[imgui] imgui backend WIP

CMakeLists.txt

@@ -50,6 +50,8 @@ topaz_add_library(
 		src/tz/io/image.cpp
 		src/tz/ren/quad.cpp
 	SHADERS
+		src/tz/imgui.vertex.tzsl
+		src/tz/imgui.fragment.tzsl
 		src/tz/ren/quad.vertex.tzsl
 		src/tz/ren/quad.fragment.tzsl
 	DEFINE_PACKAGE

lib/CMakeLists.txt

@@ -48,7 +48,7 @@ add_library(imgui STATIC
 	imgui/misc/cpp/imgui_stdlib.cpp
 )
 target_include_directories(imgui PUBLIC "${PROJECT_SOURCE_DIR}/lib/imgui")
-target_compile_definitions(imgui PRIVATE "-DIMGUI_USER_CONFIG=\"${PROJECT_SOURCE_DIR}/lib/topaz_imgui_config.hpp\"")
+target_compile_definitions(imgui PUBLIC "-DIMGUI_USER_CONFIG=\"${PROJECT_SOURCE_DIR}/lib/topaz_imgui_config.hpp\"")
 
 add_library(stb_image INTERFACE)
 target_include_directories(stb_image INTERFACE stb)

src/tz/gpu/rhi_vulkan.cpp

@@ -1168,6 +1168,14 @@ namespace tz::gpu
 		pass.resources.reserve(info.resources.size());
 		for(resource_handle resh : info.resources)
 		{
+			if(resh == tz::nullhand)
+			{
+				UNERR(tz::error_code::invalid_value, "One of the resources passed into creation of pass {} was the null resource. You cannot use the null resource within a pass.", info.name);
+			}
+			if(resh == tz::gpu::window_resource)
+			{
+				UNERR(tz::error_code::invalid_value, "One of the resources passed into creation of pass {} was the window resource. You cannot use the window resource within a pass.", info.name);
+			}
 			// todo: assert not widnow resouces or nullhand
 			const auto& res = resources[resh.peek()];
 			if(res.is_buffer())

src/tz/imgui.cpp

@@ -1,17 +1,32 @@
 #include "tz/imgui.hpp"
 #include "tz/topaz.hpp"
-#include "tz/gpu/resource.hpp"
+#include "tz/core/memory.hpp"
 #include "tz/gpu/hardware.hpp"
+#include "tz/gpu/resource.hpp"
+#include "tz/gpu/shader.hpp"
+#include "tz/gpu/pass.hpp"
 #include <span>
+#include <array>
+
+#include ImportedShaderHeader(imgui, vertex)
+#include ImportedShaderHeader(imgui, fragment)
 
 namespace tz::detail
 {
 	// imgui backend initialise.
 	struct render_data
 	{
+		tz::gpu::resource_handle vertex_buffer = tz::nullhand;
+		tz::gpu::resource_handle index_buffer = tz::nullhand;
+
 		tz::gpu::resource_handle font_image = tz::nullhand;
+		tz::gpu::shader_handle shader = tz::nullhand;
+
+		tz::gpu::pass_handle pass = tz::nullhand;
 	} render;
 
+	void impl_write_vertices_and_indices(ImDrawData* draw);
+
 	void imgui_initialise()
 	{
 		ImGui::CreateContext();
@@ -30,18 +45,70 @@ namespace tz::detail
 		io.Fonts->GetTexDataAsRGBA32(&fontptr, &fontw, &fonth);
 		std::span<unsigned char> fontdata{fontptr, static_cast<std::size_t>(fontw * fonth * 4u)};
 
+		// reserve initially 1024 vertices (and indices).
+		static_assert(sizeof(tz::gpu::index_t) == sizeof(ImDrawIdx));
+		std::array<tz::gpu::index_t, 1024> initial_indices;
+		std::array<ImDrawVert, 1024> initial_vertices;
+		render.vertex_buffer = tz_must(tz::gpu::create_buffer({
+			.data = tz::view_bytes(initial_vertices),
+			.name = "ImGui Vertex Buffer"
+		}));
+
+		render.index_buffer = tz_must(tz::gpu::create_buffer({
+			.data = tz::view_bytes(initial_indices),
+			.name = "ImGui Index Buffer"
+		}));
+
 		render.font_image = tz_must(tz::gpu::create_image
 		({
 			.width = static_cast<unsigned int>(fontw),
 			.height = static_cast<unsigned int>(fonth),
 			.data = std::as_bytes(fontdata),
 			.name = "ImGui Font image"
 		}));
+
+		render.shader = tz_must(tz::gpu::create_graphics_shader(
+			ImportedShaderSource(imgui, vertex),
+			ImportedShaderSource(imgui, fragment)
+		));
+
+		tz::gpu::resource_handle resources[] =
+		{
+			render.vertex_buffer,
+			render.index_buffer,
+			render.font_image
+		};
+
+		tz::gpu::resource_handle colour_targets[] =
+		{
+			tz::gpu::window_resource
+		};
+
+		render.pass = tz_must(tz::gpu::create_pass({
+			.graphics =
+			{
+				.colour_targets = colour_targets,
+				.flags = tz::gpu::graphics_flag::dont_clear | tz::gpu::graphics_flag::no_depth_test,
+			},
+			.shader = render.shader,
+			.resources = resources,
+		}));
 	}
 
 	void imgui_terminate()
 	{
-
+		tz::gpu::destroy_pass(render.pass);
+		tz_must(tz::gpu::destroy_resource(render.font_image));
+		tz_must(tz::gpu::destroy_resource(render.index_buffer));
+		tz_must(tz::gpu::destroy_resource(render.vertex_buffer));
+		tz::gpu::destroy_shader(render.shader);
 		ImGui::DestroyContext();
 	}
+
+	// impl bits
+
+	void impl_write_vertices_and_indices(ImDrawData* draw)
+	{
+		(void)draw;
+	}
 }

src/tz/imgui.fragment.tzsl

@@ -0,0 +1,6 @@
+shader(type = fragment);
+
+void main()
+{
+
+}

src/tz/imgui.vertex.tzsl

@@ -0,0 +1,6 @@
+shader(type = vertex);
+
+void main()
+{
+
+}