+static void draw_pieces(ModeInfo *mi, Chesscreen *cs, int wire)
+{
+ if (!cs->wire) {
+ glEnable(GL_TEXTURE_2D);
+ glBindTexture(GL_TEXTURE_2D, cs->piecetexture);
+ glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+
+ glColor4f(0.5, 0.5, 0.5, 1.0);
+ glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialShadow);
+ }
+
+ drawPieces(mi, cs);
+ if(cs->moving) drawMovingPiece(mi, cs, 0);
+ if(cs->take) drawTakePiece(mi, cs, 0);
+ glDisable(GL_TEXTURE_2D);
+}
+
+static void draw_shadow_pieces(ModeInfo *mi, Chesscreen *cs, int wire)
+{
+ if (!cs->wire) {
+ glEnable(GL_TEXTURE_2D);
+ glBindTexture(GL_TEXTURE_2D, cs->piecetexture);
+ glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+ }
+
+ /* use the stencil */
+ glDisable(GL_LIGHTING);
+ glDisable(GL_COLOR_MATERIAL);
+ glDisable(GL_DEPTH_TEST);
+ glDisable(GL_TEXTURE_2D);
+ glDisable(GL_BLEND);
+
+ glClear(GL_STENCIL_BUFFER_BIT);
+ glColorMask(0,0,0,0);
+ glEnable(GL_STENCIL_TEST);
+
+ glStencilFunc(GL_ALWAYS, 1, 0xFFFFFFFFL);
+ glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
+
+
+ glPushMatrix();
+ glTranslatef(0.0, 0.001, 0.0);
+
+ /* draw the pieces */
+ drawPiecesShadow(mi, cs);
+ if(cs->moving) drawMovingPiece(mi, cs, shadows);
+ if(cs->take) drawTakePiece(mi, cs, shadows);
+
+ glPopMatrix();
+
+
+ /* turn on drawing into colour buffer */
+ glColorMask(1,1,1,1);
+
+ /* programming with effect */
+ glDisable(GL_LIGHTING);
+ glDisable(GL_COLOR_MATERIAL);
+ glDisable(GL_TEXTURE_2D);
+
+ /* now draw the union of the shadows */
+
+ /*
+ <todo>
+ want to keep alpha values (alpha is involved in transition
+ effects of the active pieces).
+ </todo>
+ */
+ glStencilFunc(GL_NOTEQUAL, 0, 0xFFFFFFFFL);
+ glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
+
+ glEnable(GL_BLEND);
+
+ glColor4fv(MaterialShadow);
+
+ /* draw the board generously to fill the shadows */
+ glBegin(GL_QUADS);
+
+ glVertex3f(-1.0, 0.0, -1.0);
+ glVertex3f(-1.0, 0.0, BOARDSIZE + 1.0);
+ glVertex3f(1.0 + BOARDSIZE, 0.0, BOARDSIZE + 1.0);
+ glVertex3f(1.0 + BOARDSIZE, 0.0, -1.0);
+
+ glEnd();
+
+ glDisable(GL_STENCIL_TEST);
+
+ /* "pop" attributes */
+ glEnable(GL_TEXTURE_2D);
+ glEnable(GL_COLOR_MATERIAL);
+ glEnable(GL_LIGHTING);
+ glEnable(GL_CULL_FACE);
+
+
+
+}