5 files changed, 97 insertions, 0 deletions

diff --git a/src/video_core/host_shaders/CMakeLists.txt b/src/video_core/host_shaders/CMakeLists.txt
new file mode 100644
index 000000000..aa62363a7
--- /dev/null
+++ b/src/video_core/host_shaders/CMakeLists.txt
@@ -0,0 +1,43 @@
+set(SHADER_FILES
+    opengl_present.frag
+    opengl_present.vert
+)
+
+set(SHADER_INCLUDE ${CMAKE_CURRENT_BINARY_DIR}/include)
+set(HOST_SHADERS_INCLUDE ${SHADER_INCLUDE} PARENT_SCOPE)
+
+set(SHADER_DIR ${SHADER_INCLUDE}/video_core/host_shaders)
+add_custom_command(
+    OUTPUT
+        ${SHADER_DIR}
+    COMMAND
+        ${CMAKE_COMMAND} -E make_directory ${SHADER_DIR}
+)
+
+set(INPUT_FILE ${CMAKE_CURRENT_SOURCE_DIR}/source_shader.h.in)
+set(HEADER_GENERATOR ${CMAKE_CURRENT_SOURCE_DIR}/StringShaderHeader.cmake)
+
+foreach(FILENAME IN ITEMS ${SHADER_FILES})
+    string(REPLACE "." "_" SHADER_NAME ${FILENAME})
+    set(SOURCE_FILE ${CMAKE_CURRENT_SOURCE_DIR}/${FILENAME})
+    set(HEADER_FILE ${SHADER_DIR}/${SHADER_NAME}.h)
+    add_custom_command(
+        OUTPUT
+            ${HEADER_FILE}
+        COMMAND
+            ${CMAKE_COMMAND} -P ${HEADER_GENERATOR} ${SOURCE_FILE} ${HEADER_FILE} ${INPUT_FILE}
+        MAIN_DEPENDENCY
+            ${SOURCE_FILE}
+        DEPENDS
+            ${HEADER_GENERATOR}
+            ${INPUT_FILE}
+    )
+    set(SHADER_HEADERS ${SHADER_HEADERS} ${HEADER_FILE})
+endforeach()
+
+add_custom_target(host_shaders
+    DEPENDS
+        ${SHADER_HEADERS}
+    SOURCES
+        ${SHADER_FILES}
+)
diff --git a/src/video_core/host_shaders/StringShaderHeader.cmake b/src/video_core/host_shaders/StringShaderHeader.cmake
new file mode 100644
index 000000000..368bce0ed
--- /dev/null
+++ b/src/video_core/host_shaders/StringShaderHeader.cmake
@@ -0,0 +1,11 @@
+set(SOURCE_FILE ${CMAKE_ARGV3})
+set(HEADER_FILE ${CMAKE_ARGV4})
+set(INPUT_FILE ${CMAKE_ARGV5})
+
+get_filename_component(CONTENTS_NAME ${SOURCE_FILE} NAME)
+string(REPLACE "." "_" CONTENTS_NAME ${CONTENTS_NAME})
+string(TOUPPER ${CONTENTS_NAME} CONTENTS_NAME)
+
+file(READ ${SOURCE_FILE} CONTENTS)
+
+configure_file(${INPUT_FILE} ${HEADER_FILE} @ONLY)
diff --git a/src/video_core/host_shaders/opengl_present.frag b/src/video_core/host_shaders/opengl_present.frag
new file mode 100644
index 000000000..8a4cb024b
--- /dev/null
+++ b/src/video_core/host_shaders/opengl_present.frag
@@ -0,0 +1,10 @@
+#version 430 core
+
+layout (location = 0) in vec2 frag_tex_coord;
+layout (location = 0) out vec4 color;
+
+layout (binding = 0) uniform sampler2D color_texture;
+
+void main() {
+    color = vec4(texture(color_texture, frag_tex_coord).rgb, 1.0f);
+}
diff --git a/src/video_core/host_shaders/opengl_present.vert b/src/video_core/host_shaders/opengl_present.vert
new file mode 100644
index 000000000..2235d31a4
--- /dev/null
+++ b/src/video_core/host_shaders/opengl_present.vert
@@ -0,0 +1,24 @@
+#version 430 core
+
+out gl_PerVertex {
+    vec4 gl_Position;
+};
+
+layout (location = 0) in vec2 vert_position;
+layout (location = 1) in vec2 vert_tex_coord;
+layout (location = 0) out vec2 frag_tex_coord;
+
+// This is a truncated 3x3 matrix for 2D transformations:
+// The upper-left 2x2 submatrix performs scaling/rotation/mirroring.
+// The third column performs translation.
+// The third row could be used for projection, which we don't need in 2D. It hence is assumed to
+// implicitly be [0, 0, 1]
+layout (location = 0) uniform mat3x2 modelview_matrix;
+
+void main() {
+    // Multiply input position by the rotscale part of the matrix and then manually translate by
+    // the last column. This is equivalent to using a full 3x3 matrix and expanding the vector
+    // to `vec3(vert_position.xy, 1.0)`
+    gl_Position = vec4(mat2(modelview_matrix) * vert_position + modelview_matrix[2], 0.0, 1.0);
+    frag_tex_coord = vert_tex_coord;
+}
diff --git a/src/video_core/host_shaders/source_shader.h.in b/src/video_core/host_shaders/source_shader.h.in
new file mode 100644
index 000000000..ccdb0d2a9
--- /dev/null
+++ b/src/video_core/host_shaders/source_shader.h.in
@@ -0,0 +1,9 @@
+#pragma once
+
+#include <string_view>
+
+namespace HostShaders {
+
+constexpr std::string_view @CONTENTS_NAME@ = R"(@CONTENTS@)";
+
+} // namespace HostShaders