diff options
Diffstat (limited to 'src/render.zig')
| -rw-r--r-- | src/render.zig | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/src/render.zig b/src/render.zig index 1cec3a6..647e7f8 100644 --- a/src/render.zig +++ b/src/render.zig @@ -289,9 +289,7 @@ pub fn Renderer(PlaneWidth: f32, PlaneHeight: f32) type { }) { const cell = map.lookup(ipos_x, ipos_y); - // Are we drawing vertical surfaces? - - // TODO: not quite right, ``anything vertical'' not just ``anything'' + // Are we drawing this cell? if (cell.lower_layers.len > 0) { var ray0_x: f32 = undefined; var ray0_y: f32 = undefined; @@ -342,14 +340,16 @@ pub fn Renderer(PlaneWidth: f32, PlaneHeight: f32) type { const td = @floatToInt(c_uint, constants.TextureDim); const t_lower_off = layer.vertical_texture * td; - // Note the bizarre rounding we have to do to avoid artifacts + // Note the rounding we have to do to avoid + // artifacts const constrained_top = std.math.floor(std.math.min(top_of_floor, lowest_drawn)); const proj_height = (layer.height - previous_layer_height) * nominal_length; // if we're above the layer that set the // highest_drawn values, we can draw down // into it (for walls over floors) - const constrained_bottom = std.math.max(if (highest_drawn_same_square) previous_highest_drawn else highest_drawn, top_of_floor - proj_height); + const alternate_bottom = if (highest_drawn_same_square) previous_highest_drawn else highest_drawn; + const constrained_bottom = std.math.max(alternate_bottom, top_of_floor - proj_height); const stop_top = std.math.max(0, PlaneHeight - constrained_bottom); const stop = @floatToInt(usize, PlaneWidth * stop_top) + col; const pix_y = @floatToInt(usize, std.math.ceil(std.math.max(PlaneHeight - constrained_top - 1, 0))); @@ -377,13 +377,16 @@ pub fn Renderer(PlaneWidth: f32, PlaneHeight: f32) type { // than it). If the wall is shorter then the back edge // is at most the horizon. const next_top = PlaneHeight / 2 + PlaneDist * (layer.height - pheight) / next_distance; + if (next_top > highest_drawn) { highest_drawn_same_square = true; const toff = layer.horizontal_texture * @floatToInt(c_uint, constants.TextureDim); var top = std.math.ceil(std.math.min(std.math.min(next_top, lowest_drawn), PlaneHeight / 2 - 1)); - const thresh = highest_drawn; + // TODO: Literal corner case. Clip the bottom of a wall to see this + const thresh = if (highest_drawn_same_square) previous_highest_drawn else highest_drawn; + // const thresh = highest_drawn; const itop = @floatToInt(usize, top); const ptop = @floatToInt(usize, PlaneHeight) - itop; @@ -392,10 +395,19 @@ pub fn Renderer(PlaneWidth: f32, PlaneHeight: f32) type { top -= 1; pix_index += @floatToInt(usize, PlaneWidth); }) { + // where would the source of this pixel be? const row_dist = (pheight - layer.height) * PlaneDist / (PlaneHeight / 2 - top); - // draw the correct pixel - const rx = std.math.modf(ppos_x + row_dist * cosra).fpart; - const ry = std.math.modf(ppos_y + row_dist * sinra).fpart; + const sx = ppos_x + row_dist * cosra; + const sy = ppos_y + row_dist * sinra; + + // only proceed if it's in the current square + if (@floatToInt(i32, sx) != ipos_x or @floatToInt(i32, sy) != ipos_y) continue; + + // where does it land in the square? + const rx = std.math.modf(sx).fpart; + const ry = std.math.modf(sy).fpart; + + // is it in the polygon? if (pointInPoly(rx, ry, layer.vertices.constSlice())) { const px = @floatToInt(c_uint, constants.TextureDim * rx); const py = @floatToInt(c_uint, constants.TextureDim * ry); @@ -403,7 +415,7 @@ pub fn Renderer(PlaneWidth: f32, PlaneHeight: f32) type { if (top > highest_drawn) { highest_drawn = top; } - if (layer.height > 0) self.z_buffer[pix_index] = row_dist; + self.z_buffer[pix_index] = row_dist; } } } |