From c6a5aaf5c4a020eaefe24943ecb6cf9d4eb26836 Mon Sep 17 00:00:00 2001 From: Gabriel Schneider Date: Mon, 28 Sep 2026 15:57:22 -0300 Subject: Post chain: Shadertoy passes compiled by glslc; Crt, Ripple and Glitch rewritten as Shadertoy files Stage 9 of docs/render-pipeline.md. src/gui/Post.zig runs the chain over the finished frame: each pass reads the one before, ping-pong textures between, the last writes the window; an empty chain is the direct path. The prefix (shaders/post/prefix.glsl) is ghostty's uniform block, name for name and offset for offset (tested against a copy of its Uniforms, the selection colours by their GLSL names), at SDL GPU's bindings, y down. A user's file (Shader ) is compiled by glslc with compileGlsl's own flags on a thread of its own, taken in at the next loop step; errors name the file's own lines; a failed compile keeps the last good pipeline; glslc missing is said once. The bundled passes compile with the build, through the same prefix. Crt, Ripple and Glitch are Shadertoy files, rewritten: no barrel (input is identity, tested), everything in linear light and dithered, keyed to iTime. scene_effects, crt.zig and crt.frag.glsl are gone; the core keeps no clock for the chain. ShaderAnimation off|on|always drives redraw level A: the chain alone over the retained frame (34 us CPU a redraw, measured). Shared files touched: pardes.zig (nextWake loses the scene line, disableSceneEffects empties the chain, two tests), builtins.zig (one switch arm), ninep/ctl.zig (two switch arms), macos.zig (flags from the chain), gui.zig. Not touched: Messages.zig, mouse.zig, detached/*, host_io, tty. --- shaders/post.vert.glsl | 10 ++++++++++ 1 file changed, 10 insertions(+) create mode 100644 shaders/post.vert.glsl (limited to 'shaders/post.vert.glsl') diff --git a/shaders/post.vert.glsl b/shaders/post.vert.glsl new file mode 100644 index 00000000..86739a65 --- /dev/null +++ b/shaders/post.vert.glsl @@ -0,0 +1,10 @@ +#version 450 + +// A post pass (docs/render-pipeline.md ยง6): one fullscreen triangle from +// gl_VertexIndex, no vertex buffer. The Shadertoy fragment shader works from +// gl_FragCoord, y down, as its fragCoord. + +void main() { + vec2 p = vec2(float((gl_VertexIndex << 1) & 2), float(gl_VertexIndex & 2)); + gl_Position = vec4(p * 2.0 - 1.0, 0.0, 1.0); +} -- cgit v1.3