static int Main(string[] args)
{
if (args.Length != 2)
{
Console.WriteLine($"ImageTint <image-path> <out>: Tints the image at <image-path> and saves it to <out>.");
return(1);
}
string inPath = args[0];
string outPath = args[1];
// This demo uses WindowState.Hidden to avoid popping up an unnecessary window to the user.
VeldridStartup.CreateWindowAndGraphicsDevice(
new WindowCreateInfo
{
WindowInitialState = WindowState.Hidden,
},
new GraphicsDeviceOptions(),
out Sdl2Window window,
out GraphicsDevice gd);
DisposeCollectorResourceFactory factory = new DisposeCollectorResourceFactory(gd.ResourceFactory);
ImageSharpTexture inputImage = new ImageSharpTexture(inPath, false);
Texture inputTexture = inputImage.CreateDeviceTexture(gd, factory);
TextureView view = factory.CreateTextureView(inputTexture);
Texture output = factory.CreateTexture(TextureDescription.Texture2D(
inputImage.Width,
inputImage.Height,
1,
1,
PixelFormat.R8_G8_B8_A8_UNorm,
TextureUsage.RenderTarget));
Framebuffer framebuffer = factory.CreateFramebuffer(new FramebufferDescription(null, output));
DeviceBuffer vertexBuffer = factory.CreateBuffer(new BufferDescription(64, BufferUsage.VertexBuffer));
Vector4[] quadVerts =
{
new Vector4(-1, 1, 0, 0),
new Vector4(1, 1, 1, 0),
new Vector4(-1, -1, 0, 1),
new Vector4(1, -1, 1, 1),
};
gd.UpdateBuffer(vertexBuffer, 0, quadVerts);
ShaderSetDescription shaderSet = new ShaderSetDescription(
new[]
{
new VertexLayoutDescription(
new VertexElementDescription("Position", VertexElementSemantic.Position, VertexElementFormat.Float2),
new VertexElementDescription("TextureCoordinates", VertexElementSemantic.TextureCoordinate, VertexElementFormat.Float2))
},
new[]
{
SampleApplication.LoadShader(factory, "TintShader", ShaderStages.Vertex, "VS"),
SampleApplication.LoadShader(factory, "TintShader", ShaderStages.Fragment, "FS")
});
ResourceLayout layout = factory.CreateResourceLayout(new ResourceLayoutDescription(
new ResourceLayoutElementDescription("Input", ResourceKind.TextureReadOnly, ShaderStages.Fragment),
new ResourceLayoutElementDescription("Sampler", ResourceKind.Sampler, ShaderStages.Fragment),
new ResourceLayoutElementDescription("Tint", ResourceKind.UniformBuffer, ShaderStages.Fragment)));
Pipeline pipeline = factory.CreateGraphicsPipeline(new GraphicsPipelineDescription(
BlendStateDescription.SingleOverrideBlend,
DepthStencilStateDescription.Disabled,
RasterizerStateDescription.Default,
PrimitiveTopology.TriangleStrip,
shaderSet,
layout,
framebuffer.OutputDescription));
DeviceBuffer tintInfoBuffer = factory.CreateBuffer(new BufferDescription(16, BufferUsage.UniformBuffer));
gd.UpdateBuffer(
tintInfoBuffer, 0,
new TintInfo(
new Vector3(1f, 0.2f, 0.1f), // Change this to modify the tint color.
0.25f));
ResourceSet resourceSet = factory.CreateResourceSet(
new ResourceSetDescription(layout, view, gd.PointSampler, tintInfoBuffer));
// RenderTarget textures are not CPU-visible, so to get our tinted image back, we need to first copy it into
// a "staging Texture", which is a Texture that is CPU-visible (it can be Mapped).
Texture stage = factory.CreateTexture(TextureDescription.Texture2D(
inputImage.Width,
inputImage.Height,
1,
1,
PixelFormat.R8_G8_B8_A8_UNorm,
TextureUsage.Staging));
CommandList cl = factory.CreateCommandList();
cl.Begin();
cl.SetFramebuffer(framebuffer);
cl.SetFullViewports();
cl.SetVertexBuffer(0, vertexBuffer);
cl.SetPipeline(pipeline);
cl.SetGraphicsResourceSet(0, resourceSet);
cl.Draw(4, 1, 0, 0);
cl.CopyTexture(
output, 0, 0, 0, 0, 0,
stage, 0, 0, 0, 0, 0,
stage.Width, stage.Height, 1, 1);
cl.End();
gd.SubmitCommands(cl);
gd.WaitForIdle();
// When a texture is mapped into a CPU-visible region, it is often not laid out linearly.
// Instead, it is laid out as a series of rows, which are all spaced out evenly by a "row pitch".
// This spacing is provided in MappedResource.RowPitch.
// It is also possible to obtain a "structured view" of a mapped data region, which is what is done below.
// With a structured view, you can read individual elements from the region.
// The code below simply iterates over the two-dimensional region and places each texel into a linear buffer.
// ImageSharp requires the pixel data be contained in a linear buffer.
MappedResourceView <Rgba32> map = gd.Map <Rgba32>(stage, MapMode.Read);
// Rgba32 is synonymous with PixelFormat.R8_G8_B8_A8_UNorm.
Rgba32[] pixelData = new Rgba32[stage.Width * stage.Height];
for (int y = 0; y < stage.Height; y++)
{
for (int x = 0; x < stage.Width; x++)
{
int index = (int)(y * stage.Width + x);
pixelData[index] = map[x, y];
}
}
gd.Unmap(stage); // Resources should be Unmapped when the region is no longer used.
Image <Rgba32> outputImage = Image.LoadPixelData(pixelData, (int)stage.Width, (int)stage.Height);
outputImage.Save(outPath);
factory.DisposeCollector.DisposeAll();
gd.Dispose();
window.Close();
return(0);
}