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Reduce per OS Window VRAM usage for windows that use layered rendering, such as translucent windows.

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The texture used as the intermediate rendering target is now shared between
all OS Windows instead of each OS Window having its own.

Fixes #9600
Fixes #9599
This commit is contained in:
copilot-swe-agent[bot] 2026-03-04 08:04:11 +00:00 committed by Kovid Goyal
parent 0170c2c0c6
commit f7a4bf6be2
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GPG key ID: 06BC317B515ACE7C
3 changed files with 32 additions and 13 deletions
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32
kitty/shaders.c
View file

@ -1400,18 +1400,28 @@ start_os_window_rendering(OSWindow *os_window, Tab *tab) {
// note that during live resize rendering is done in layers
if (os_window->live_resize.in_progress) blank_os_window(os_window);
if (os_window->needs_layers) {
if (os_window->indirect_output.width != os_window->viewport_width || os_window->indirect_output.height != os_window->viewport_height) {
if (os_window->indirect_output.texture_id) free_texture(&os_window->indirect_output.texture_id);
if (os_window->indirect_output.framebuffer_id) free_framebuffer(&os_window->indirect_output.framebuffer_id);
// Ensure the global shared texture is large enough for this window
if (global_state.layers_render_texture.width < os_window->viewport_width ||
global_state.layers_render_texture.height < os_window->viewport_height) {
if (global_state.layers_render_texture.texture_id) free_texture(&global_state.layers_render_texture.texture_id);
if (global_state.layers_render_texture.framebuffer_id) free_framebuffer(&global_state.layers_render_texture.framebuffer_id);
unsigned new_w = (unsigned)MAX(global_state.layers_render_texture.width, os_window->viewport_width);
unsigned new_h = (unsigned)MAX(global_state.layers_render_texture.height, os_window->viewport_height);
setup_texture_as_render_target(new_w, new_h, &global_state.layers_render_texture.texture_id, &global_state.layers_render_texture.framebuffer_id);
global_state.layers_render_texture.width = (int)new_w;
global_state.layers_render_texture.height = (int)new_h;
global_state.layers_render_texture.texture_generation++;
}
if (os_window->indirect_output.texture_id == 0) {
os_window->indirect_output.width = os_window->viewport_width;
os_window->indirect_output.height = os_window->viewport_height;
setup_texture_as_render_target((unsigned) os_window->viewport_width, (unsigned)os_window->viewport_height, &os_window->indirect_output.texture_id, &os_window->indirect_output.framebuffer_id);
// Create per-window framebuffer if needed and attach the global texture to it
if (!os_window->indirect_output.framebuffer_id) glGenFramebuffers(1, &os_window->indirect_output.framebuffer_id);
if (os_window->indirect_output.attached_texture_generation != global_state.layers_render_texture.texture_generation) {
bind_framebuffer_for_output(os_window->indirect_output.framebuffer_id);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, global_state.layers_render_texture.texture_id, 0);
os_window->indirect_output.attached_texture_generation = global_state.layers_render_texture.texture_generation;
}
set_framebuffer_to_use_for_output(os_window->indirect_output.framebuffer_id);
bind_framebuffer_for_output(0);
save_viewport_using_bottom_left_origin(0, 0, os_window->indirect_output.width, os_window->indirect_output.height);
save_viewport_using_bottom_left_origin(0, 0, os_window->viewport_width, os_window->viewport_height);
clear_current_framebuffer();
draw_bg_image(os_window, tab);
}
@ -1425,8 +1435,10 @@ stop_os_window_rendering(OSWindow *os_window, Tab *tab, Window *active_window) {
bind_framebuffer_for_output(0);
bind_program(BLIT_PROGRAM);
glActiveTexture(GL_TEXTURE0 + GRAPHICS_UNIT);
glBindTexture(GL_TEXTURE_2D, os_window->indirect_output.texture_id);
glUniform4f(blit_program_layout.uniforms.src_rect, 0, 1, 1, 0);
glBindTexture(GL_TEXTURE_2D, global_state.layers_render_texture.texture_id);
float sx = global_state.layers_render_texture.width > 0 ? (float)os_window->viewport_width / (float)global_state.layers_render_texture.width : 1.f;
float sy = global_state.layers_render_texture.height > 0 ? (float)os_window->viewport_height / (float)global_state.layers_render_texture.height : 1.f;
glUniform4f(blit_program_layout.uniforms.src_rect, 0, sy, sx, 0);
glUniform4f(blit_program_layout.uniforms.dest_rect, -1, 1, 1, -1);
restore_viewport();
if (os_window->live_resize.in_progress) save_viewport_using_top_left_origin(

6
kitty/state.c
View file

@ -491,7 +491,6 @@ destroy_os_window_item(OSWindow *w) {
free(w->tabs); w->tabs = NULL;
free_bgimage(&w->bgimage, true);
zero_at_ptr(&w->bgimage);
if (w->indirect_output.texture_id) free_texture(&w->indirect_output.texture_id);
if (w->indirect_output.framebuffer_id) free_framebuffer(&w->indirect_output.framebuffer_id);
}
@ -507,6 +506,11 @@ remove_os_window(id_type os_window_id) {
REMOVER(global_state.os_windows, os_window_id, global_state.num_os_windows, destroy_os_window_item, global_state.capacity);
END_WITH_OS_WINDOW_REFS
update_os_window_references();
if (global_state.num_os_windows == 0) {
if (global_state.layers_render_texture.texture_id) free_texture(&global_state.layers_render_texture.texture_id);
if (global_state.layers_render_texture.framebuffer_id) free_framebuffer(&global_state.layers_render_texture.framebuffer_id);
global_state.layers_render_texture.width = 0; global_state.layers_render_texture.height = 0;
}
}
return found;
}

7
kitty/state.h
View file

@ -312,8 +312,7 @@ typedef struct OSWindow {
Tab *tabs;
BackgroundImage *bgimage;
struct {
uint32_t texture_id, framebuffer_id;
int width, height;
uint32_t framebuffer_id, attached_texture_generation;
} indirect_output;
unsigned int active_tab, num_tabs, capacity, last_active_tab, last_num_tabs, last_active_window_id;
bool focused_at_last_render, needs_render, needs_layers;
@ -403,6 +402,10 @@ typedef struct GlobalState {
id_type id; bool drag_started;
double x, y;
} tab_being_dragged;
struct {
uint32_t texture_id, framebuffer_id, texture_generation;
int width, height;
} layers_render_texture;
} GlobalState;
extern GlobalState global_state;