diff options
Diffstat (limited to 'src/player.zig')
| -rw-r--r-- | src/player.zig | 538 |
1 files changed, 64 insertions, 474 deletions
diff --git a/src/player.zig b/src/player.zig index 7a94b7b..258b924 100644 --- a/src/player.zig +++ b/src/player.zig @@ -26,490 +26,80 @@ const Colour = @import("sfml").graphics.Color; const level = @import("level.zig"); const constants = @import("constants.zig"); -fn playerDistComp(pos: [2]f32, lhs: level.Object, rhs: level.Object) bool { - const lx = lhs.pos_x - pos[0]; - const ly = lhs.pos_y - pos[1]; - const rx = rhs.pos_x - pos[0]; - const ry = rhs.pos_y - pos[1]; +pub const Player = struct { + pos_x: f32, + pos_y: f32, + ang: f32, + vel_x: f32 = 0, + vel_y: f32 = 0, + acc_x: f32 = 0, + acc_y: f32 = 0, + height: f32 = 2.0 * (1.8 / 2.5), // TODO + anim_step: f32 = 0, - return (lx * lx + ly * ly > rx * rx + ry * ry); -} + // standing still at the given location, looking in direction ang + pub fn new(pos_x: f32, pos_y: f32, ang: f32) @This() { + return Player{ + .pos_x = pos_x, + .pos_y = pos_y, + .ang = ang, + }; + } -fn fasterColourBlend(onto: Colour, from: Colour) Colour { - const af: u16 = from.a; - const of: u16 = onto.a; + pub fn tick(self: *Player, map: level.Map) void { + const dt = 1 / 30.0; + const v_min = 0.8; + const v_decay = 1 / 1.25; - const ablend: u16 = @divTrunc(of * (255 - af), 255); - const na: u16 = af + ablend; - if (na == 0) return Colour.Black; + var next_x = self.pos_x + self.vel_x * dt; + var next_y = self.pos_y + self.vel_y * dt; - const rf: u16 = from.r; - const ro: u16 = onto.r; - const gf: u16 = from.g; - const go: u16 = onto.g; - const bf: u16 = from.b; - const bo: u16 = onto.b; + // Collision detection + const min_dist: f32 = 0.1; + const fx = std.math.floor(self.pos_x); + const fy = std.math.floor(self.pos_y); + const ix = @floatToInt(i32, fx); + const iy = @floatToInt(i32, fy); + const nix = @floatToInt(i32, std.math.floor(next_x + if (self.vel_x > 0) min_dist else -min_dist)); + const niy = @floatToInt(i32, std.math.floor(next_y + if (self.vel_y > 0) min_dist else -min_dist)); - // The most accurate i've found is - const nr = @divTrunc(ro * ablend + rf * af, na); - const ng = @divTrunc(go * ablend + gf * af, na); - const nb = @divTrunc(bo * ablend + bf * af, na); - - // These computations are incorrect, but faster - // const nr = (af * rf + (255 - af) * ro) / 255; - // const ng = (af * gf + (255 - af) * go) / 255; - // const nb = (af * bf + (255 - af) * bo) / 255; - - return Colour{ - .a = @intCast(u8, na), - .r = @intCast(u8, nr), - .g = @intCast(u8, ng), - .b = @intCast(u8, nb), - }; -} - -pub fn Player(PlaneWidth: f32, PlaneHeight: f32) type { - const FOV: f32 = std.math.pi / 3.0; - const PlanePixels = PlaneWidth * PlaneHeight; - // given the desired width of the image, how far away must - // the projection plane be from the camera? - const FOV_SCALE = 2 * std.math.tan(FOV / 2); - const PlaneDist = PlaneWidth / FOV_SCALE; - - return struct { - pos_x: f32, - pos_y: f32, - ang: f32, - vel_x: f32 = 0, - vel_y: f32 = 0, - acc_x: f32 = 0, - acc_y: f32 = 0, - height: f32 = 2.0 * (1.8 / 2.5), // TODO - z_buffer: [PlanePixels]f32, - anim_step: f32 = 0, - - // standing still at the given location, looking in direction ang - pub fn new(pos_x: f32, pos_y: f32, ang: f32) @This() { - return Player(PlaneWidth, PlaneHeight){ - .pos_x = pos_x, - .pos_y = pos_y, - .ang = ang, - .z_buffer = [_]f32{std.math.inf(f32)} ** PlanePixels, - }; - } - - pub fn tick(self: *@This(), map: level.Map) void { - const dt = 1 / 30.0; - const v_min = 0.8; - const v_decay = 1 / 1.25; - - var next_x = self.pos_x + self.vel_x * dt; - var next_y = self.pos_y + self.vel_y * dt; - - // Collision detection - const min_dist: f32 = 0.1; - const fx = std.math.floor(self.pos_x); - const fy = std.math.floor(self.pos_y); - const ix = @floatToInt(i32, fx); - const iy = @floatToInt(i32, fy); - const nix = @floatToInt(i32, std.math.floor(next_x + if (self.vel_x > 0) min_dist else -min_dist)); - const niy = @floatToInt(i32, std.math.floor(next_y + if (self.vel_y > 0) min_dist else -min_dist)); - - if (!map.inBounds(nix, iy) or - blk: { - const cell = map.lookup(nix, iy); - if (cell.floor_height > 0) break :blk true; - if (cell.ceiling_height < self.height) break :blk true; - break :blk false; - }) { - next_x = fx + if (self.vel_x > 0) 1 - min_dist else min_dist; - self.vel_x = 0; - self.acc_x = 0; - } - - if (!map.inBounds(ix, niy) or map.lookup(ix, niy).floor_height > 0) { - next_y = fy + if (self.vel_y > 0) 1 - min_dist else min_dist; - self.vel_y = 0; - self.acc_y = 0; - } - - // Update position - self.pos_x = next_x; - self.pos_y = next_y; - - // Update velocity - self.vel_x += self.acc_x * dt; - self.vel_y += self.acc_y * dt; - - const vd = v_decay * std.math.sqrt(self.vel_x * self.vel_x + self.vel_y * self.vel_y); - if (vd < v_min) { - self.vel_x = 0; - self.vel_y = 0; - } else { - // If we're moving update our animation state - self.anim_step += 1; - self.height -= std.math.sin(self.anim_step / 10 * std.math.pi) * 0.015; - - self.vel_x *= v_decay; - self.vel_y *= v_decay; - } + if (!map.inBounds(nix, iy) or + blk: { + const cell = map.lookup(nix, iy); + if (cell.floor_height > 0) break :blk true; + if (cell.ceiling_height < self.height) break :blk true; + break :blk false; + }) { + next_x = fx + if (self.vel_x > 0) 1 - min_dist else min_dist; + self.vel_x = 0; + self.acc_x = 0; } - pub fn renderWorld( - self: *@This(), - window: RenderWindow, - objects_image: Image, - walls_image: Image, - surfaces_image: Image, - rendered_surfaces_texture: Texture, - rendered_surfaces_sprite: Sprite, - map: level.Map, - ) !void { - // Fist reset the z_buffer - var i: usize = 0; - while (i < self.z_buffer.len) : (i += 1) { - self.z_buffer[i] = std.math.inf(f32); - } - - var pixels = [_]Colour{Colour.Transparent} ** (PlaneWidth * PlaneHeight); - - // Draw all vertical and horizontal surfaces, and populate the z-buffer - self.renderCells(walls_image, surfaces_image, map, &pixels); - - // use the z_buffer to render sprites - self.renderObjects(objects_image, map, &pixels); - - try rendered_surfaces_texture.updateFromPixels(&pixels, null); - window.draw(rendered_surfaces_sprite, null); - } - - fn renderObjects( - self: @This(), - objects_image: Image, - map: level.Map, - pixels: []Colour, - ) void { - std.sort.sort(level.Object, map.objects.items, - // Wow, context with an arbitrary type! No macros, just - // Zig all the way down! - [2]f32{ self.pos_x, self.pos_y }, playerDistComp); - - const self_cos = std.math.cos(self.ang); - const self_sin = std.math.sin(self.ang); - - for (map.objects.items) |obj| { - const ox = obj.pos_x - self.pos_x; - const oy = obj.pos_y - self.pos_y; - - // We compute the two coordinates of rotating by -self.ang, the - // first of which gives the perpendicular distance to the plane - // of projection, and the second of which gives the - // (unprojected) centre of the object. - const perp_distance = self_cos * ox + self_sin * oy; - const centre = self_sin * ox - self_cos * oy; - - // NOTE: in the below we have applied the magic scaling factor - // of FOV_SCALE. I don't understand how this compensates for the - // linear interpolation incorrectness we do elsewhere, but - // somehow it scales the *correct* values we compute above into - // whatever agrees with the wall and floor rendering voodoo. - - // This quantity is independent of FOV_SCALE because it enters - // both via centre and perp_distance - const proj_centre = PlaneWidth / 2 + PlaneDist * centre / perp_distance; - - // Here's the magic adjustment - const scaled_perp_distance = FOV_SCALE * perp_distance; - const width = PlaneDist * obj.width / scaled_perp_distance; - const left = proj_centre - width / 2; - - // TODO: prune before this? - if (left + width < 0 or left >= PlaneWidth) continue; - - const height = PlaneDist * obj.height / scaled_perp_distance; - const top = PlaneHeight / 2 + PlaneDist * (obj.height - self.height + obj.pos_z) / scaled_perp_distance; - - // TODO: likewise? - if (top < 0 or top - height >= PlaneHeight) continue; - - // Something is on the screen, let's draw it! - const start = std.math.max(0, left); - const end = @floatToInt(usize, std.math.min(left + width, PlaneWidth - 1)); - - const inv_height = 1 / height; - - var tex_frac: f32 = std.math.clamp((start - left) / width, 0, 1); - var col: usize = @floatToInt(usize, start); - const tex_frac_step = 1 / width; - while (col < end) : ({ - col += 1; - tex_frac += tex_frac_step; - }) { - var bottom = std.math.min(top, PlaneHeight); - var pix_y = @floatToInt(usize, std.math.ceil(std.math.max(PlaneHeight - bottom - 1, 0))); - var texel_y = (top - bottom) / height; - while (pix_y < PlaneHeight and bottom >= top - height) : ({ - bottom -= 1; - pix_y += 1; - texel_y += inv_height; - }) { - const index = col * @floatToInt(usize, PlaneHeight) + @floatToInt(usize, bottom); - if (self.z_buffer[index] > scaled_perp_distance) { - const tx = @floatToInt(c_uint, tex_frac * (constants.TextureDim - 1)); - const toff = obj.texture * @floatToInt(c_uint, constants.TextureDim); - const ty = @floatToInt(c_uint, texel_y * (constants.TextureDim - 1)); - const texel = objects_image.getPixel(.{ .x = toff + tx, .y = ty }); - const pix_index = @floatToInt(usize, PlaneWidth) * pix_y + col; - // TODO: Decide whether being accurate is as important as being fast - pixels[pix_index] = fasterColourBlend(pixels[pix_index], texel); - } - } - } - } + if (!map.inBounds(ix, niy) or map.lookup(ix, niy).floor_height > 0) { + next_y = fy + if (self.vel_y > 0) 1 - min_dist else min_dist; + self.vel_y = 0; + self.acc_y = 0; } - fn renderCells( - self: *@This(), - walls_image: Image, - surfaces_image: Image, - map: level.Map, - pixels: []Colour, - ) void { - // This is a TERRIBLE hack: for whatever reason *linearly* - // interpolating on the direction vectors gives - // perspective-correct-seeming walls! - const cos_first = std.math.cos(self.ang + 0.5 * FOV); - const cos_last = std.math.cos(self.ang - 0.5 * FOV); - const sin_first = std.math.sin(self.ang + 0.5 * FOV); - const sin_last = std.math.sin(self.ang - 0.5 * FOV); - - const cos_step = (cos_last - cos_first) / PlaneWidth; - const sin_step = (sin_last - sin_first) / PlaneWidth; - - var col: u16 = 0; - var cosra = cos_first; - var sinra = sin_first; - while (col < PlaneWidth) : ({ - col += 1; - cosra += cos_step; - sinra += sin_step; - }) { - // Observe that sqrt(1+tan^2) = abs(1/cos) sqrt(cos^2+sin^2) = - // abs(1/cos). Similarly so for cot, hence we obtain the - // following lengths for the hypotenuses assuming that x - // (respectively y) are unit length and the angle is ra. This - // for whatever reasons still works when we linearly interpolate - // on cos and sin! - const dy_for_x_step = std.math.fabs(1 / cosra); - const dx_for_y_step = std.math.fabs(1 / sinra); - - var step_x: i32 = -1; - var step_y: i32 = -1; - - var dist_x: f32 = undefined; - var dist_y: f32 = undefined; - - var ipos_x: i32 = @floatToInt(i32, std.math.floor(self.pos_x)); - var ipos_y: i32 = @floatToInt(i32, std.math.floor(self.pos_y)); - - // looking right - if (cosra >= 0) { - step_x = 1; - // assuming unit size grid cells - dist_y = (@intToFloat(f32, ipos_x) + 1 - self.pos_x) * dy_for_x_step; - } else { - dist_y = (self.pos_x - @intToFloat(f32, ipos_x)) * dy_for_x_step; - } - - if (sinra >= 0) { - step_y = 1; - dist_x = (@intToFloat(f32, ipos_y) + 1 - self.pos_y) * dx_for_y_step; - } else { - dist_x = (self.pos_y - @intToFloat(f32, ipos_y)) * dx_for_y_step; - } - - var top_of_floor: f32 = undefined; - var bottom_of_ceiling: f32 = undefined; - var distance: f32 = 0; - var still_drawing = true; - var highest_drawn: f32 = 0; - var lowest_drawn: f32 = PlaneHeight - 1; - var horizontal_hit: bool = undefined; - while (still_drawing and map.inBounds(ipos_x, ipos_y)) : ({ - // Find the next cell on our path - if (dist_y < dist_x) { - horizontal_hit = false; - distance = dist_y; - dist_y += dy_for_x_step; - ipos_x += step_x; - } else { - horizontal_hit = true; - distance = dist_x; - dist_x += dx_for_y_step; - ipos_y += step_y; - } - }) { - const cell = map.lookup(ipos_x, ipos_y); - - // Are we drawing vertical surfaces? - if (cell.floor_height > 0 or cell.draw_down) { - // project the top of the bottom and the bottom of the top - top_of_floor = PlaneHeight / 2 + PlaneDist * (cell.floor_height - self.height) / distance; - bottom_of_ceiling = PlaneHeight / 2 + PlaneDist * (cell.ceiling_height - self.height) / distance; - - const draw_lower = top_of_floor > highest_drawn; - const draw_upper = cell.draw_down and bottom_of_ceiling < lowest_drawn; - - // Are we able to see any vertical faces? - if (draw_upper or draw_lower) { - // we need the distance to calculate the fractional - // part of the relevant coordinate for texture - // mapping of the walls - const hit_coordinate = if (horizontal_hit) distance * cosra + self.pos_x else distance * sinra + self.pos_y; - var texfrac = std.math.modf(hit_coordinate).fpart; - - // we also want to be sure that we're consistently orienting - // textures, in this case clockwise - if ((horizontal_hit and sinra < 0) or (!horizontal_hit and cosra > 0)) texfrac = 1 - texfrac; - const texstrip = @floatToInt(c_uint, (constants.TextureDim - 1) * texfrac); - - // height of a unit-height wall at this distance - const nominal_length = PlaneDist / distance; - const inv_nom_len = distance / PlaneDist; - // used for texel indexing - - const td = @floatToInt(c_uint, constants.TextureDim); - if (draw_lower) { - // which texture index? - const t_lower_off = cell.lower_texture * td; - // Note the bizarre rounding we have to do to avoid artifacts - const constrained_top = std.math.min(std.math.floor(top_of_floor), std.math.ceil(lowest_drawn)); - const stop = @floatToInt(i32, highest_drawn); - var zb_y = @floatToInt(i32, constrained_top); - var pix_y = @floatToInt(usize, std.math.ceil(std.math.max(PlaneHeight - constrained_top, 0))); - var texel_y = (top_of_floor - constrained_top) / nominal_length; - - // now we have what we need to draw the face, - // and update the z-buffer - while (zb_y > stop) : ({ - zb_y -= 1; - pix_y += 1; - texel_y += inv_nom_len; - }) { - const ty = @floatToInt(c_uint, std.math.modf(texel_y).fpart * constants.TextureDim); - const texel = walls_image.getPixel(.{ .x = t_lower_off + texstrip, .y = ty }); - - const pix_index = pix_y * @floatToInt(usize, PlaneWidth) + col; - pixels[pix_index] = texel; - - const index = @intCast(usize, col * @floatToInt(i32, PlaneHeight) + zb_y); - self.z_buffer[index] = distance; - } - highest_drawn = top_of_floor; - } - - if (draw_upper) { - const proj_default_end = PlaneHeight / 2 + PlaneDist * (level.Cell.DEFAULT_HEIGHT - self.height) / distance; - const stop = @floatToInt(i32, std.math.min(lowest_drawn, proj_default_end)); - const t_upper_off = cell.upper_texture * td; - const constrained_bottom = std.math.max(bottom_of_ceiling, highest_drawn); - var zb_y = @floatToInt(i32, constrained_bottom); - var pix_y = @floatToInt(usize, std.math.ceil(std.math.max(PlaneHeight - constrained_bottom - 1, 0))); - var texel_y: f32 = 0; - while (zb_y < stop) : ({ - zb_y += 1; - pix_y -= 1; - texel_y += inv_nom_len; - }) { - const ty = @floatToInt(c_uint, (1 - std.math.modf(texel_y).fpart) * (constants.TextureDim - 1)); - const texel = walls_image.getPixel(.{ .x = t_upper_off + texstrip, .y = ty }); - - const pix_index = pix_y * @floatToInt(usize, PlaneWidth) + col; - pixels[pix_index] = texel; - - const index = @intCast(usize, col * @floatToInt(i32, PlaneHeight) + zb_y); - self.z_buffer[index] = distance; - } - lowest_drawn = bottom_of_ceiling; - } - } - } - - // do we potentially draw floor for this cell? - if (highest_drawn < PlaneHeight / 2 or (cell.draw_down and lowest_drawn > PlaneHeight / 2)) { - if (dist_y < dist_x) { - distance = dist_y; - } else { - distance = dist_x; - } - - // Note: next_top can never exceed PlaneHeight / 2 in - // the body of the next block. If the wall is taller - // than us the back edge is lower than the front one so - // this check will fail as we just drew it (or higher - // than it). If the wall is shorter then the back edge - // is at most the horizon. Similarly so for next_bottom - const next_top = PlaneHeight / 2 + PlaneDist * (cell.floor_height - self.height) / distance; - const next_bottom = PlaneHeight / 2 + PlaneDist * (cell.ceiling_height - self.height) / distance; - - // draw floor? - if (next_top > highest_drawn) { - top_of_floor = std.math.floor(highest_drawn); - const thresh = std.math.min(std.math.min(next_top, lowest_drawn), PlaneHeight / 2) - 1; - while (top_of_floor <= thresh) : (top_of_floor += 1) { - const row_dist = (self.height - cell.floor_height) * PlaneDist / (PlaneHeight / 2 - top_of_floor); - const ptop = @floatToInt(usize, top_of_floor); - const itop = @floatToInt(usize, PlaneHeight) - ptop - 1; - - // draw the correct pixel - const sx = std.math.modf(self.pos_x + row_dist * cosra); - const sy = std.math.modf(self.pos_y + row_dist * sinra); - const toff = cell.floor_texture * @floatToInt(c_uint, constants.TextureDim); - const px = @floatToInt(c_uint, constants.TextureDim * std.math.fabs(sx.fpart)); - const py = @floatToInt(c_uint, constants.TextureDim * std.math.fabs(sy.fpart)); - const val = surfaces_image.getPixel(.{ .x = toff + px, .y = py }); - pixels[itop * @floatToInt(usize, PlaneWidth) + col] = val; - - // record in the z_buffer only if we're above the floor! - if (cell.floor_height > 0) { - const index = col * @floatToInt(usize, PlaneHeight) + ptop; - self.z_buffer[index] = row_dist; - } - } - highest_drawn = next_top; - } + // Update position + self.pos_x = next_x; + self.pos_y = next_y; - // draw ceiling? - if (cell.draw_down and next_bottom < lowest_drawn) { - bottom_of_ceiling = std.math.ceil(lowest_drawn); - const thresh = std.math.max(std.math.max(next_bottom, highest_drawn), PlaneHeight / 2) - 1; - while (bottom_of_ceiling > thresh) : (bottom_of_ceiling -= 1) { - const row_dist = (cell.ceiling_height - self.height) * PlaneDist / (bottom_of_ceiling - PlaneHeight / 2); - const ptop = @floatToInt(usize, bottom_of_ceiling); - const itop = @floatToInt(usize, PlaneHeight) - ptop; + // Update velocity + self.vel_x += self.acc_x * dt; + self.vel_y += self.acc_y * dt; - const sx = std.math.modf(self.pos_x + row_dist * cosra); - const sy = std.math.modf(self.pos_y + row_dist * sinra); - const toff = cell.ceiling_texture * @floatToInt(c_uint, constants.TextureDim); - const px = @floatToInt(c_uint, constants.TextureDim * std.math.fabs(sx.fpart)); - const py = @floatToInt(c_uint, constants.TextureDim * std.math.fabs(sy.fpart)); - const val = surfaces_image.getPixel(.{ .x = toff + px, .y = py }); - pixels[itop * @floatToInt(usize, PlaneWidth) + col] = val; + const vd = v_decay * std.math.sqrt(self.vel_x * self.vel_x + self.vel_y * self.vel_y); + if (vd < v_min) { + self.vel_x = 0; + self.vel_y = 0; + } else { + // If we're moving update our animation state + self.anim_step += 1; + self.height -= std.math.sin(self.anim_step / 10 * std.math.pi) * 0.015; - if (cell.draw_down) { - const index = col * @floatToInt(usize, PlaneHeight) + ptop; - self.z_buffer[index] = row_dist; - } - } - lowest_drawn = next_bottom; - } - } - } - // Have we filled this column? - if (top_of_floor > lowest_drawn or bottom_of_ceiling < highest_drawn) { - still_drawing = false; - } - } + self.vel_x *= v_decay; + self.vel_y *= v_decay; } - }; -} + } +}; |