[ren.quad] quad_renderer can now be configured to use alpha clipping,…

… and also its clear colour can be set at creation time

include/tz/ren/quad.hpp

@@ -14,9 +14,25 @@ namespace tz::ren
 	using quad_handle = tz::handle<detail::quad_t>;
 	using quad_renderer_handle = tz::handle<detail::quadren_t>;
 
-	struct quad_renderer_info
+	enum quad_renderer_flag
+	{
+		alpha_clipping = 0b0001,
+	};
+
+	constexpr quad_renderer_flag operator|(quad_renderer_flag lhs, quad_renderer_flag rhs)
+	{
+		return static_cast<quad_renderer_flag>(static_cast<int>(lhs) | static_cast<int>(rhs));
+	}
+
+	constexpr bool operator&(quad_renderer_flag lhs, quad_renderer_flag& rhs)
 	{
+		return static_cast<int>(lhs) & static_cast<int>(rhs);
+	}
 
+	struct quad_renderer_info
+	{
+		tz::v4f clear_colour = {0.0f, 0.0f, 0.0f, 1.0f};
+		quad_renderer_flag flags = static_cast<quad_renderer_flag>(0);
 	};
 
 	std::expected<quad_renderer_handle, tz::error_code> create_quad_renderer(quad_renderer_info info);

src/tz/ren/quad.cpp

@@ -23,6 +23,7 @@ namespace tz::ren
 		quad_renderer_info info = {};
 		tz::gpu::resource_handle data_buffer = tz::nullhand;
 		tz::gpu::resource_handle camera_buffer = tz::nullhand;
+		tz::gpu::resource_handle settings_buffer = tz::nullhand;
 		tz::gpu::pass_handle main_pass = tz::nullhand;
 		tz::gpu::graph_handle graph = tz::nullhand;
 		std::vector<quad_internal_data> internals = {};
@@ -75,19 +76,28 @@ namespace tz::ren
 			.name = "Quad Renderer Camera Buffer"
 		}));
 
+		auto settings_val = static_cast<std::uint32_t>(info.flags);
+		ren.settings_buffer = tz_must(tz::gpu::create_buffer
+		({
+			.data = std::as_bytes(std::span<const std::uint32_t>(&settings_val, 1)),
+			.name = "Quad Renderer Settings Buffer"
+		}));
+
 		tz::gpu::resource_handle colour_targets[] = 
 		{
 			tz::gpu::window_resource
 		};
 		tz::gpu::resource_handle resources[] =
 		{
 			ren.data_buffer,
-			ren.camera_buffer
+			ren.camera_buffer,
+			ren.settings_buffer
 		};
 		auto maybe_pass = tz::gpu::create_pass
 		({
 			.graphics = 
 			{
+				.clear_colour = info.clear_colour,
 				.colour_targets = colour_targets,
 				.flags = tz::gpu::graphics_flag::no_depth_test
 			},

src/tz/ren/quad.fragment.tzsl

@@ -3,6 +3,7 @@ shader(type = fragment);
 input(id = 0) vec3 tint;
 input(id = 1) vec2 uv;
 input(id = 2, flat) uint texture_id;
+input(id = 3, flat) uint alpha_clipping;
 output(id = 0) vec4 colour;
 
 void main()
@@ -11,7 +12,12 @@ void main()
 	vec3 frag_colour = tint;
 	if(texture_id != -1)
 	{
-		frag_colour *= sample(texture_id, uv).xyz;
+		vec4 texcol = sample(texture_id, uv);
+		if(alpha_clipping == 1 && texcol.a < 0.05f)
+		{
+			discard;
+		}
+		frag_colour *= texcol.xyz;
 	}
 
 	colour = vec4(frag_colour, 1.0f);

src/tz/ren/quad.vertex.tzsl

@@ -17,9 +17,15 @@ resource(id = 1) const buffer camera
 	mat4 projection;	
 };
 
+resource(id = 2) const buffer settings
+{
+	uint value;
+};
+
 output(id = 0) vec3 out::tint;
 output(id = 1) vec2 out::uv;
 output(id = 2) uint out::texture_id;
+output(id = 3) uint out::alpha_clipping;
 
 vec2 quad_positions[6] = vec2[](
 	vec2(1.0, -1.0), vec2(1.0, 1.0), vec2(-1.0, -1.0),
@@ -41,4 +47,5 @@ void main()
 	out::tint = vec3(cur_quad.colour);
 	out::uv = quad_texcoords[in::vertex_id % 6];
 	out::texture_id = cur_quad.texture_id;
+	out::alpha_clipping = settings.value & 0x01;
 }