From 6c8ae19be66cee247980a48e736a4e05d14de179 Mon Sep 17 00:00:00 2001
From: 3gg <3gg@shellblade.net>
Date: Tue, 2 Dec 2025 16:39:36 -0800
Subject: Immediate-mode renderer, triangle demo, shader compilation in cmake,
 Agility SDK

---
 dxg/shaders/CMakeLists.txt | 98 ++++++++++++++++++++++++++++++++++++++++++++++
 dxg/shaders/imm.hlsl       | 23 +++++++++++
 2 files changed, 121 insertions(+)
 create mode 100644 dxg/shaders/CMakeLists.txt
 create mode 100644 dxg/shaders/imm.hlsl

(limited to 'dxg/shaders')

diff --git a/dxg/shaders/CMakeLists.txt b/dxg/shaders/CMakeLists.txt
new file mode 100644
index 0000000..c6ec687
--- /dev/null
+++ b/dxg/shaders/CMakeLists.txt
@@ -0,0 +1,98 @@
+set(SHADER_MODEL "6_5")
+set(DXC ${PROJECT_SOURCE_DIR}/../contrib/dxc_2025_07_14/bin/x64/dxc.exe)
+set(SHADERS_PATH ${CMAKE_CURRENT_SOURCE_DIR})
+set(BUILD_DIR "${CMAKE_CURRENT_BINARY_DIR}")
+
+# Compile HLSL to binary DXIL.
+#
+# This defines a custom command so that the shader is compiled at cmake build
+# instead of configure.
+#
+# hlsl_file:   "foo.hlsl"; just the file name, not the path.
+# shader_type: "vs", "ps", "cs", etc.
+# entry_point: "main", etc.
+function(compile_shader hlsl_file shader_type entry_point dxil_file)
+    #string(REPLACE ".hlsl" ".dxil" dxil_file ${hlsl_file})
+    set(hlsl_path "${SHADERS_PATH}/${hlsl_file}")
+    set(dxil_path "${BUILD_DIR}/${dxil_file}")
+    set(target_profile "${shader_type}_${SHADER_MODEL}")
+    message("COMPILING ${dxil_path}")
+    message("DXC = ${DXC}")
+    add_custom_command(
+        OUTPUT ${dxil_path}
+        COMMAND ${DXC} -T ${target_profile} -E ${entry_point} ${hlsl_path} -Fo ${dxil_path}
+        WORKING_DIRECTORY ${BUILD_DIR}
+        DEPENDS ${hlsl_path}
+        COMMENT "Generating ${dxil_path}")
+endfunction()
+
+# Inline a binary file into C code.
+# This is a workaround for the lack of C23 #embed in MSVC.
+#
+# identifier: Identifier to use for the global array that will contain the file,
+#             the generated file names, and the cmake target.
+# file_path:  Path to the binary file to embed.
+#
+# Reference: https://github.com/andoalon/embed-binaries
+function(generate_c file_path identifier out_header_path out_source_path)
+	file(READ "${file_path}" file_contents HEX)
+	string(LENGTH "${file_contents}" file_contents_length)
+	math(EXPR file_bytes "${file_contents_length} / 2")
+
+	set(bytes_per_line 32)
+    string(REPEAT "[0-9a-f]" ${bytes_per_line} column_pattern)
+    string(REGEX REPLACE "(${column_pattern})" "\\1\n" code "${file_contents}")
+    string(REGEX REPLACE "([0-9a-f][0-9a-f])" "0x\\1," code "${code}")
+
+	set(declaration "const uint8_t ${identifier}[${file_bytes}]")
+
+    string(APPEND header "#pragma once\n\n#include <stdint.h>\n\nextern ${declaration}\;\n")
+    string(APPEND implementation "#include \"${identifier}.h\"\n\n${declaration} = {\n${code}}\;\n")
+
+    file(WRITE "${BUILD_DIR}/${identifier}.h" ${header})
+    file(WRITE "${BUILD_DIR}/${identifier}.c" ${implementation})
+endfunction()
+
+# Create a target that embeds the given DXIL file in a C header/source.
+# Like compile_shader, this just adds the target so that the embedding is done
+# at cmake build and not configure.
+function(create_c_target dxil_file identifier)
+    set(dxil_path "${BUILD_DIR}/${dxil_file}")
+    string(REPLACE ".dxil" ".h" header_path ${dxil_path})
+    string(REPLACE ".dxil" ".c" source_path ${dxil_path})
+    add_custom_command(
+        OUTPUT "${header_path}" "${source_path}"
+        COMMAND ${CMAKE_COMMAND} -D dxil_path=${dxil_path} -D identifier=${identifier} -D out_header_path=${header_path} -D out_source_path=${source_path} -P ${CMAKE_CURRENT_LIST_FILE}
+        WORKING_DIRECTORY ${BUILD_DIR}
+        DEPENDS ${dxil_path}
+        COMMENT "Generating ${source_path}"
+    )
+endfunction()
+
+# Running in script mode.
+# https://stackoverflow.com/questions/51427538/cmake-test-if-i-am-in-scripting-mode
+#
+# When running in script mode, we embed the binary DXIL into a generated C file.
+if(CMAKE_SCRIPT_MODE_FILE AND NOT CMAKE_PARENT_LIST_FILE)
+    foreach(variable "dxil_path" "identifier" "out_header_path" "out_source_path")
+        if (NOT DEFINED ${variable})
+            message(FATAL_ERROR "'${variable}' is not defined")
+        endif()
+    endforeach()
+    generate_c("${dxil_path}" ${identifier} "${out_header_path}" "${out_source_path}")
+else()
+    compile_shader("imm.hlsl" "vs" "vs" "imm_vs.dxil")
+    compile_shader("imm.hlsl" "ps" "ps" "imm_ps.dxil")
+
+    create_c_target("imm_vs.dxil" "imm_vs")
+    create_c_target("imm_ps.dxil" "imm_ps")
+
+    add_library(shaders
+        "${BUILD_DIR}/imm_ps.c"
+        "${BUILD_DIR}/imm_ps.h"
+        "${BUILD_DIR}/imm_vs.c"
+        "${BUILD_DIR}/imm_vs.h")
+
+    target_include_directories(shaders PUBLIC
+        ${BUILD_DIR})
+endif()
diff --git a/dxg/shaders/imm.hlsl b/dxg/shaders/imm.hlsl
new file mode 100644
index 0000000..da6b1f6
--- /dev/null
+++ b/dxg/shaders/imm.hlsl
@@ -0,0 +1,23 @@
+struct VertexIn {
+    float3 position : POSITION;
+};
+
+struct VertexOut {
+    float4 position : SV_POSITION;
+};
+
+struct PixelOut {
+    float4 color : SV_TARGET;
+};
+
+VertexOut vs(VertexIn vin) {
+    VertexOut vout;
+    vout.position = float4(vin.position, 1.0f);
+    return vout;
+}
+
+PixelOut ps(VertexOut vout) {
+    PixelOut pixel;
+    pixel.color = float4(0.9f, 0.2f, 0.9f, 1.0f);
+    return pixel;
+}
-- 
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