1 files changed, 24 insertions, 0 deletions

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;
+}