diff options
Diffstat (limited to 'src/render.zig')
| -rw-r--r-- | src/render.zig | 44 |
1 files changed, 40 insertions, 4 deletions
diff --git a/src/render.zig b/src/render.zig index 72121f2..6c54a00 100644 --- a/src/render.zig +++ b/src/render.zig @@ -316,9 +316,40 @@ pub fn Renderer(PlaneWidth: f32, PlaneHeight: f32) type { } var previous_layer_height: f32 = 0; - var previous_highest_drawn:f32 = highest_drawn; + var previous_highest_drawn: f32 = highest_drawn; for (cell.lower_layers.constSlice()) |layer| { - if (hitDistLocalCoords(ray0_x, ray0_y, ray1_x, ray1_y, layer.vertices.constSlice())) |hit| { + const should_try_to_draw_layer = switch (layer.polygon) { + .square => hit: { + // we have to compute texture_frac by hand. + var texfrac : f32 = undefined; + // Using the notation in the below diagram, + // we want face_i to have [0.25i, 0.25(i+1)] + // of the texture. + + // <---2--- + // | ^ + // 3 | + // | 1 + // v | + // ---0---> + + if (hit_horizontal) { + // a horizontal hit means we take the horizontal coordinate + texfrac = std.math.modf(distance * cosra + ppos_x).fpart / 4; + // we're either 0 or 2, if sinra < 0 then we're 2 + if (sinra < 0) texfrac = 0.50 + (0.25 - texfrac); + } else { + // a vertical hit means we take the vertical coordinate + texfrac = std.math.modf(distance * sinra + ppos_y).fpart / 4; + // we're either 1 or 3, if cosra < 0 then we're 1 + if (cosra < 0) texfrac += 0.25 else texfrac = 0.75 + (0.25 - texfrac); + } + + break :hit LocalCoordHit{ .local_dist = 0, .texture_frac = texfrac }; + }, + .vertices => |vs| hitDistLocalCoords(ray0_x, ray0_y, ray1_x, ray1_y, vs.constSlice()), + }; + if (should_try_to_draw_layer) |hit| { // TODO: Correct for fisheye? Is this what FOV_SCALE does? const adj_distance = distance + hit.local_dist * FOV_SCALE; @@ -397,14 +428,19 @@ pub fn Renderer(PlaneWidth: f32, PlaneHeight: f32) type { 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; + if (sx < 0 or sy < 0 or @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 should_be_drawn = switch (layer.polygon) { + .square => true, + .vertices => |vs| pointInPoly(rx, ry, vs.constSlice()), + }; + + if (should_be_drawn) { const px = @floatToInt(c_uint, constants.TextureDim * rx); const py = @floatToInt(c_uint, constants.TextureDim * ry); pixels[pix_index] = surfaces_image.getPixel(.{ .x = toff + px, .y = py }); |