From be06669e8fb24bc0b31b9fc1ae59fc73ca009a97 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 21 Aug 2017 20:53:02 +0530
Subject: [PATCH] Ensure we dont exceed GL_MAX_TEXTURE_BUFFER_SIZE

---
 kitty/gl.h       |  2 +-
 kitty/shaders.py | 34 +++++++++++++++++++---------------
 2 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/kitty/gl.h b/kitty/gl.h
index c23d6709c..ddf6bc365 100644
--- a/kitty/gl.h
+++ b/kitty/gl.h
@@ -744,7 +744,7 @@ int add_module_gl_constants(PyObject *module) {
     GLC(GL_COMPILE_STATUS);
     GLC(GL_LINK_STATUS);
     GLC(GL_TEXTURE0); GLC(GL_TEXTURE1); GLC(GL_TEXTURE2); GLC(GL_TEXTURE3); GLC(GL_TEXTURE4); GLC(GL_TEXTURE5); GLC(GL_TEXTURE6); GLC(GL_TEXTURE7); GLC(GL_TEXTURE8);
-    GLC(GL_MAX_ARRAY_TEXTURE_LAYERS); 
+    GLC(GL_MAX_ARRAY_TEXTURE_LAYERS); GLC(GL_TEXTURE_BINDING_BUFFER); GLC(GL_MAX_TEXTURE_BUFFER_SIZE);
     GLC(GL_MAX_TEXTURE_SIZE);
     GLC(GL_TEXTURE_2D_ARRAY);
     GLC(GL_LINEAR); GLC(GL_CLAMP_TO_EDGE); GLC(GL_NEAREST);
diff --git a/kitty/shaders.py b/kitty/shaders.py
index 81985739a..f994265fb 100644
--- a/kitty/shaders.py
+++ b/kitty/shaders.py
@@ -4,28 +4,28 @@
 
 import os
 import sys
-from ctypes import addressof, sizeof
 from collections import defaultdict
+from ctypes import addressof, sizeof
 from functools import lru_cache
 from threading import Lock
 
 from .fast_data_types import (
     BOLD, GL_ARRAY_BUFFER, GL_CLAMP_TO_EDGE, GL_COMPILE_STATUS, GL_FLOAT,
     GL_FRAGMENT_SHADER, GL_LINK_STATUS, GL_MAX_ARRAY_TEXTURE_LAYERS,
-    GL_MAX_TEXTURE_SIZE, GL_NEAREST, GL_R8, GL_R32UI, GL_RED, GL_STATIC_DRAW,
-    GL_STREAM_DRAW, GL_TEXTURE0, GL_TEXTURE_2D_ARRAY, GL_TEXTURE_BUFFER,
-    GL_TEXTURE_MAG_FILTER, GL_TEXTURE_MIN_FILTER, GL_TEXTURE_WRAP_S,
-    GL_TEXTURE_WRAP_T, GL_TRUE, GL_UNPACK_ALIGNMENT, GL_UNSIGNED_BYTE,
-    GL_VERTEX_SHADER, ITALIC, SpriteMap, copy_image_sub_data, glActiveTexture,
-    glAttachShader, glBindBuffer, glBindTexture, glBindVertexArray,
-    glCompileShader, glCopyImageSubData, glCreateProgram, glCreateShader,
-    glDeleteBuffer, glDeleteProgram, glDeleteShader, glDeleteTexture,
-    glEnableVertexAttribArray, glGenBuffers, glGenTextures, glGenVertexArrays,
-    glGetAttribLocation, glGetBufferSubData, glGetIntegerv,
-    glGetProgramInfoLog, glGetProgramiv, glGetShaderInfoLog, glGetShaderiv,
-    glGetUniformLocation, glLinkProgram, glNamedBufferData, glPixelStorei,
-    glShaderSource, glTexBuffer, glTexParameteri, glTexStorage3D,
-    glTexSubImage3D, glUseProgram, glVertexAttribPointer,
+    GL_MAX_TEXTURE_BUFFER_SIZE, GL_MAX_TEXTURE_SIZE, GL_NEAREST, GL_R8,
+    GL_R32UI, GL_RED, GL_STATIC_DRAW, GL_STREAM_DRAW, GL_TEXTURE0,
+    GL_TEXTURE_2D_ARRAY, GL_TEXTURE_BUFFER, GL_TEXTURE_MAG_FILTER,
+    GL_TEXTURE_MIN_FILTER, GL_TEXTURE_WRAP_S, GL_TEXTURE_WRAP_T, GL_TRUE,
+    GL_UNPACK_ALIGNMENT, GL_UNSIGNED_BYTE, GL_VERTEX_SHADER, ITALIC, SpriteMap,
+    copy_image_sub_data, glActiveTexture, glAttachShader, glBindBuffer,
+    glBindTexture, glBindVertexArray, glCompileShader, glCopyImageSubData,
+    glCreateProgram, glCreateShader, glDeleteBuffer, glDeleteProgram,
+    glDeleteShader, glDeleteTexture, glEnableVertexAttribArray, glGenBuffers,
+    glGenTextures, glGenVertexArrays, glGetAttribLocation, glGetBufferSubData,
+    glGetIntegerv, glGetProgramInfoLog, glGetProgramiv, glGetShaderInfoLog,
+    glGetShaderiv, glGetUniformLocation, glLinkProgram, glNamedBufferData,
+    glPixelStorei, glShaderSource, glTexBuffer, glTexParameteri,
+    glTexStorage3D, glTexSubImage3D, glUseProgram, glVertexAttribPointer,
     replace_or_create_buffer
 )
 from .fonts.render import render_cell
@@ -66,6 +66,7 @@ class Sprites:
         self.texture_unit = GL_TEXTURE0 + self.sampler_num
         self.buffer_texture_unit = GL_TEXTURE0 + self.buffer_sampler_num
         self.backend = SpriteMap(glGetIntegerv(GL_MAX_TEXTURE_SIZE), glGetIntegerv(GL_MAX_ARRAY_TEXTURE_LAYERS))
+        self.max_texture_buffer_size = glGetIntegerv(GL_MAX_TEXTURE_BUFFER_SIZE)
         self.lock = Lock()
 
     def do_layout(self, cell_width=1, cell_height=1):
@@ -173,6 +174,9 @@ class Sprites:
     def set_sprite_map(self, buf_id, data, usage=GL_STREAM_DRAW):
         prev_sz = self.prev_sprite_map_sizes[buf_id]
         new_sz = sizeof(data)
+        if new_sz // 4 > self.max_texture_buffer_size:
+            raise RuntimeError(('The OpenGL implementation on your system has a max_texture_buffer_size of {} which'
+                               ' is insufficient for the sprite_map').format(self.max_texture_buffer_size))
         replace_or_create_buffer(buf_id, new_sz, prev_sz, addressof(data), usage)
         self.prev_sprite_map_sizes[buf_id] = new_sz
         if False: