Dont send the color table to the GPU on every frame

kitty/cell_vertex.glsl

@@ -4,7 +4,9 @@ uniform vec4 steps;  // xstart, ystart, dx, dy
 uniform vec2 sprite_layout;  // dx, dy
 uniform ivec2 color_indices;  // which color to use as fg and which as bg
 uniform uvec4 default_colors; // The default colors
-uniform uint color_table[256]; // The color table
+uniform ColorTable {
+    uint color_table[256]; // The color table
+};
 in uvec3 sprite_coords;
 in uvec3 colors;
 in float is_selected;

kitty/char_grid.py

@@ -16,8 +16,8 @@ from .constants import (
 from .fast_data_types import (
     CURSOR_BEAM, CURSOR_BLOCK, CURSOR_UNDERLINE, DATA_CELL_SIZE, GL_BLEND,
     GL_FLOAT, GL_LINE_LOOP, GL_TRIANGLE_FAN, GL_UNSIGNED_INT, glDisable,
-    glDrawArrays, glDrawArraysInstanced, glEnable, glUniform1i, glUniform1uiv,
-    glUniform2f, glUniform2i, glUniform2ui, glUniform4f, glUniform4ui
+    glDrawArrays, glDrawArraysInstanced, glEnable, glUniform1i, glUniform2f,
+    glUniform2i, glUniform2ui, glUniform4f, glUniform4ui
 )
 from .rgb import to_color
 from .shaders import ShaderProgram, load_shaders
@@ -35,6 +35,21 @@ class DynamicColor(Enum):
 
 class CellProgram(ShaderProgram):
 
+    def __init__(self, *args):
+        ShaderProgram.__init__(self, *args)
+        self.color_table_buf = None
+
+    def send_color_table(self, color_profile):
+        if color_profile.ubo is None:
+            color_profile.ubo = self.init_uniform_block('ColorTable', 'color_table')
+        ubo = color_profile.ubo
+        if self.color_table_buf is None:
+            self.color_table_buf = (GLuint * (ubo.size // sizeof(GLuint)))()
+        offset = ubo.offsets['color_table'] // sizeof(GLuint)
+        stride = ubo.size // (256 * sizeof(GLuint))
+        color_profile.copy_color_table(addressof(self.color_table_buf), offset, stride)
+        self.send_uniform_buffer_data(ubo, self.color_table_buf)
+
     def create_sprite_map(self):
         with self.array_object_creator() as add_attribute:
             stride = DATA_CELL_SIZE * sizeof(GLuint)
@@ -124,15 +139,17 @@ def calculate_gl_geometry(window_geometry, viewport_width, viewport_height, cell
 
 
 def render_cells(vao_id, sg, cell_program, sprites, color_profile, invert_colors=False):
+    if color_profile.dirty:
+        cell_program.send_color_table(color_profile)
+        color_profile.dirty = False
     ul = cell_program.uniform_location
     glUniform2ui(ul('dimensions'), sg.xnum, sg.ynum)
     glUniform4ui(ul('default_colors'), color_profile.default_fg, color_profile.default_bg, color_profile.highlight_fg, color_profile.highlight_bg)
-    glUniform1uiv(ul('color_table'), 256, color_profile.color_table_address())
     glUniform2i(ul('color_indices'), 1 if invert_colors else 0, 0 if invert_colors else 1)
     glUniform4f(ul('steps'), sg.xstart, sg.ystart, sg.dx, sg.dy)
     glUniform1i(ul('sprites'), sprites.sampler_num)
     glUniform2f(ul('sprite_layout'), *(sprites.layout))
-    with cell_program.bound_vertex_array(vao_id):
+    with cell_program.bound_vertex_array(vao_id), cell_program.bound_uniform_buffer(color_profile.ubo):
         glDrawArraysInstanced(GL_TRIANGLE_FAN, 0, 4, sg.xnum * sg.ynum)
 
 

kitty/colors.c

@@ -61,6 +61,7 @@ new(PyTypeObject *type, PyObject UNUSED *args, PyObject UNUSED *kwds) {
         memcpy(self->color_table, FG_BG_256, sizeof(FG_BG_256));
         memcpy(self->orig_color_table, FG_BG_256, sizeof(FG_BG_256));
         self->dirty = Py_True; Py_INCREF(Py_True);
+        self->ubo = Py_None; Py_INCREF(Py_None);
     }
     return (PyObject*) self;
 }
@@ -68,6 +69,7 @@ new(PyTypeObject *type, PyObject UNUSED *args, PyObject UNUSED *kwds) {
 static void
 dealloc(ColorProfile* self) {
     Py_DECREF(self->dirty);
+    Py_DECREF(self->ubo);
     Py_TYPE(self)->tp_free((PyObject*)self);
 }
 
@@ -162,6 +164,20 @@ set_configured_colors(ColorProfile *self, PyObject *args) {
     Py_RETURN_NONE;
 }
 
+static PyObject*
+copy_color_table(ColorProfile *self, PyObject *args) {
+#define copy_color_table_doc "copy_color_table(address, offset, stride) -> copy the color table into the memory at address, using the specified offset and stride."
+    unsigned int offset, stride, i;
+    PyObject *ptr;
+    if (!PyArg_ParseTuple(args, "OII", &ptr, &offset, &stride)) return NULL;
+    color_type *buf = (color_type*)PyLong_AsVoidPtr(ptr);
+    stride = MAX(1, stride);
+    for (i = 0, buf = buf + offset; i < sizeof(self->color_table)/sizeof(self->color_table[0]); i++, buf += stride) {
+        *buf = self->color_table[i];
+    }
+    Py_RETURN_NONE;
+}
+ 
 static PyObject*
 color_table_address(ColorProfile *self) {
 #define color_table_address_doc "Pointer address to start of color table"
@@ -193,6 +209,7 @@ static PyGetSetDef getsetters[] = {
 
 static PyMemberDef members[] = {
     {"dirty", T_OBJECT_EX, offsetof(ColorProfile, dirty), 0, "dirty"},
+    {"ubo", T_OBJECT_EX, offsetof(ColorProfile, ubo), 0, "ubo"},
     {NULL}
 };
 
@@ -204,6 +221,7 @@ static PyMethodDef methods[] = {
     METHOD(reset_color, METH_O)
     METHOD(set_color, METH_VARARGS)
     METHOD(set_configured_colors, METH_VARARGS)
+    METHOD(copy_color_table, METH_VARARGS)
     {NULL}  /* Sentinel */
 };
 

kitty/data-types.h

@@ -184,7 +184,7 @@ typedef struct {
 typedef struct {
     PyObject_HEAD
 
-    PyObject *dirty;
+    PyObject *dirty, *ubo;
     uint32_t color_table[256];
     uint32_t orig_color_table[256];
     DynamicColor configured, overridden;