Move all crates into a crates directory (#1940)

crates/egui_glow/src/shader/vertex.glsl

@@ -0,0 +1,43 @@
+#ifdef NEW_SHADER_INTERFACE
+    #define I in
+    #define O out
+    #define V(x) x
+#else
+    #define I attribute
+    #define O varying
+    #define V(x) vec3(x)
+#endif
+
+#ifdef GL_ES
+    precision mediump float;
+#endif
+
+uniform vec2 u_screen_size;
+I vec2 a_pos;
+I vec4 a_srgba; // 0-255 sRGB
+I vec2 a_tc;
+O vec4 v_rgba;
+O vec2 v_tc;
+
+// 0-1 linear  from  0-255 sRGB
+vec3 linear_from_srgb(vec3 srgb) {
+    bvec3 cutoff = lessThan(srgb, vec3(10.31475));
+    vec3 lower = srgb / vec3(3294.6);
+    vec3 higher = pow((srgb + vec3(14.025)) / vec3(269.025), vec3(2.4));
+    return mix(higher, lower, V(cutoff));
+}
+
+vec4 linear_from_srgba(vec4 srgba) {
+    return vec4(linear_from_srgb(srgba.rgb), srgba.a / 255.0);
+}
+
+void main() {
+    gl_Position = vec4(
+                      2.0 * a_pos.x / u_screen_size.x - 1.0,
+                      1.0 - 2.0 * a_pos.y / u_screen_size.y,
+                      0.0,
+                      1.0);
+    // egui encodes vertex colors in gamma space, so we must decode the colors here:
+    v_rgba = linear_from_srgba(a_srgba);
+    v_tc = a_tc;
+}