Files
SPIRV-Interpreter/example/main.zig
Kbz-8 c175224a01
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fixing example performance issues
2026-01-21 17:44:10 +01:00

95 lines
3.6 KiB
Zig

const std = @import("std");
const sdl3 = @import("sdl3");
const spv = @import("spv");
const shader_source = @embedFile("shader.spv");
const screen_width = 640;
const screen_height = 480;
pub fn main() !void {
{
//var gpa: std.heap.DebugAllocator(.{}) = .init;
//defer _ = gpa.deinit();
var gpa = std.heap.ArenaAllocator.init(std.heap.page_allocator);
defer gpa.deinit();
defer sdl3.shutdown();
const init_flags = sdl3.InitFlags{ .video = true };
try sdl3.init(init_flags);
defer sdl3.quit(init_flags);
const window = try sdl3.video.Window.init("Hello triangle", screen_width, screen_height, .{});
defer window.deinit();
const allocator = gpa.allocator();
var module = try spv.Module.init(allocator, @ptrCast(@alignCast(shader_source)), .{});
defer module.deinit(allocator);
const surface = try window.getSurface();
try surface.clear(.{ .r = 0.0, .g = 0.0, .b = 0.0, .a = 0.0 });
{
try surface.lock();
defer surface.unlock();
var pixel_map: [*]u32 = @as([*]u32, @ptrCast(@alignCast((surface.getPixels() orelse return).ptr)));
const margin_x = @divTrunc(screen_width, 3);
const margin_y = @divTrunc(screen_height, 3);
const top_y = margin_y;
const bottom_y = (screen_height - 1) - margin_y;
const center_x = @divTrunc(screen_width, 2);
const tri_h = bottom_y - top_y;
const max_half_w = @divTrunc(screen_width, 2) - margin_x;
var timer = try std.time.Timer.start();
defer {
const ns = timer.lap();
std.log.info("Took {d:.3}s to render", .{@as(f32, @floatFromInt(ns)) / std.time.ns_per_s});
}
for (top_y..bottom_y) |y| {
const t: f32 = @as(f32, @floatFromInt(y - top_y)) / @as(f32, @floatFromInt(tri_h));
const half_w: usize = @intFromFloat((t * @as(f32, @floatFromInt(max_half_w))) + 0.5);
const x0 = std.math.clamp(center_x - half_w, 0, screen_width - 1);
const x1 = std.math.clamp(center_x + half_w, 0, screen_width - 1);
for (x0..x1) |x| {
var rt = try spv.Runtime.init(allocator, &module);
defer rt.deinit(allocator);
var output: [4]f32 = undefined;
const entry = try rt.getEntryPointByName("main");
const color = try rt.getResultByName("color");
const dim = try rt.getResultByName("dim");
const pos = try rt.getResultByName("pos");
try rt.writeInput(f32, &.{ @floatFromInt(x1 - x0), @floatFromInt(bottom_y - top_y) }, dim);
try rt.writeInput(f32, &.{ @floatFromInt(x), @floatFromInt(y) }, pos);
try rt.callEntryPoint(allocator, entry);
try rt.readOutput(f32, output[0..], color);
const rgba = surface.mapRgba(
@truncate(@as(u32, @intFromFloat(output[0] * 255.0))),
@truncate(@as(u32, @intFromFloat(output[1] * 255.0))),
@truncate(@as(u32, @intFromFloat(output[2] * 255.0))),
@truncate(@as(u32, @intFromFloat(output[3] * 255.0))),
);
pixel_map[(y * surface.getWidth()) + x] = rgba.value;
}
}
}
try window.updateSurface();
std.Thread.sleep(2_000_000_000);
}
std.log.info("Successfully executed", .{});
}