[JAVA2D] Texturing a trapezoid (fake 3d engine)

[orange451]

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double top1 =    Math.round(this.tempy + (this.newCamera.camz - this.z * 9.0D) * this.scale1);             double top2 =    Math.round(this.tempy + (this.newCamera.camz - this.z * 9.0D) * this.scale2);             double bottom1 = Math.round(this.tempy + (this.newCamera.camz - this.z * 9.0D) * this.scale3);             double bottom2 = Math.round(this.tempy + (this.newCamera.camz - this.z * 9.0D) * this.scale4);                         if (                   (point1 > view_width && point2 > view_width && point3 > view_width && point4 > view_width) ||                   (top1 > view_height && top2 > view_height && bottom1 > view_height && bottom2 > view_height) ||                   (top1 <= 0 && top2 <= 0 && bottom1 <= 0 && bottom2 <= 0) ||                   (point1 <= 0 && point2 <= 0 && point3 <= 0 && point4 <= 0)                   ){                   return;             }             double length = point_distance(point1, top1, point2, top2);             double dist1 = point_distance(point1, top1, point3, bottom1);             double dist2 = point_distance(point2, top2, point4, bottom2);             double direction1 = point_direction(point1, top1, point3, bottom1);             double direction2 = point_direction(point2, top2, point4, bottom2);             if (Math.abs(direction2 - direction1) > 180) {                if (direction2 < direction1) {                   direction2 = 360;                }else{                   direction1 = 360;                }             }             double repeat = (int) Math.ceil(length / 3.5D); //quality of the texturing            if (repeat <= 8)                repeat = 8; //need at least 1 draw call per image!            if (repeat > 32)                repeat = 32;                         int cellwidth = (int) Math.ceil(  length/repeat  ); //width of each image part of the floor            Graphics2D g2d = (Graphics2D)g;             double number = point2 - point1;             double changex = number / repeat;             double changey = (top2 - top1) / repeat;             double changedir = (direction2 - direction1) / repeat;             double changedist = (dist2 - dist1) / repeat;             double cellwidthintex = sprite_height/repeat;             for (int ii = 1; ii <= repeat+1; ii++) { //amount of draw calls per image (the more, the better quality)               int i = ii;                if (x >= newCamera.getX()) {                   i = (int) (repeat + 2 - ii);                }                double dx = point1 + (changex * i);                double dy = top1 + (changey * i);                double rx = dx;// - (cellwidth);               double ry = dy;                double dir = direction1 + (changedir * i);                draw_set_rotation(g2d, dir, rx, ry);                double dist = dist1 + (changedist * i);                int sy1 = (int) (cellwidthintex * (i - 1));                int sx1 = 0;                int sy2 = (int) (sy1 + cellwidthintex);                int sx2 = this.sprite_width;                g.drawImage(this.sprite_index, (int)dx, (int)dy, (int)dx + (int)dist, (int)dy + (int)cellwidth + 1, sx1, sy1, sx2, sy2, null);                draw_set_removerot(g2d, dir, rx, ry);             }

What the above code does, can be slightly explained from this picture:


If you need me to explain anything else, please ask

[orange451]

Any help would be greatly appreciated!

[Roquen]

My advice would be to render in scanline (horizontal) order.  Much simpler.

Games published by our own members! Check 'em out!

[orange451]

My advice would be to render in scanline (horizontal) order.  Much simpler.

The camera can turn, there would be no difference.

[Roquen]

I'm not understanding.  The camera does whatever it does and you still render in scanline order.

[EgonOlsen]

This really is a twisted and inefficient way of doing texture mapping. As Roquen said, you should consider to move to a scanline based approach instead. In addition, you can't take perspective into account when doing it this way.