,3]*rhs[2,2] + lhs[3,3]*rhs[2,3];
+    Result[3,3]:=lhs[0,3]*rhs[3,0] + lhs[1,3]*rhs[3,1] + lhs[2,3]*rhs[3,2] + lhs[3,3]*rhs[3,3];
+}
+
+    {$IFNDEF PAS2C}
+    glPushMatrix;
+    glLoadMatrixf(@lhs[0, 0]);
+    glMultMatrixf(@rhs[0, 0]);
+    glGetFloatv(GL_MODELVIEW_MATRIX, @test[0, 0]);
+    glPopMatrix;
+
+    error:=false;
+    for i:=0 to 3 do
+      for j:=0 to 3 do
+        if Abs(test[i, j] - Result[i, j]) > 0.000001 then
+          error:=true;
+
+    if error then
+    begin
+        writeln('shall:');
+        for i:=0 to 3 do
+        begin
+          for j:=0 to 3 do
+            write(test[i, j]);
+          writeln;
+        end;
+
+        writeln('is:');
+        for i:=0 to 3 do
+        begin
+          for j:=0 to 3 do
+            write(Result[i, j]);
+          writeln;
+        end;
+        halt(0);
+    end;
+    {$ENDIF}
+
+end;
+
+
+end.