77 lines
2.4 KiB
Zig
77 lines
2.4 KiB
Zig
const std = @import("std");
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const gpu = @import("gpu");
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const GpuDevice = gpu.GpuDevice;
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const GpuArena = gpu.GpuArena;
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const GpuBuffer = gpu.GpuBuffer;
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const GpuRender = gpu.GpuRender;
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const GpuTexture = gpu.GpuTexture;
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const GpuTextureView = gpu.GpuTextureView;
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const width: u32 = 512;
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const height: u32 = 512;
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pub fn main(init: std.process.Init) !void {
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const allocator = init.gpa;
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// 1. Open GPU Device
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const device = try GpuDevice.init(.{});
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defer device.deinit();
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// 2. Init VRAM Arena
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var grena = GpuArena.init(allocator, device);
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defer grena.deinit();
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const gloc = grena.gpuAllocator();
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// 3. Load Render Pipeline
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const circle_rp = try GpuRender.init(
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device, // Change to gloc + track them
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@embedFile("shaders/circle.wgsl"),
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.{ .bindings = &.{}, .texture_format = .RGBA8Unorm, .topology = .TriangleStrip },
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);
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defer circle_rp.deinit();
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// 4. Create VRAM texture to render into
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const texture = try GpuTexture.init(gloc, .{
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.format = .RGBA8Unorm,
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.size = .{ .width = width, .height = height, .depthOrArrayLayers = 1 },
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.usage = .initMany(&.{ .RenderAttachment, .CopySrc }),
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});
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defer texture.deinit();
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// 5. Create a view from texture
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const view = try GpuTextureView.init(gloc, texture, .{});
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defer view.deinit();
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// 6. Run the rendering pipeline
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try circle_rp.draw(gloc, view, 4, .{});
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// 7. Load Texture into GpuBuffer
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const cpu_staging_cpu = try texture.buffCopy(gloc);
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defer cpu_staging_cpu.deinit();
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// 8. Read GpuBuffer to CPU
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const pixels = try cpu_staging_cpu.read(allocator, u8);
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defer allocator.free(pixels);
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// 9. Write a simple ppm image
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try savePpm(init.io, "circle.ppm", width, height, pixels);
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std.debug.print("Successfully rendered circle to circle.ppm!\n", .{});
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}
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fn savePpm(io: std.Io, filename: []const u8, w: u32, h: u32, rgba_pixels: []const u8) !void {
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const file = try std.Io.Dir.cwd().createFile(io, filename, .{});
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defer file.close(io);
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var buf: [255]u8 = undefined;
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var writer = file.writer(io, &buf);
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// PPM Header: P6 format means raw RGB bytes
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try writer.interface.print("P6\n{d} {d}\n255\n", .{ w, h });
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// Strip Alpha channel when writing out to standard RGB PPM format
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var i: usize = 0;
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while (i < rgba_pixels.len) : (i += 4) {
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try writer.interface.writeAll(rgba_pixels[i .. i + 3]);
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}
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}
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