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@@ -92,6 +92,54 @@ return {
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Subsequent compute shaders can be indirectly dispatched to perform extra processing on the
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visible objects. Finally, an indirect draw can be used to render them.
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]],
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+ example = {
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+ description = 'A compute shader that makes a texture grayscale.',
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+ code = [=[
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+ function lovr.load()
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+ shader = lovr.graphics.newShader([[
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+ layout(local_size_x = 8, local_size_y = 8) in;
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+ layout(set = 0, binding = 0, rgba8) uniform image2D image;
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+
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+ void lovrmain() {
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+ ivec2 size = imageSize(image);
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+ ivec2 pixel = ivec2(GlobalThreadID.xy);
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+
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+ if (pixel.x >= size.x || pixel.y >= size.y) {
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+ return;
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+ }
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+
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+ vec4 color = imageLoad(image, pixel);
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+ color.rgb = vec3(color.r * .4 + color.g * .5 + color.b * .1);
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+ imageStore(image, pixel, color);
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+ }
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+ ]])
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+
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+ texture = lovr.graphics.newTexture('image.png', {
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+ usage = { 'storage', 'sample', 'transfer' },
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+ linear = true -- srgb textures don't always support storage usage
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+ })
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+
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+ local tw, th = texture:getDimensions()
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+ local sx, sy = shader:getWorkgroupSize()
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+ local gx, gy = math.ceil(tw / sx), math.ceil(th / sy)
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+
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+ local computer = lovr.graphics.getPass('compute'),
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+ local transfer = lovr.graphics.getPass('transfer')
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+
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+ computer:setShader(shader)
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+ computer:send('image', texture)
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+ computer:compute(gx, gy)
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+ transfer:mipmap(texture)
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+
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+ lovr.graphics.submit(computer, transfer)
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+ end
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+
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+ function lovr.draw(pass)
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+ pass:setMaterial(texture)
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+ pass:plane(0, 1.7, -1)
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+ end
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+ ]=]
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+ },
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related = {
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'Pass:setShader',
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'Pass:send',
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bjorn